git/remote-curl.c

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C
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#include "cache.h"
#include "remote.h"
#include "strbuf.h"
#include "walker.h"
#include "http.h"
#include "exec_cmd.h"
#include "run-command.h"
#include "pkt-line.h"
#include "string-list.h"
#include "sideband.h"
#include "argv-array.h"
http: hoist credential request out of handle_curl_result When we are handling a curl response code in http_request or in the remote-curl RPC code, we use the handle_curl_result helper to translate curl's response into an easy-to-use code. When we see an HTTP 401, we do one of two things: 1. If we already had a filled-in credential, we mark it as rejected, and then return HTTP_NOAUTH to indicate to the caller that we failed. 2. If we didn't, then we ask for a new credential and tell the caller HTTP_REAUTH to indicate that they may want to try again. Rejecting in the first case makes sense; it is the natural result of the request we just made. However, prompting for more credentials in the second step does not always make sense. We do not know for sure that the caller is going to make a second request, and nor are we sure that it will be to the same URL. Logically, the prompt belongs not to the request we just finished, but to the request we are (maybe) about to make. In practice, it is very hard to trigger any bad behavior. Currently, if we make a second request, it will always be to the same URL (even in the face of redirects, because curl handles the redirects internally). And we almost always retry on HTTP_REAUTH these days. The one exception is if we are streaming a large RPC request to the server (e.g., a pushed packfile), in which case we cannot restart. It's extremely unlikely to see a 401 response at this stage, though, as we would typically have seen it when we sent a probe request, before streaming the data. This patch drops the automatic prompt out of case 2, and instead requires the caller to do it. This is a few extra lines of code, and the bug it fixes is unlikely to come up in practice. But it is conceptually cleaner, and paves the way for better handling of credentials across redirects. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2013-09-28 12:31:45 +04:00
#include "credential.h"
static struct remote *remote;
/* always ends with a trailing slash */
static struct strbuf url = STRBUF_INIT;
struct options {
int verbosity;
unsigned long depth;
unsigned progress : 1,
check_self_contained_and_connected : 1,
followtags : 1,
dry_run : 1,
thin : 1;
};
static struct options options;
static struct string_list cas_options = STRING_LIST_INIT_DUP;
static int set_option(const char *name, const char *value)
{
if (!strcmp(name, "verbosity")) {
char *end;
int v = strtol(value, &end, 10);
if (value == end || *end)
return -1;
options.verbosity = v;
return 0;
}
else if (!strcmp(name, "progress")) {
if (!strcmp(value, "true"))
options.progress = 1;
else if (!strcmp(value, "false"))
options.progress = 0;
else
return -1;
return 0;
}
else if (!strcmp(name, "depth")) {
char *end;
unsigned long v = strtoul(value, &end, 10);
if (value == end || *end)
return -1;
options.depth = v;
return 0;
}
else if (!strcmp(name, "followtags")) {
if (!strcmp(value, "true"))
options.followtags = 1;
else if (!strcmp(value, "false"))
options.followtags = 0;
else
return -1;
return 0;
}
else if (!strcmp(name, "dry-run")) {
if (!strcmp(value, "true"))
options.dry_run = 1;
else if (!strcmp(value, "false"))
options.dry_run = 0;
else
return -1;
return 0;
}
else if (!strcmp(name, "check-connectivity")) {
if (!strcmp(value, "true"))
options.check_self_contained_and_connected = 1;
else if (!strcmp(value, "false"))
options.check_self_contained_and_connected = 0;
else
return -1;
return 0;
}
else if (!strcmp(name, "cas")) {
struct strbuf val = STRBUF_INIT;
strbuf_addf(&val, "--" CAS_OPT_NAME "=%s", value);
string_list_append(&cas_options, val.buf);
strbuf_release(&val);
return 0;
}
else {
return 1 /* unsupported */;
}
}
struct discovery {
const char *service;
char *buf_alloc;
char *buf;
size_t len;
remote-curl: always parse incoming refs When remote-curl receives a list of refs from a server, it keeps the whole buffer intact. When we get a "list" command, we feed the result to get_remote_heads, and when we get a "fetch" or "push" command, we feed it to fetch-pack or send-pack, respectively. If the HTTP response from the server is truncated for any reason, we will get an incomplete ref advertisement. If we then feed this incomplete list to fetch-pack, one of a few things may happen: 1. If the truncation is in a packet header, fetch-pack will notice the bogus line and complain. 2. If the truncation is inside a packet, fetch-pack will keep waiting for us to send the rest of the packet, which we never will. 3. If the truncation is at a packet boundary, fetch-pack will keep waiting for us to send the next packet, which we never will. As a result, fetch-pack hangs, waiting for input. However, remote-curl believes it has sent all of the advertisement, and therefore waits for fetch-pack to speak. The two processes end up in a deadlock. We do notice the broken ref list if we feed it to get_remote_heads. So if git asks the helper to do a "list" followed by a "fetch", we are safe; we'll abort during the list operation, which parses the refs. This patch teaches remote-curl to always parse and save the incoming ref list when we read the ref advertisement from a server. That means that we will always verify and abort before even running fetch-pack (or send-pack) when reading a corrupted list, even if we do not run the "list" command explicitly. Since we save the result, in the common case of running "list" then "fetch", we do not do any extra parsing at all. In the case of just a "fetch", we do an extra round of parsing, but only once. Note also that the "fetch" case will now also initialize server_capabilities from the remote (in remote-curl; we already would do so inside fetch-pack). Doing "list+fetch" already does this. It doesn't actually matter now, but the new behavior is arguably more correct, should remote-curl ever start caring about the server's capability list. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-21 00:07:19 +04:00
struct ref *refs;
unsigned proto_git : 1;
};
static struct discovery *last_discovery;
static struct ref *parse_git_refs(struct discovery *heads, int for_push)
{
struct ref *list = NULL;
get_remote_heads(-1, heads->buf, heads->len, &list,
for_push ? REF_NORMAL : 0, NULL);
return list;
}
static struct ref *parse_info_refs(struct discovery *heads)
{
char *data, *start, *mid;
char *ref_name;
int i = 0;
struct ref *refs = NULL;
struct ref *ref = NULL;
struct ref *last_ref = NULL;
data = heads->buf;
start = NULL;
mid = data;
while (i < heads->len) {
if (!start) {
start = &data[i];
}
if (data[i] == '\t')
mid = &data[i];
if (data[i] == '\n') {
if (mid - start != 40)
die("%sinfo/refs not valid: is this a git repository?",
url.buf);
data[i] = 0;
ref_name = mid + 1;
ref = xmalloc(sizeof(struct ref) +
strlen(ref_name) + 1);
memset(ref, 0, sizeof(struct ref));
strcpy(ref->name, ref_name);
get_sha1_hex(start, ref->old_sha1);
if (!refs)
refs = ref;
if (last_ref)
last_ref->next = ref;
last_ref = ref;
start = NULL;
}
i++;
}
ref = alloc_ref("HEAD");
if (!http_fetch_ref(url.buf, ref) &&
!resolve_remote_symref(ref, refs)) {
ref->next = refs;
refs = ref;
} else {
free(ref);
}
return refs;
}
static void free_discovery(struct discovery *d)
{
if (d) {
if (d == last_discovery)
last_discovery = NULL;
free(d->buf_alloc);
remote-curl: always parse incoming refs When remote-curl receives a list of refs from a server, it keeps the whole buffer intact. When we get a "list" command, we feed the result to get_remote_heads, and when we get a "fetch" or "push" command, we feed it to fetch-pack or send-pack, respectively. If the HTTP response from the server is truncated for any reason, we will get an incomplete ref advertisement. If we then feed this incomplete list to fetch-pack, one of a few things may happen: 1. If the truncation is in a packet header, fetch-pack will notice the bogus line and complain. 2. If the truncation is inside a packet, fetch-pack will keep waiting for us to send the rest of the packet, which we never will. 3. If the truncation is at a packet boundary, fetch-pack will keep waiting for us to send the next packet, which we never will. As a result, fetch-pack hangs, waiting for input. However, remote-curl believes it has sent all of the advertisement, and therefore waits for fetch-pack to speak. The two processes end up in a deadlock. We do notice the broken ref list if we feed it to get_remote_heads. So if git asks the helper to do a "list" followed by a "fetch", we are safe; we'll abort during the list operation, which parses the refs. This patch teaches remote-curl to always parse and save the incoming ref list when we read the ref advertisement from a server. That means that we will always verify and abort before even running fetch-pack (or send-pack) when reading a corrupted list, even if we do not run the "list" command explicitly. Since we save the result, in the common case of running "list" then "fetch", we do not do any extra parsing at all. In the case of just a "fetch", we do an extra round of parsing, but only once. Note also that the "fetch" case will now also initialize server_capabilities from the remote (in remote-curl; we already would do so inside fetch-pack). Doing "list+fetch" already does this. It doesn't actually matter now, but the new behavior is arguably more correct, should remote-curl ever start caring about the server's capability list. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-21 00:07:19 +04:00
free_refs(d->refs);
free(d);
}
}
remote-curl: show server content on http errors If an http request to a remote git server fails, we show only the http response code, or sometimes a custom message for particular codes. This gives the server no opportunity to offer a more detailed explanation of the reason for the failure, or to give extra advice. This patch teaches remote-curl to record and display the body content of a failed http response. We only display such responses when the content-type is advertised as text/plain, as it is the most likely to look presentable on the user's terminal (and it is hoped to be a good indication that the message is intended for git clients, and not for a web browser). Each line of the new output is prepended with "remote:". Example output may look like this (assuming the server is configured to display such a helpful message): $ GIT_SMART_HTTP=0 git clone https://example.com/some/repo.git Cloning into 'repo'... remote: Sorry, fetching via dumb http is forbidden. remote: Please upgrade your git client to v1.6.6 or greater remote: and make sure that smart-http is enabled. error: The requested URL returned error: 403 while accessing http://localhost:5001/some/repo.git/info/refs fatal: HTTP request failed For the sake of simplicity, we only record and display these errors during the initial fetch of the ref list, as that is the initial contact with the server and where the most common, interesting errors happen (and there is already precedent, as that is the only place we currently massage http error codes into more helpful messages). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-04-06 02:17:23 +04:00
static int show_http_message(struct strbuf *type, struct strbuf *msg)
{
const char *p, *eol;
/*
* We only show text/plain parts, as other types are likely
* to be ugly to look at on the user's terminal.
*
* TODO should handle "; charset=XXX", and re-encode into
* logoutputencoding
*/
if (strcasecmp(type->buf, "text/plain"))
return -1;
strbuf_trim(msg);
if (!msg->len)
return -1;
p = msg->buf;
do {
eol = strchrnul(p, '\n');
fprintf(stderr, "remote: %.*s\n", (int)(eol - p), p);
p = eol + 1;
} while(*eol);
return 0;
}
remote-curl: always parse incoming refs When remote-curl receives a list of refs from a server, it keeps the whole buffer intact. When we get a "list" command, we feed the result to get_remote_heads, and when we get a "fetch" or "push" command, we feed it to fetch-pack or send-pack, respectively. If the HTTP response from the server is truncated for any reason, we will get an incomplete ref advertisement. If we then feed this incomplete list to fetch-pack, one of a few things may happen: 1. If the truncation is in a packet header, fetch-pack will notice the bogus line and complain. 2. If the truncation is inside a packet, fetch-pack will keep waiting for us to send the rest of the packet, which we never will. 3. If the truncation is at a packet boundary, fetch-pack will keep waiting for us to send the next packet, which we never will. As a result, fetch-pack hangs, waiting for input. However, remote-curl believes it has sent all of the advertisement, and therefore waits for fetch-pack to speak. The two processes end up in a deadlock. We do notice the broken ref list if we feed it to get_remote_heads. So if git asks the helper to do a "list" followed by a "fetch", we are safe; we'll abort during the list operation, which parses the refs. This patch teaches remote-curl to always parse and save the incoming ref list when we read the ref advertisement from a server. That means that we will always verify and abort before even running fetch-pack (or send-pack) when reading a corrupted list, even if we do not run the "list" command explicitly. Since we save the result, in the common case of running "list" then "fetch", we do not do any extra parsing at all. In the case of just a "fetch", we do an extra round of parsing, but only once. Note also that the "fetch" case will now also initialize server_capabilities from the remote (in remote-curl; we already would do so inside fetch-pack). Doing "list+fetch" already does this. It doesn't actually matter now, but the new behavior is arguably more correct, should remote-curl ever start caring about the server's capability list. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-21 00:07:19 +04:00
static struct discovery* discover_refs(const char *service, int for_push)
{
struct strbuf exp = STRBUF_INIT;
struct strbuf type = STRBUF_INIT;
struct strbuf buffer = STRBUF_INIT;
struct strbuf refs_url = STRBUF_INIT;
remote-curl: rewrite base url from info/refs redirects For efficiency and security reasons, an earlier commit in this series taught http_get_* to re-write the base url based on redirections we saw while making a specific request. This commit wires that option into the info/refs request, meaning that a redirect from http://example.com/foo.git/info/refs to https://example.com/bar.git/info/refs will behave as if "https://example.com/bar.git" had been provided to git in the first place. The tests bear some explanation. We introduce two new hierearchies into the httpd test config: 1. Requests to /smart-redir-limited will work only for the initial info/refs request, but not any subsequent requests. As a result, we can confirm whether the client is re-rooting its requests after the initial contact, since otherwise it will fail (it will ask for "repo.git/git-upload-pack", which is not redirected). 2. Requests to smart-redir-auth will redirect, and require auth after the redirection. Since we are using the redirected base for further requests, we also update the credential struct, in order not to mislead the user (or credential helpers) about which credential is needed. We can therefore check the GIT_ASKPASS prompts to make sure we are prompting for the new location. Because we have neither multiple servers nor https support in our test setup, we can only redirect between paths, meaning we need to turn on credential.useHttpPath to see the difference. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2013-09-28 12:35:35 +04:00
struct strbuf effective_url = STRBUF_INIT;
struct discovery *last = last_discovery;
int http_ret, maybe_smart = 0;
struct http_get_options options;
if (last && !strcmp(service, last->service))
return last;
free_discovery(last);
strbuf_addf(&refs_url, "%sinfo/refs", url.buf);
if ((!prefixcmp(url.buf, "http://") || !prefixcmp(url.buf, "https://")) &&
git_env_bool("GIT_SMART_HTTP", 1)) {
maybe_smart = 1;
if (!strchr(url.buf, '?'))
strbuf_addch(&refs_url, '?');
else
strbuf_addch(&refs_url, '&');
strbuf_addf(&refs_url, "service=%s", service);
}
memset(&options, 0, sizeof(options));
options.content_type = &type;
remote-curl: rewrite base url from info/refs redirects For efficiency and security reasons, an earlier commit in this series taught http_get_* to re-write the base url based on redirections we saw while making a specific request. This commit wires that option into the info/refs request, meaning that a redirect from http://example.com/foo.git/info/refs to https://example.com/bar.git/info/refs will behave as if "https://example.com/bar.git" had been provided to git in the first place. The tests bear some explanation. We introduce two new hierearchies into the httpd test config: 1. Requests to /smart-redir-limited will work only for the initial info/refs request, but not any subsequent requests. As a result, we can confirm whether the client is re-rooting its requests after the initial contact, since otherwise it will fail (it will ask for "repo.git/git-upload-pack", which is not redirected). 2. Requests to smart-redir-auth will redirect, and require auth after the redirection. Since we are using the redirected base for further requests, we also update the credential struct, in order not to mislead the user (or credential helpers) about which credential is needed. We can therefore check the GIT_ASKPASS prompts to make sure we are prompting for the new location. Because we have neither multiple servers nor https support in our test setup, we can only redirect between paths, meaning we need to turn on credential.useHttpPath to see the difference. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2013-09-28 12:35:35 +04:00
options.effective_url = &effective_url;
options.base_url = &url;
options.no_cache = 1;
options.keep_error = 1;
http_ret = http_get_strbuf(refs_url.buf, &buffer, &options);
switch (http_ret) {
case HTTP_OK:
break;
case HTTP_MISSING_TARGET:
remote-curl: always show friendlier 404 message When we get an http 404 trying to get the initial list of refs from the server, we try to be helpful and remind the user that update-server-info may need to be run. This looks like: $ git clone https://github.com/non/existent Cloning into 'existent'... fatal: https://github.com/non/existent/info/refs?service=git-upload-pack not found: did you run git update-server-info on the server? Suggesting update-server-info may be a good suggestion for users who are in control of the server repo and who are planning to set up dumb http. But for users of smart http, and especially users who are not in control of the server repo, the advice is useless and confusing. Since most people are expected to use smart http these days, it does not make sense to keep the update-server-info hint. We not only drop the mention of update-server-info, but also show only the main repo URL, not the full "info/refs" and service parameter. These elements may be useful for debugging a broken server configuration, but in the majority of cases, users are not fetching from their own repositories, but rather from other people's repositories; they have neither the power nor interest to fix a broken configuration, and the extra components just make the message more confusing. Users who do want to debug can and should use GIT_CURL_VERBOSE to get more complete information on the actual URLs visited. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-04-06 02:20:43 +04:00
show_http_message(&type, &buffer);
die("repository '%s' not found", url.buf);
case HTTP_NOAUTH:
remote-curl: show server content on http errors If an http request to a remote git server fails, we show only the http response code, or sometimes a custom message for particular codes. This gives the server no opportunity to offer a more detailed explanation of the reason for the failure, or to give extra advice. This patch teaches remote-curl to record and display the body content of a failed http response. We only display such responses when the content-type is advertised as text/plain, as it is the most likely to look presentable on the user's terminal (and it is hoped to be a good indication that the message is intended for git clients, and not for a web browser). Each line of the new output is prepended with "remote:". Example output may look like this (assuming the server is configured to display such a helpful message): $ GIT_SMART_HTTP=0 git clone https://example.com/some/repo.git Cloning into 'repo'... remote: Sorry, fetching via dumb http is forbidden. remote: Please upgrade your git client to v1.6.6 or greater remote: and make sure that smart-http is enabled. error: The requested URL returned error: 403 while accessing http://localhost:5001/some/repo.git/info/refs fatal: HTTP request failed For the sake of simplicity, we only record and display these errors during the initial fetch of the ref list, as that is the initial contact with the server and where the most common, interesting errors happen (and there is already precedent, as that is the only place we currently massage http error codes into more helpful messages). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-04-06 02:17:23 +04:00
show_http_message(&type, &buffer);
die("Authentication failed for '%s'", url.buf);
default:
remote-curl: show server content on http errors If an http request to a remote git server fails, we show only the http response code, or sometimes a custom message for particular codes. This gives the server no opportunity to offer a more detailed explanation of the reason for the failure, or to give extra advice. This patch teaches remote-curl to record and display the body content of a failed http response. We only display such responses when the content-type is advertised as text/plain, as it is the most likely to look presentable on the user's terminal (and it is hoped to be a good indication that the message is intended for git clients, and not for a web browser). Each line of the new output is prepended with "remote:". Example output may look like this (assuming the server is configured to display such a helpful message): $ GIT_SMART_HTTP=0 git clone https://example.com/some/repo.git Cloning into 'repo'... remote: Sorry, fetching via dumb http is forbidden. remote: Please upgrade your git client to v1.6.6 or greater remote: and make sure that smart-http is enabled. error: The requested URL returned error: 403 while accessing http://localhost:5001/some/repo.git/info/refs fatal: HTTP request failed For the sake of simplicity, we only record and display these errors during the initial fetch of the ref list, as that is the initial contact with the server and where the most common, interesting errors happen (and there is already precedent, as that is the only place we currently massage http error codes into more helpful messages). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-04-06 02:17:23 +04:00
show_http_message(&type, &buffer);
die("unable to access '%s': %s", url.buf, curl_errorstr);
}
last= xcalloc(1, sizeof(*last_discovery));
last->service = service;
last->buf_alloc = strbuf_detach(&buffer, &last->len);
last->buf = last->buf_alloc;
strbuf_addf(&exp, "application/x-%s-advertisement", service);
if (maybe_smart &&
(5 <= last->len && last->buf[4] == '#') &&
!strbuf_cmp(&exp, &type)) {
pkt-line: share buffer/descriptor reading implementation The packet_read function reads from a descriptor. The packet_get_line function is similar, but reads from an in-memory buffer, and uses a completely separate implementation. This patch teaches the generic packet_read function to accept either source, and we can do away with packet_get_line's implementation. There are two other differences to account for between the old and new functions. The first is that we used to read into a strbuf, but now read into a fixed size buffer. The only two callers are fine with that, and in fact it simplifies their code, since they can use the same static-buffer interface as the rest of the packet_read_line callers (and we provide a similar convenience wrapper for reading from a buffer rather than a descriptor). This is technically an externally-visible behavior change in that we used to accept arbitrary sized packets up to 65532 bytes, and now cap out at LARGE_PACKET_MAX, 65520. In practice this doesn't matter, as we use it only for parsing smart-http headers (of which there is exactly one defined, and it is small and fixed-size). And any extension headers would be breaking the protocol to go over LARGE_PACKET_MAX anyway. The other difference is that packet_get_line would return on error rather than dying. However, both callers of packet_get_line are actually improved by dying. The first caller does its own error checking, but we can drop that; as a result, we'll actually get more specific reporting about protocol breakage when packet_read dies internally. The only downside is that packet_read will not print the smart-http URL that failed, but that's not a big deal; anybody not debugging can already see the remote's URL already, and anybody debugging would want to run with GIT_CURL_VERBOSE anyway to see way more information. The second caller, which is just trying to skip past any extra smart-http headers (of which there are none defined, but which we allow to keep room for future expansion), did not error check at all. As a result, it would treat an error just like a flush packet. The resulting mess would generally cause an error later in get_remote_heads, but now we get error reporting much closer to the source of the problem. Brown-paper-bag-fixes-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-24 02:31:34 +04:00
char *line;
/*
* smart HTTP response; validate that the service
* pkt-line matches our request.
*/
pkt-line: share buffer/descriptor reading implementation The packet_read function reads from a descriptor. The packet_get_line function is similar, but reads from an in-memory buffer, and uses a completely separate implementation. This patch teaches the generic packet_read function to accept either source, and we can do away with packet_get_line's implementation. There are two other differences to account for between the old and new functions. The first is that we used to read into a strbuf, but now read into a fixed size buffer. The only two callers are fine with that, and in fact it simplifies their code, since they can use the same static-buffer interface as the rest of the packet_read_line callers (and we provide a similar convenience wrapper for reading from a buffer rather than a descriptor). This is technically an externally-visible behavior change in that we used to accept arbitrary sized packets up to 65532 bytes, and now cap out at LARGE_PACKET_MAX, 65520. In practice this doesn't matter, as we use it only for parsing smart-http headers (of which there is exactly one defined, and it is small and fixed-size). And any extension headers would be breaking the protocol to go over LARGE_PACKET_MAX anyway. The other difference is that packet_get_line would return on error rather than dying. However, both callers of packet_get_line are actually improved by dying. The first caller does its own error checking, but we can drop that; as a result, we'll actually get more specific reporting about protocol breakage when packet_read dies internally. The only downside is that packet_read will not print the smart-http URL that failed, but that's not a big deal; anybody not debugging can already see the remote's URL already, and anybody debugging would want to run with GIT_CURL_VERBOSE anyway to see way more information. The second caller, which is just trying to skip past any extra smart-http headers (of which there are none defined, but which we allow to keep room for future expansion), did not error check at all. As a result, it would treat an error just like a flush packet. The resulting mess would generally cause an error later in get_remote_heads, but now we get error reporting much closer to the source of the problem. Brown-paper-bag-fixes-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-24 02:31:34 +04:00
line = packet_read_line_buf(&last->buf, &last->len, NULL);
strbuf_reset(&exp);
strbuf_addf(&exp, "# service=%s", service);
pkt-line: share buffer/descriptor reading implementation The packet_read function reads from a descriptor. The packet_get_line function is similar, but reads from an in-memory buffer, and uses a completely separate implementation. This patch teaches the generic packet_read function to accept either source, and we can do away with packet_get_line's implementation. There are two other differences to account for between the old and new functions. The first is that we used to read into a strbuf, but now read into a fixed size buffer. The only two callers are fine with that, and in fact it simplifies their code, since they can use the same static-buffer interface as the rest of the packet_read_line callers (and we provide a similar convenience wrapper for reading from a buffer rather than a descriptor). This is technically an externally-visible behavior change in that we used to accept arbitrary sized packets up to 65532 bytes, and now cap out at LARGE_PACKET_MAX, 65520. In practice this doesn't matter, as we use it only for parsing smart-http headers (of which there is exactly one defined, and it is small and fixed-size). And any extension headers would be breaking the protocol to go over LARGE_PACKET_MAX anyway. The other difference is that packet_get_line would return on error rather than dying. However, both callers of packet_get_line are actually improved by dying. The first caller does its own error checking, but we can drop that; as a result, we'll actually get more specific reporting about protocol breakage when packet_read dies internally. The only downside is that packet_read will not print the smart-http URL that failed, but that's not a big deal; anybody not debugging can already see the remote's URL already, and anybody debugging would want to run with GIT_CURL_VERBOSE anyway to see way more information. The second caller, which is just trying to skip past any extra smart-http headers (of which there are none defined, but which we allow to keep room for future expansion), did not error check at all. As a result, it would treat an error just like a flush packet. The resulting mess would generally cause an error later in get_remote_heads, but now we get error reporting much closer to the source of the problem. Brown-paper-bag-fixes-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-24 02:31:34 +04:00
if (strcmp(line, exp.buf))
die("invalid server response; got '%s'", line);
strbuf_release(&exp);
/* The header can include additional metadata lines, up
* until a packet flush marker. Ignore these now, but
* in the future we might start to scan them.
*/
pkt-line: share buffer/descriptor reading implementation The packet_read function reads from a descriptor. The packet_get_line function is similar, but reads from an in-memory buffer, and uses a completely separate implementation. This patch teaches the generic packet_read function to accept either source, and we can do away with packet_get_line's implementation. There are two other differences to account for between the old and new functions. The first is that we used to read into a strbuf, but now read into a fixed size buffer. The only two callers are fine with that, and in fact it simplifies their code, since they can use the same static-buffer interface as the rest of the packet_read_line callers (and we provide a similar convenience wrapper for reading from a buffer rather than a descriptor). This is technically an externally-visible behavior change in that we used to accept arbitrary sized packets up to 65532 bytes, and now cap out at LARGE_PACKET_MAX, 65520. In practice this doesn't matter, as we use it only for parsing smart-http headers (of which there is exactly one defined, and it is small and fixed-size). And any extension headers would be breaking the protocol to go over LARGE_PACKET_MAX anyway. The other difference is that packet_get_line would return on error rather than dying. However, both callers of packet_get_line are actually improved by dying. The first caller does its own error checking, but we can drop that; as a result, we'll actually get more specific reporting about protocol breakage when packet_read dies internally. The only downside is that packet_read will not print the smart-http URL that failed, but that's not a big deal; anybody not debugging can already see the remote's URL already, and anybody debugging would want to run with GIT_CURL_VERBOSE anyway to see way more information. The second caller, which is just trying to skip past any extra smart-http headers (of which there are none defined, but which we allow to keep room for future expansion), did not error check at all. As a result, it would treat an error just like a flush packet. The resulting mess would generally cause an error later in get_remote_heads, but now we get error reporting much closer to the source of the problem. Brown-paper-bag-fixes-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-24 02:31:34 +04:00
while (packet_read_line_buf(&last->buf, &last->len, NULL))
;
last->proto_git = 1;
}
remote-curl: always parse incoming refs When remote-curl receives a list of refs from a server, it keeps the whole buffer intact. When we get a "list" command, we feed the result to get_remote_heads, and when we get a "fetch" or "push" command, we feed it to fetch-pack or send-pack, respectively. If the HTTP response from the server is truncated for any reason, we will get an incomplete ref advertisement. If we then feed this incomplete list to fetch-pack, one of a few things may happen: 1. If the truncation is in a packet header, fetch-pack will notice the bogus line and complain. 2. If the truncation is inside a packet, fetch-pack will keep waiting for us to send the rest of the packet, which we never will. 3. If the truncation is at a packet boundary, fetch-pack will keep waiting for us to send the next packet, which we never will. As a result, fetch-pack hangs, waiting for input. However, remote-curl believes it has sent all of the advertisement, and therefore waits for fetch-pack to speak. The two processes end up in a deadlock. We do notice the broken ref list if we feed it to get_remote_heads. So if git asks the helper to do a "list" followed by a "fetch", we are safe; we'll abort during the list operation, which parses the refs. This patch teaches remote-curl to always parse and save the incoming ref list when we read the ref advertisement from a server. That means that we will always verify and abort before even running fetch-pack (or send-pack) when reading a corrupted list, even if we do not run the "list" command explicitly. Since we save the result, in the common case of running "list" then "fetch", we do not do any extra parsing at all. In the case of just a "fetch", we do an extra round of parsing, but only once. Note also that the "fetch" case will now also initialize server_capabilities from the remote (in remote-curl; we already would do so inside fetch-pack). Doing "list+fetch" already does this. It doesn't actually matter now, but the new behavior is arguably more correct, should remote-curl ever start caring about the server's capability list. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-21 00:07:19 +04:00
if (last->proto_git)
last->refs = parse_git_refs(last, for_push);
else
last->refs = parse_info_refs(last);
strbuf_release(&refs_url);
strbuf_release(&exp);
strbuf_release(&type);
remote-curl: rewrite base url from info/refs redirects For efficiency and security reasons, an earlier commit in this series taught http_get_* to re-write the base url based on redirections we saw while making a specific request. This commit wires that option into the info/refs request, meaning that a redirect from http://example.com/foo.git/info/refs to https://example.com/bar.git/info/refs will behave as if "https://example.com/bar.git" had been provided to git in the first place. The tests bear some explanation. We introduce two new hierearchies into the httpd test config: 1. Requests to /smart-redir-limited will work only for the initial info/refs request, but not any subsequent requests. As a result, we can confirm whether the client is re-rooting its requests after the initial contact, since otherwise it will fail (it will ask for "repo.git/git-upload-pack", which is not redirected). 2. Requests to smart-redir-auth will redirect, and require auth after the redirection. Since we are using the redirected base for further requests, we also update the credential struct, in order not to mislead the user (or credential helpers) about which credential is needed. We can therefore check the GIT_ASKPASS prompts to make sure we are prompting for the new location. Because we have neither multiple servers nor https support in our test setup, we can only redirect between paths, meaning we need to turn on credential.useHttpPath to see the difference. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2013-09-28 12:35:35 +04:00
strbuf_release(&effective_url);
strbuf_release(&buffer);
last_discovery = last;
return last;
}
static struct ref *get_refs(int for_push)
{
struct discovery *heads;
if (for_push)
remote-curl: always parse incoming refs When remote-curl receives a list of refs from a server, it keeps the whole buffer intact. When we get a "list" command, we feed the result to get_remote_heads, and when we get a "fetch" or "push" command, we feed it to fetch-pack or send-pack, respectively. If the HTTP response from the server is truncated for any reason, we will get an incomplete ref advertisement. If we then feed this incomplete list to fetch-pack, one of a few things may happen: 1. If the truncation is in a packet header, fetch-pack will notice the bogus line and complain. 2. If the truncation is inside a packet, fetch-pack will keep waiting for us to send the rest of the packet, which we never will. 3. If the truncation is at a packet boundary, fetch-pack will keep waiting for us to send the next packet, which we never will. As a result, fetch-pack hangs, waiting for input. However, remote-curl believes it has sent all of the advertisement, and therefore waits for fetch-pack to speak. The two processes end up in a deadlock. We do notice the broken ref list if we feed it to get_remote_heads. So if git asks the helper to do a "list" followed by a "fetch", we are safe; we'll abort during the list operation, which parses the refs. This patch teaches remote-curl to always parse and save the incoming ref list when we read the ref advertisement from a server. That means that we will always verify and abort before even running fetch-pack (or send-pack) when reading a corrupted list, even if we do not run the "list" command explicitly. Since we save the result, in the common case of running "list" then "fetch", we do not do any extra parsing at all. In the case of just a "fetch", we do an extra round of parsing, but only once. Note also that the "fetch" case will now also initialize server_capabilities from the remote (in remote-curl; we already would do so inside fetch-pack). Doing "list+fetch" already does this. It doesn't actually matter now, but the new behavior is arguably more correct, should remote-curl ever start caring about the server's capability list. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-21 00:07:19 +04:00
heads = discover_refs("git-receive-pack", for_push);
else
remote-curl: always parse incoming refs When remote-curl receives a list of refs from a server, it keeps the whole buffer intact. When we get a "list" command, we feed the result to get_remote_heads, and when we get a "fetch" or "push" command, we feed it to fetch-pack or send-pack, respectively. If the HTTP response from the server is truncated for any reason, we will get an incomplete ref advertisement. If we then feed this incomplete list to fetch-pack, one of a few things may happen: 1. If the truncation is in a packet header, fetch-pack will notice the bogus line and complain. 2. If the truncation is inside a packet, fetch-pack will keep waiting for us to send the rest of the packet, which we never will. 3. If the truncation is at a packet boundary, fetch-pack will keep waiting for us to send the next packet, which we never will. As a result, fetch-pack hangs, waiting for input. However, remote-curl believes it has sent all of the advertisement, and therefore waits for fetch-pack to speak. The two processes end up in a deadlock. We do notice the broken ref list if we feed it to get_remote_heads. So if git asks the helper to do a "list" followed by a "fetch", we are safe; we'll abort during the list operation, which parses the refs. This patch teaches remote-curl to always parse and save the incoming ref list when we read the ref advertisement from a server. That means that we will always verify and abort before even running fetch-pack (or send-pack) when reading a corrupted list, even if we do not run the "list" command explicitly. Since we save the result, in the common case of running "list" then "fetch", we do not do any extra parsing at all. In the case of just a "fetch", we do an extra round of parsing, but only once. Note also that the "fetch" case will now also initialize server_capabilities from the remote (in remote-curl; we already would do so inside fetch-pack). Doing "list+fetch" already does this. It doesn't actually matter now, but the new behavior is arguably more correct, should remote-curl ever start caring about the server's capability list. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-21 00:07:19 +04:00
heads = discover_refs("git-upload-pack", for_push);
remote-curl: always parse incoming refs When remote-curl receives a list of refs from a server, it keeps the whole buffer intact. When we get a "list" command, we feed the result to get_remote_heads, and when we get a "fetch" or "push" command, we feed it to fetch-pack or send-pack, respectively. If the HTTP response from the server is truncated for any reason, we will get an incomplete ref advertisement. If we then feed this incomplete list to fetch-pack, one of a few things may happen: 1. If the truncation is in a packet header, fetch-pack will notice the bogus line and complain. 2. If the truncation is inside a packet, fetch-pack will keep waiting for us to send the rest of the packet, which we never will. 3. If the truncation is at a packet boundary, fetch-pack will keep waiting for us to send the next packet, which we never will. As a result, fetch-pack hangs, waiting for input. However, remote-curl believes it has sent all of the advertisement, and therefore waits for fetch-pack to speak. The two processes end up in a deadlock. We do notice the broken ref list if we feed it to get_remote_heads. So if git asks the helper to do a "list" followed by a "fetch", we are safe; we'll abort during the list operation, which parses the refs. This patch teaches remote-curl to always parse and save the incoming ref list when we read the ref advertisement from a server. That means that we will always verify and abort before even running fetch-pack (or send-pack) when reading a corrupted list, even if we do not run the "list" command explicitly. Since we save the result, in the common case of running "list" then "fetch", we do not do any extra parsing at all. In the case of just a "fetch", we do an extra round of parsing, but only once. Note also that the "fetch" case will now also initialize server_capabilities from the remote (in remote-curl; we already would do so inside fetch-pack). Doing "list+fetch" already does this. It doesn't actually matter now, but the new behavior is arguably more correct, should remote-curl ever start caring about the server's capability list. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-21 00:07:19 +04:00
return heads->refs;
}
static void output_refs(struct ref *refs)
{
struct ref *posn;
for (posn = refs; posn; posn = posn->next) {
if (posn->symref)
printf("@%s %s\n", posn->symref, posn->name);
else
printf("%s %s\n", sha1_to_hex(posn->old_sha1), posn->name);
}
printf("\n");
fflush(stdout);
}
struct rpc_state {
const char *service_name;
const char **argv;
struct strbuf *stdin_preamble;
char *service_url;
char *hdr_content_type;
char *hdr_accept;
char *buf;
size_t alloc;
size_t len;
size_t pos;
int in;
int out;
struct strbuf result;
unsigned gzip_request : 1;
unsigned initial_buffer : 1;
};
static size_t rpc_out(void *ptr, size_t eltsize,
size_t nmemb, void *buffer_)
{
size_t max = eltsize * nmemb;
struct rpc_state *rpc = buffer_;
size_t avail = rpc->len - rpc->pos;
if (!avail) {
rpc->initial_buffer = 0;
pkt-line: share buffer/descriptor reading implementation The packet_read function reads from a descriptor. The packet_get_line function is similar, but reads from an in-memory buffer, and uses a completely separate implementation. This patch teaches the generic packet_read function to accept either source, and we can do away with packet_get_line's implementation. There are two other differences to account for between the old and new functions. The first is that we used to read into a strbuf, but now read into a fixed size buffer. The only two callers are fine with that, and in fact it simplifies their code, since they can use the same static-buffer interface as the rest of the packet_read_line callers (and we provide a similar convenience wrapper for reading from a buffer rather than a descriptor). This is technically an externally-visible behavior change in that we used to accept arbitrary sized packets up to 65532 bytes, and now cap out at LARGE_PACKET_MAX, 65520. In practice this doesn't matter, as we use it only for parsing smart-http headers (of which there is exactly one defined, and it is small and fixed-size). And any extension headers would be breaking the protocol to go over LARGE_PACKET_MAX anyway. The other difference is that packet_get_line would return on error rather than dying. However, both callers of packet_get_line are actually improved by dying. The first caller does its own error checking, but we can drop that; as a result, we'll actually get more specific reporting about protocol breakage when packet_read dies internally. The only downside is that packet_read will not print the smart-http URL that failed, but that's not a big deal; anybody not debugging can already see the remote's URL already, and anybody debugging would want to run with GIT_CURL_VERBOSE anyway to see way more information. The second caller, which is just trying to skip past any extra smart-http headers (of which there are none defined, but which we allow to keep room for future expansion), did not error check at all. As a result, it would treat an error just like a flush packet. The resulting mess would generally cause an error later in get_remote_heads, but now we get error reporting much closer to the source of the problem. Brown-paper-bag-fixes-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-24 02:31:34 +04:00
avail = packet_read(rpc->out, NULL, NULL, rpc->buf, rpc->alloc, 0);
if (!avail)
return 0;
rpc->pos = 0;
rpc->len = avail;
}
if (max < avail)
avail = max;
memcpy(ptr, rpc->buf + rpc->pos, avail);
rpc->pos += avail;
return avail;
}
#ifndef NO_CURL_IOCTL
static curlioerr rpc_ioctl(CURL *handle, int cmd, void *clientp)
{
struct rpc_state *rpc = clientp;
switch (cmd) {
case CURLIOCMD_NOP:
return CURLIOE_OK;
case CURLIOCMD_RESTARTREAD:
if (rpc->initial_buffer) {
rpc->pos = 0;
return CURLIOE_OK;
}
fprintf(stderr, "Unable to rewind rpc post data - try increasing http.postBuffer\n");
return CURLIOE_FAILRESTART;
default:
return CURLIOE_UNKNOWNCMD;
}
}
#endif
static size_t rpc_in(char *ptr, size_t eltsize,
size_t nmemb, void *buffer_)
{
size_t size = eltsize * nmemb;
struct rpc_state *rpc = buffer_;
write_or_die(rpc->in, ptr, size);
return size;
}
static int run_slot(struct active_request_slot *slot)
{
http: prompt for credentials on failed POST All of the smart-http GET requests go through the http_get_* functions, which will prompt for credentials and retry if we see an HTTP 401. POST requests, however, do not go through any central point. Moreover, it is difficult to retry in the general case; we cannot assume the request body fits in memory or is even seekable, and we don't know how much of it was consumed during the attempt. Most of the time, this is not a big deal; for both fetching and pushing, we make a GET request before doing any POSTs, so typically we figure out the credentials during the first request, then reuse them during the POST. However, some servers may allow a client to get the list of refs from receive-pack without authentication, and then require authentication when the client actually tries to POST the pack. This is not ideal, as the client may do a non-trivial amount of work to generate the pack (e.g., delta-compressing objects). However, for a long time it has been the recommended example configuration in git-http-backend(1) for setting up a repository with anonymous fetch and authenticated push. This setup has always been broken without putting a username into the URL. Prior to commit 986bbc0, it did work with a username in the URL, because git would prompt for credentials before making any requests at all. However, post-986bbc0, it is totally broken. Since it has been advertised in the manpage for some time, we should make sure it works. Unfortunately, it is not as easy as simply calling post_rpc again when it fails, due to the input issue mentioned above. However, we can still make this specific case work by retrying in two specific instances: 1. If the request is large (bigger than LARGE_PACKET_MAX), we will first send a probe request with a single flush packet. Since this request is static, we can freely retry it. 2. If the request is small and we are not using gzip, then we have the whole thing in-core, and we can freely retry. That means we will not retry in some instances, including: 1. If we are using gzip. However, we only do so when calling git-upload-pack, so it does not apply to pushes. 2. If we have a large request, the probe succeeds, but then the real POST wants authentication. This is an extremely unlikely configuration and not worth worrying about. While it might be nice to cover those instances, doing so would be significantly more complex for very little real-world gain. In the long run, we will be much better off when curl learns to internally handle authentication as a callback, and we can cleanly handle all cases that way. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-08-27 17:27:15 +04:00
int err;
struct slot_results results;
slot->results = &results;
slot->curl_result = curl_easy_perform(slot->curl);
finish_active_slot(slot);
err = handle_curl_result(&results);
http: prompt for credentials on failed POST All of the smart-http GET requests go through the http_get_* functions, which will prompt for credentials and retry if we see an HTTP 401. POST requests, however, do not go through any central point. Moreover, it is difficult to retry in the general case; we cannot assume the request body fits in memory or is even seekable, and we don't know how much of it was consumed during the attempt. Most of the time, this is not a big deal; for both fetching and pushing, we make a GET request before doing any POSTs, so typically we figure out the credentials during the first request, then reuse them during the POST. However, some servers may allow a client to get the list of refs from receive-pack without authentication, and then require authentication when the client actually tries to POST the pack. This is not ideal, as the client may do a non-trivial amount of work to generate the pack (e.g., delta-compressing objects). However, for a long time it has been the recommended example configuration in git-http-backend(1) for setting up a repository with anonymous fetch and authenticated push. This setup has always been broken without putting a username into the URL. Prior to commit 986bbc0, it did work with a username in the URL, because git would prompt for credentials before making any requests at all. However, post-986bbc0, it is totally broken. Since it has been advertised in the manpage for some time, we should make sure it works. Unfortunately, it is not as easy as simply calling post_rpc again when it fails, due to the input issue mentioned above. However, we can still make this specific case work by retrying in two specific instances: 1. If the request is large (bigger than LARGE_PACKET_MAX), we will first send a probe request with a single flush packet. Since this request is static, we can freely retry it. 2. If the request is small and we are not using gzip, then we have the whole thing in-core, and we can freely retry. That means we will not retry in some instances, including: 1. If we are using gzip. However, we only do so when calling git-upload-pack, so it does not apply to pushes. 2. If we have a large request, the probe succeeds, but then the real POST wants authentication. This is an extremely unlikely configuration and not worth worrying about. While it might be nice to cover those instances, doing so would be significantly more complex for very little real-world gain. In the long run, we will be much better off when curl learns to internally handle authentication as a callback, and we can cleanly handle all cases that way. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-08-27 17:27:15 +04:00
if (err != HTTP_OK && err != HTTP_REAUTH) {
error("RPC failed; result=%d, HTTP code = %ld",
results.curl_result, results.http_code);
}
return err;
}
static int probe_rpc(struct rpc_state *rpc)
{
struct active_request_slot *slot;
struct curl_slist *headers = NULL;
struct strbuf buf = STRBUF_INIT;
int err;
slot = get_active_slot();
headers = curl_slist_append(headers, rpc->hdr_content_type);
headers = curl_slist_append(headers, rpc->hdr_accept);
curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
curl_easy_setopt(slot->curl, CURLOPT_POST, 1);
curl_easy_setopt(slot->curl, CURLOPT_URL, rpc->service_url);
curl_easy_setopt(slot->curl, CURLOPT_ENCODING, NULL);
curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, "0000");
curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDSIZE, 4);
curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
curl_easy_setopt(slot->curl, CURLOPT_FILE, &buf);
err = run_slot(slot);
curl_slist_free_all(headers);
strbuf_release(&buf);
return err;
}
static int post_rpc(struct rpc_state *rpc)
{
struct active_request_slot *slot;
struct curl_slist *headers = NULL;
int use_gzip = rpc->gzip_request;
char *gzip_body = NULL;
size_t gzip_size = 0;
int err, large_request = 0;
/* Try to load the entire request, if we can fit it into the
* allocated buffer space we can use HTTP/1.0 and avoid the
* chunked encoding mess.
*/
while (1) {
size_t left = rpc->alloc - rpc->len;
char *buf = rpc->buf + rpc->len;
int n;
if (left < LARGE_PACKET_MAX) {
large_request = 1;
use_gzip = 0;
break;
}
pkt-line: share buffer/descriptor reading implementation The packet_read function reads from a descriptor. The packet_get_line function is similar, but reads from an in-memory buffer, and uses a completely separate implementation. This patch teaches the generic packet_read function to accept either source, and we can do away with packet_get_line's implementation. There are two other differences to account for between the old and new functions. The first is that we used to read into a strbuf, but now read into a fixed size buffer. The only two callers are fine with that, and in fact it simplifies their code, since they can use the same static-buffer interface as the rest of the packet_read_line callers (and we provide a similar convenience wrapper for reading from a buffer rather than a descriptor). This is technically an externally-visible behavior change in that we used to accept arbitrary sized packets up to 65532 bytes, and now cap out at LARGE_PACKET_MAX, 65520. In practice this doesn't matter, as we use it only for parsing smart-http headers (of which there is exactly one defined, and it is small and fixed-size). And any extension headers would be breaking the protocol to go over LARGE_PACKET_MAX anyway. The other difference is that packet_get_line would return on error rather than dying. However, both callers of packet_get_line are actually improved by dying. The first caller does its own error checking, but we can drop that; as a result, we'll actually get more specific reporting about protocol breakage when packet_read dies internally. The only downside is that packet_read will not print the smart-http URL that failed, but that's not a big deal; anybody not debugging can already see the remote's URL already, and anybody debugging would want to run with GIT_CURL_VERBOSE anyway to see way more information. The second caller, which is just trying to skip past any extra smart-http headers (of which there are none defined, but which we allow to keep room for future expansion), did not error check at all. As a result, it would treat an error just like a flush packet. The resulting mess would generally cause an error later in get_remote_heads, but now we get error reporting much closer to the source of the problem. Brown-paper-bag-fixes-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-24 02:31:34 +04:00
n = packet_read(rpc->out, NULL, NULL, buf, left, 0);
if (!n)
break;
rpc->len += n;
}
if (large_request) {
http: prompt for credentials on failed POST All of the smart-http GET requests go through the http_get_* functions, which will prompt for credentials and retry if we see an HTTP 401. POST requests, however, do not go through any central point. Moreover, it is difficult to retry in the general case; we cannot assume the request body fits in memory or is even seekable, and we don't know how much of it was consumed during the attempt. Most of the time, this is not a big deal; for both fetching and pushing, we make a GET request before doing any POSTs, so typically we figure out the credentials during the first request, then reuse them during the POST. However, some servers may allow a client to get the list of refs from receive-pack without authentication, and then require authentication when the client actually tries to POST the pack. This is not ideal, as the client may do a non-trivial amount of work to generate the pack (e.g., delta-compressing objects). However, for a long time it has been the recommended example configuration in git-http-backend(1) for setting up a repository with anonymous fetch and authenticated push. This setup has always been broken without putting a username into the URL. Prior to commit 986bbc0, it did work with a username in the URL, because git would prompt for credentials before making any requests at all. However, post-986bbc0, it is totally broken. Since it has been advertised in the manpage for some time, we should make sure it works. Unfortunately, it is not as easy as simply calling post_rpc again when it fails, due to the input issue mentioned above. However, we can still make this specific case work by retrying in two specific instances: 1. If the request is large (bigger than LARGE_PACKET_MAX), we will first send a probe request with a single flush packet. Since this request is static, we can freely retry it. 2. If the request is small and we are not using gzip, then we have the whole thing in-core, and we can freely retry. That means we will not retry in some instances, including: 1. If we are using gzip. However, we only do so when calling git-upload-pack, so it does not apply to pushes. 2. If we have a large request, the probe succeeds, but then the real POST wants authentication. This is an extremely unlikely configuration and not worth worrying about. While it might be nice to cover those instances, doing so would be significantly more complex for very little real-world gain. In the long run, we will be much better off when curl learns to internally handle authentication as a callback, and we can cleanly handle all cases that way. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-08-27 17:27:15 +04:00
do {
err = probe_rpc(rpc);
http: hoist credential request out of handle_curl_result When we are handling a curl response code in http_request or in the remote-curl RPC code, we use the handle_curl_result helper to translate curl's response into an easy-to-use code. When we see an HTTP 401, we do one of two things: 1. If we already had a filled-in credential, we mark it as rejected, and then return HTTP_NOAUTH to indicate to the caller that we failed. 2. If we didn't, then we ask for a new credential and tell the caller HTTP_REAUTH to indicate that they may want to try again. Rejecting in the first case makes sense; it is the natural result of the request we just made. However, prompting for more credentials in the second step does not always make sense. We do not know for sure that the caller is going to make a second request, and nor are we sure that it will be to the same URL. Logically, the prompt belongs not to the request we just finished, but to the request we are (maybe) about to make. In practice, it is very hard to trigger any bad behavior. Currently, if we make a second request, it will always be to the same URL (even in the face of redirects, because curl handles the redirects internally). And we almost always retry on HTTP_REAUTH these days. The one exception is if we are streaming a large RPC request to the server (e.g., a pushed packfile), in which case we cannot restart. It's extremely unlikely to see a 401 response at this stage, though, as we would typically have seen it when we sent a probe request, before streaming the data. This patch drops the automatic prompt out of case 2, and instead requires the caller to do it. This is a few extra lines of code, and the bug it fixes is unlikely to come up in practice. But it is conceptually cleaner, and paves the way for better handling of credentials across redirects. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2013-09-28 12:31:45 +04:00
if (err == HTTP_REAUTH)
credential_fill(&http_auth);
http: prompt for credentials on failed POST All of the smart-http GET requests go through the http_get_* functions, which will prompt for credentials and retry if we see an HTTP 401. POST requests, however, do not go through any central point. Moreover, it is difficult to retry in the general case; we cannot assume the request body fits in memory or is even seekable, and we don't know how much of it was consumed during the attempt. Most of the time, this is not a big deal; for both fetching and pushing, we make a GET request before doing any POSTs, so typically we figure out the credentials during the first request, then reuse them during the POST. However, some servers may allow a client to get the list of refs from receive-pack without authentication, and then require authentication when the client actually tries to POST the pack. This is not ideal, as the client may do a non-trivial amount of work to generate the pack (e.g., delta-compressing objects). However, for a long time it has been the recommended example configuration in git-http-backend(1) for setting up a repository with anonymous fetch and authenticated push. This setup has always been broken without putting a username into the URL. Prior to commit 986bbc0, it did work with a username in the URL, because git would prompt for credentials before making any requests at all. However, post-986bbc0, it is totally broken. Since it has been advertised in the manpage for some time, we should make sure it works. Unfortunately, it is not as easy as simply calling post_rpc again when it fails, due to the input issue mentioned above. However, we can still make this specific case work by retrying in two specific instances: 1. If the request is large (bigger than LARGE_PACKET_MAX), we will first send a probe request with a single flush packet. Since this request is static, we can freely retry it. 2. If the request is small and we are not using gzip, then we have the whole thing in-core, and we can freely retry. That means we will not retry in some instances, including: 1. If we are using gzip. However, we only do so when calling git-upload-pack, so it does not apply to pushes. 2. If we have a large request, the probe succeeds, but then the real POST wants authentication. This is an extremely unlikely configuration and not worth worrying about. While it might be nice to cover those instances, doing so would be significantly more complex for very little real-world gain. In the long run, we will be much better off when curl learns to internally handle authentication as a callback, and we can cleanly handle all cases that way. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-08-27 17:27:15 +04:00
} while (err == HTTP_REAUTH);
if (err != HTTP_OK)
return -1;
}
headers = curl_slist_append(headers, rpc->hdr_content_type);
headers = curl_slist_append(headers, rpc->hdr_accept);
headers = curl_slist_append(headers, "Expect:");
retry:
slot = get_active_slot();
curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
curl_easy_setopt(slot->curl, CURLOPT_POST, 1);
curl_easy_setopt(slot->curl, CURLOPT_URL, rpc->service_url);
curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "gzip");
if (large_request) {
/* The request body is large and the size cannot be predicted.
* We must use chunked encoding to send it.
*/
headers = curl_slist_append(headers, "Transfer-Encoding: chunked");
rpc->initial_buffer = 1;
curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, rpc_out);
curl_easy_setopt(slot->curl, CURLOPT_INFILE, rpc);
#ifndef NO_CURL_IOCTL
curl_easy_setopt(slot->curl, CURLOPT_IOCTLFUNCTION, rpc_ioctl);
curl_easy_setopt(slot->curl, CURLOPT_IOCTLDATA, rpc);
#endif
if (options.verbosity > 1) {
fprintf(stderr, "POST %s (chunked)\n", rpc->service_name);
fflush(stderr);
}
} else if (gzip_body) {
/*
* If we are looping to retry authentication, then the previous
* run will have set up the headers and gzip buffer already,
* and we just need to send it.
*/
curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, gzip_body);
curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDSIZE, gzip_size);
} else if (use_gzip && 1024 < rpc->len) {
/* The client backend isn't giving us compressed data so
* we can try to deflate it ourselves, this may save on.
* the transfer time.
*/
2011-06-10 22:52:15 +04:00
git_zstream stream;
int ret;
memset(&stream, 0, sizeof(stream));
git_deflate_init_gzip(&stream, Z_BEST_COMPRESSION);
gzip_size = git_deflate_bound(&stream, rpc->len);
gzip_body = xmalloc(gzip_size);
stream.next_in = (unsigned char *)rpc->buf;
stream.avail_in = rpc->len;
stream.next_out = (unsigned char *)gzip_body;
stream.avail_out = gzip_size;
ret = git_deflate(&stream, Z_FINISH);
if (ret != Z_STREAM_END)
die("cannot deflate request; zlib deflate error %d", ret);
ret = git_deflate_end_gently(&stream);
if (ret != Z_OK)
die("cannot deflate request; zlib end error %d", ret);
gzip_size = stream.total_out;
headers = curl_slist_append(headers, "Content-Encoding: gzip");
curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, gzip_body);
curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDSIZE, gzip_size);
if (options.verbosity > 1) {
fprintf(stderr, "POST %s (gzip %lu to %lu bytes)\n",
rpc->service_name,
(unsigned long)rpc->len, (unsigned long)gzip_size);
fflush(stderr);
}
} else {
/* We know the complete request size in advance, use the
* more normal Content-Length approach.
*/
curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, rpc->buf);
curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDSIZE, rpc->len);
if (options.verbosity > 1) {
fprintf(stderr, "POST %s (%lu bytes)\n",
rpc->service_name, (unsigned long)rpc->len);
fflush(stderr);
}
}
curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, rpc_in);
curl_easy_setopt(slot->curl, CURLOPT_FILE, rpc);
err = run_slot(slot);
http: hoist credential request out of handle_curl_result When we are handling a curl response code in http_request or in the remote-curl RPC code, we use the handle_curl_result helper to translate curl's response into an easy-to-use code. When we see an HTTP 401, we do one of two things: 1. If we already had a filled-in credential, we mark it as rejected, and then return HTTP_NOAUTH to indicate to the caller that we failed. 2. If we didn't, then we ask for a new credential and tell the caller HTTP_REAUTH to indicate that they may want to try again. Rejecting in the first case makes sense; it is the natural result of the request we just made. However, prompting for more credentials in the second step does not always make sense. We do not know for sure that the caller is going to make a second request, and nor are we sure that it will be to the same URL. Logically, the prompt belongs not to the request we just finished, but to the request we are (maybe) about to make. In practice, it is very hard to trigger any bad behavior. Currently, if we make a second request, it will always be to the same URL (even in the face of redirects, because curl handles the redirects internally). And we almost always retry on HTTP_REAUTH these days. The one exception is if we are streaming a large RPC request to the server (e.g., a pushed packfile), in which case we cannot restart. It's extremely unlikely to see a 401 response at this stage, though, as we would typically have seen it when we sent a probe request, before streaming the data. This patch drops the automatic prompt out of case 2, and instead requires the caller to do it. This is a few extra lines of code, and the bug it fixes is unlikely to come up in practice. But it is conceptually cleaner, and paves the way for better handling of credentials across redirects. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2013-09-28 12:31:45 +04:00
if (err == HTTP_REAUTH && !large_request) {
credential_fill(&http_auth);
goto retry;
http: hoist credential request out of handle_curl_result When we are handling a curl response code in http_request or in the remote-curl RPC code, we use the handle_curl_result helper to translate curl's response into an easy-to-use code. When we see an HTTP 401, we do one of two things: 1. If we already had a filled-in credential, we mark it as rejected, and then return HTTP_NOAUTH to indicate to the caller that we failed. 2. If we didn't, then we ask for a new credential and tell the caller HTTP_REAUTH to indicate that they may want to try again. Rejecting in the first case makes sense; it is the natural result of the request we just made. However, prompting for more credentials in the second step does not always make sense. We do not know for sure that the caller is going to make a second request, and nor are we sure that it will be to the same URL. Logically, the prompt belongs not to the request we just finished, but to the request we are (maybe) about to make. In practice, it is very hard to trigger any bad behavior. Currently, if we make a second request, it will always be to the same URL (even in the face of redirects, because curl handles the redirects internally). And we almost always retry on HTTP_REAUTH these days. The one exception is if we are streaming a large RPC request to the server (e.g., a pushed packfile), in which case we cannot restart. It's extremely unlikely to see a 401 response at this stage, though, as we would typically have seen it when we sent a probe request, before streaming the data. This patch drops the automatic prompt out of case 2, and instead requires the caller to do it. This is a few extra lines of code, and the bug it fixes is unlikely to come up in practice. But it is conceptually cleaner, and paves the way for better handling of credentials across redirects. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2013-09-28 12:31:45 +04:00
}
http: prompt for credentials on failed POST All of the smart-http GET requests go through the http_get_* functions, which will prompt for credentials and retry if we see an HTTP 401. POST requests, however, do not go through any central point. Moreover, it is difficult to retry in the general case; we cannot assume the request body fits in memory or is even seekable, and we don't know how much of it was consumed during the attempt. Most of the time, this is not a big deal; for both fetching and pushing, we make a GET request before doing any POSTs, so typically we figure out the credentials during the first request, then reuse them during the POST. However, some servers may allow a client to get the list of refs from receive-pack without authentication, and then require authentication when the client actually tries to POST the pack. This is not ideal, as the client may do a non-trivial amount of work to generate the pack (e.g., delta-compressing objects). However, for a long time it has been the recommended example configuration in git-http-backend(1) for setting up a repository with anonymous fetch and authenticated push. This setup has always been broken without putting a username into the URL. Prior to commit 986bbc0, it did work with a username in the URL, because git would prompt for credentials before making any requests at all. However, post-986bbc0, it is totally broken. Since it has been advertised in the manpage for some time, we should make sure it works. Unfortunately, it is not as easy as simply calling post_rpc again when it fails, due to the input issue mentioned above. However, we can still make this specific case work by retrying in two specific instances: 1. If the request is large (bigger than LARGE_PACKET_MAX), we will first send a probe request with a single flush packet. Since this request is static, we can freely retry it. 2. If the request is small and we are not using gzip, then we have the whole thing in-core, and we can freely retry. That means we will not retry in some instances, including: 1. If we are using gzip. However, we only do so when calling git-upload-pack, so it does not apply to pushes. 2. If we have a large request, the probe succeeds, but then the real POST wants authentication. This is an extremely unlikely configuration and not worth worrying about. While it might be nice to cover those instances, doing so would be significantly more complex for very little real-world gain. In the long run, we will be much better off when curl learns to internally handle authentication as a callback, and we can cleanly handle all cases that way. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-08-27 17:27:15 +04:00
if (err != HTTP_OK)
err = -1;
curl_slist_free_all(headers);
free(gzip_body);
return err;
}
static int rpc_service(struct rpc_state *rpc, struct discovery *heads)
{
const char *svc = rpc->service_name;
struct strbuf buf = STRBUF_INIT;
struct strbuf *preamble = rpc->stdin_preamble;
struct child_process client;
int err = 0;
memset(&client, 0, sizeof(client));
client.in = -1;
client.out = -1;
client.git_cmd = 1;
client.argv = rpc->argv;
if (start_command(&client))
exit(1);
if (preamble)
write_or_die(client.in, preamble->buf, preamble->len);
if (heads)
write_or_die(client.in, heads->buf, heads->len);
rpc->alloc = http_post_buffer;
rpc->buf = xmalloc(rpc->alloc);
rpc->in = client.in;
rpc->out = client.out;
strbuf_init(&rpc->result, 0);
strbuf_addf(&buf, "%s%s", url.buf, svc);
rpc->service_url = strbuf_detach(&buf, NULL);
strbuf_addf(&buf, "Content-Type: application/x-%s-request", svc);
rpc->hdr_content_type = strbuf_detach(&buf, NULL);
strbuf_addf(&buf, "Accept: application/x-%s-result", svc);
rpc->hdr_accept = strbuf_detach(&buf, NULL);
while (!err) {
pkt-line: share buffer/descriptor reading implementation The packet_read function reads from a descriptor. The packet_get_line function is similar, but reads from an in-memory buffer, and uses a completely separate implementation. This patch teaches the generic packet_read function to accept either source, and we can do away with packet_get_line's implementation. There are two other differences to account for between the old and new functions. The first is that we used to read into a strbuf, but now read into a fixed size buffer. The only two callers are fine with that, and in fact it simplifies their code, since they can use the same static-buffer interface as the rest of the packet_read_line callers (and we provide a similar convenience wrapper for reading from a buffer rather than a descriptor). This is technically an externally-visible behavior change in that we used to accept arbitrary sized packets up to 65532 bytes, and now cap out at LARGE_PACKET_MAX, 65520. In practice this doesn't matter, as we use it only for parsing smart-http headers (of which there is exactly one defined, and it is small and fixed-size). And any extension headers would be breaking the protocol to go over LARGE_PACKET_MAX anyway. The other difference is that packet_get_line would return on error rather than dying. However, both callers of packet_get_line are actually improved by dying. The first caller does its own error checking, but we can drop that; as a result, we'll actually get more specific reporting about protocol breakage when packet_read dies internally. The only downside is that packet_read will not print the smart-http URL that failed, but that's not a big deal; anybody not debugging can already see the remote's URL already, and anybody debugging would want to run with GIT_CURL_VERBOSE anyway to see way more information. The second caller, which is just trying to skip past any extra smart-http headers (of which there are none defined, but which we allow to keep room for future expansion), did not error check at all. As a result, it would treat an error just like a flush packet. The resulting mess would generally cause an error later in get_remote_heads, but now we get error reporting much closer to the source of the problem. Brown-paper-bag-fixes-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-24 02:31:34 +04:00
int n = packet_read(rpc->out, NULL, NULL, rpc->buf, rpc->alloc, 0);
if (!n)
break;
rpc->pos = 0;
rpc->len = n;
err |= post_rpc(rpc);
}
close(client.in);
client.in = -1;
if (!err) {
strbuf_read(&rpc->result, client.out, 0);
} else {
char buf[4096];
for (;;)
if (xread(client.out, buf, sizeof(buf)) <= 0)
break;
}
close(client.out);
client.out = -1;
err |= finish_command(&client);
free(rpc->service_url);
free(rpc->hdr_content_type);
free(rpc->hdr_accept);
free(rpc->buf);
strbuf_release(&buf);
return err;
}
static int fetch_dumb(int nr_heads, struct ref **to_fetch)
{
struct walker *walker;
char **targets = xmalloc(nr_heads * sizeof(char*));
int ret, i;
if (options.depth)
die("dumb http transport does not support --depth");
for (i = 0; i < nr_heads; i++)
targets[i] = xstrdup(sha1_to_hex(to_fetch[i]->old_sha1));
walker = get_http_walker(url.buf);
walker->get_all = 1;
walker->get_tree = 1;
walker->get_history = 1;
walker->get_verbosely = options.verbosity >= 3;
walker->get_recover = 0;
ret = walker_fetch(walker, nr_heads, targets, NULL, NULL);
walker_free(walker);
for (i = 0; i < nr_heads; i++)
free(targets[i]);
free(targets);
return ret ? error("Fetch failed.") : 0;
}
static int fetch_git(struct discovery *heads,
int nr_heads, struct ref **to_fetch)
{
struct rpc_state rpc;
struct strbuf preamble = STRBUF_INIT;
char *depth_arg = NULL;
int argc = 0, i, err;
const char *argv[16];
argv[argc++] = "fetch-pack";
argv[argc++] = "--stateless-rpc";
argv[argc++] = "--stdin";
argv[argc++] = "--lock-pack";
if (options.followtags)
argv[argc++] = "--include-tag";
if (options.thin)
argv[argc++] = "--thin";
if (options.verbosity >= 3) {
argv[argc++] = "-v";
argv[argc++] = "-v";
}
if (options.check_self_contained_and_connected)
argv[argc++] = "--check-self-contained-and-connected";
if (!options.progress)
argv[argc++] = "--no-progress";
if (options.depth) {
struct strbuf buf = STRBUF_INIT;
strbuf_addf(&buf, "--depth=%lu", options.depth);
depth_arg = strbuf_detach(&buf, NULL);
argv[argc++] = depth_arg;
}
argv[argc++] = url.buf;
argv[argc++] = NULL;
for (i = 0; i < nr_heads; i++) {
struct ref *ref = to_fetch[i];
if (!ref->name || !*ref->name)
die("cannot fetch by sha1 over smart http");
packet_buf_write(&preamble, "%s\n", ref->name);
}
packet_buf_flush(&preamble);
memset(&rpc, 0, sizeof(rpc));
rpc.service_name = "git-upload-pack",
rpc.argv = argv;
rpc.stdin_preamble = &preamble;
rpc.gzip_request = 1;
err = rpc_service(&rpc, heads);
if (rpc.result.len)
write_or_die(1, rpc.result.buf, rpc.result.len);
strbuf_release(&rpc.result);
strbuf_release(&preamble);
free(depth_arg);
return err;
}
static int fetch(int nr_heads, struct ref **to_fetch)
{
remote-curl: always parse incoming refs When remote-curl receives a list of refs from a server, it keeps the whole buffer intact. When we get a "list" command, we feed the result to get_remote_heads, and when we get a "fetch" or "push" command, we feed it to fetch-pack or send-pack, respectively. If the HTTP response from the server is truncated for any reason, we will get an incomplete ref advertisement. If we then feed this incomplete list to fetch-pack, one of a few things may happen: 1. If the truncation is in a packet header, fetch-pack will notice the bogus line and complain. 2. If the truncation is inside a packet, fetch-pack will keep waiting for us to send the rest of the packet, which we never will. 3. If the truncation is at a packet boundary, fetch-pack will keep waiting for us to send the next packet, which we never will. As a result, fetch-pack hangs, waiting for input. However, remote-curl believes it has sent all of the advertisement, and therefore waits for fetch-pack to speak. The two processes end up in a deadlock. We do notice the broken ref list if we feed it to get_remote_heads. So if git asks the helper to do a "list" followed by a "fetch", we are safe; we'll abort during the list operation, which parses the refs. This patch teaches remote-curl to always parse and save the incoming ref list when we read the ref advertisement from a server. That means that we will always verify and abort before even running fetch-pack (or send-pack) when reading a corrupted list, even if we do not run the "list" command explicitly. Since we save the result, in the common case of running "list" then "fetch", we do not do any extra parsing at all. In the case of just a "fetch", we do an extra round of parsing, but only once. Note also that the "fetch" case will now also initialize server_capabilities from the remote (in remote-curl; we already would do so inside fetch-pack). Doing "list+fetch" already does this. It doesn't actually matter now, but the new behavior is arguably more correct, should remote-curl ever start caring about the server's capability list. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-21 00:07:19 +04:00
struct discovery *d = discover_refs("git-upload-pack", 0);
if (d->proto_git)
return fetch_git(d, nr_heads, to_fetch);
else
return fetch_dumb(nr_heads, to_fetch);
}
static void parse_fetch(struct strbuf *buf)
{
struct ref **to_fetch = NULL;
struct ref *list_head = NULL;
struct ref **list = &list_head;
int alloc_heads = 0, nr_heads = 0;
do {
if (!prefixcmp(buf->buf, "fetch ")) {
char *p = buf->buf + strlen("fetch ");
char *name;
struct ref *ref;
unsigned char old_sha1[20];
if (strlen(p) < 40 || get_sha1_hex(p, old_sha1))
die("protocol error: expected sha/ref, got %s'", p);
if (p[40] == ' ')
name = p + 41;
else if (!p[40])
name = "";
else
die("protocol error: expected sha/ref, got %s'", p);
ref = alloc_ref(name);
hashcpy(ref->old_sha1, old_sha1);
*list = ref;
list = &ref->next;
ALLOC_GROW(to_fetch, nr_heads + 1, alloc_heads);
to_fetch[nr_heads++] = ref;
}
else
die("http transport does not support %s", buf->buf);
strbuf_reset(buf);
if (strbuf_getline(buf, stdin, '\n') == EOF)
return;
if (!*buf->buf)
break;
} while (1);
if (fetch(nr_heads, to_fetch))
exit(128); /* error already reported */
free_refs(list_head);
free(to_fetch);
printf("\n");
fflush(stdout);
strbuf_reset(buf);
}
static int push_dav(int nr_spec, char **specs)
{
const char **argv = xmalloc((10 + nr_spec) * sizeof(char*));
int argc = 0, i;
argv[argc++] = "http-push";
argv[argc++] = "--helper-status";
if (options.dry_run)
argv[argc++] = "--dry-run";
if (options.verbosity > 1)
argv[argc++] = "--verbose";
argv[argc++] = url.buf;
for (i = 0; i < nr_spec; i++)
argv[argc++] = specs[i];
argv[argc++] = NULL;
if (run_command_v_opt(argv, RUN_GIT_CMD))
die("git-%s failed", argv[0]);
free(argv);
return 0;
}
static int push_git(struct discovery *heads, int nr_spec, char **specs)
{
struct rpc_state rpc;
int i, err;
struct argv_array args;
struct string_list_item *cas_option;
argv_array_init(&args);
argv_array_pushl(&args, "send-pack", "--stateless-rpc", "--helper-status",
NULL);
if (options.thin)
argv_array_push(&args, "--thin");
if (options.dry_run)
argv_array_push(&args, "--dry-run");
if (options.verbosity == 0)
argv_array_push(&args, "--quiet");
else if (options.verbosity > 1)
argv_array_push(&args, "--verbose");
argv_array_push(&args, options.progress ? "--progress" : "--no-progress");
for_each_string_list_item(cas_option, &cas_options)
argv_array_push(&args, cas_option->string);
argv_array_push(&args, url.buf);
for (i = 0; i < nr_spec; i++)
argv_array_push(&args, specs[i]);
memset(&rpc, 0, sizeof(rpc));
rpc.service_name = "git-receive-pack",
rpc.argv = args.argv;
err = rpc_service(&rpc, heads);
if (rpc.result.len)
write_or_die(1, rpc.result.buf, rpc.result.len);
strbuf_release(&rpc.result);
argv_array_clear(&args);
return err;
}
static int push(int nr_spec, char **specs)
{
remote-curl: always parse incoming refs When remote-curl receives a list of refs from a server, it keeps the whole buffer intact. When we get a "list" command, we feed the result to get_remote_heads, and when we get a "fetch" or "push" command, we feed it to fetch-pack or send-pack, respectively. If the HTTP response from the server is truncated for any reason, we will get an incomplete ref advertisement. If we then feed this incomplete list to fetch-pack, one of a few things may happen: 1. If the truncation is in a packet header, fetch-pack will notice the bogus line and complain. 2. If the truncation is inside a packet, fetch-pack will keep waiting for us to send the rest of the packet, which we never will. 3. If the truncation is at a packet boundary, fetch-pack will keep waiting for us to send the next packet, which we never will. As a result, fetch-pack hangs, waiting for input. However, remote-curl believes it has sent all of the advertisement, and therefore waits for fetch-pack to speak. The two processes end up in a deadlock. We do notice the broken ref list if we feed it to get_remote_heads. So if git asks the helper to do a "list" followed by a "fetch", we are safe; we'll abort during the list operation, which parses the refs. This patch teaches remote-curl to always parse and save the incoming ref list when we read the ref advertisement from a server. That means that we will always verify and abort before even running fetch-pack (or send-pack) when reading a corrupted list, even if we do not run the "list" command explicitly. Since we save the result, in the common case of running "list" then "fetch", we do not do any extra parsing at all. In the case of just a "fetch", we do an extra round of parsing, but only once. Note also that the "fetch" case will now also initialize server_capabilities from the remote (in remote-curl; we already would do so inside fetch-pack). Doing "list+fetch" already does this. It doesn't actually matter now, but the new behavior is arguably more correct, should remote-curl ever start caring about the server's capability list. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-21 00:07:19 +04:00
struct discovery *heads = discover_refs("git-receive-pack", 1);
int ret;
if (heads->proto_git)
ret = push_git(heads, nr_spec, specs);
else
ret = push_dav(nr_spec, specs);
free_discovery(heads);
return ret;
}
static void parse_push(struct strbuf *buf)
{
char **specs = NULL;
int alloc_spec = 0, nr_spec = 0, i, ret;
do {
if (!prefixcmp(buf->buf, "push ")) {
ALLOC_GROW(specs, nr_spec + 1, alloc_spec);
specs[nr_spec++] = xstrdup(buf->buf + 5);
}
else
die("http transport does not support %s", buf->buf);
strbuf_reset(buf);
if (strbuf_getline(buf, stdin, '\n') == EOF)
goto free_specs;
if (!*buf->buf)
break;
} while (1);
ret = push(nr_spec, specs);
printf("\n");
fflush(stdout);
if (ret)
exit(128); /* error already reported */
free_specs:
for (i = 0; i < nr_spec; i++)
free(specs[i]);
free(specs);
}
int main(int argc, const char **argv)
{
struct strbuf buf = STRBUF_INIT;
int nongit;
git_extract_argv0_path(argv[0]);
setup_git_directory_gently(&nongit);
if (argc < 2) {
fprintf(stderr, "Remote needed\n");
return 1;
}
options.verbosity = 1;
options.progress = !!isatty(2);
options.thin = 1;
remote = remote_get(argv[1]);
if (argc > 2) {
end_url_with_slash(&url, argv[2]);
} else {
end_url_with_slash(&url, remote->url[0]);
}
http_init(remote, url.buf, 0);
do {
if (strbuf_getline(&buf, stdin, '\n') == EOF) {
if (ferror(stdin))
fprintf(stderr, "Error reading command stream\n");
else
fprintf(stderr, "Unexpected end of command stream\n");
return 1;
}
if (buf.len == 0)
break;
if (!prefixcmp(buf.buf, "fetch ")) {
if (nongit)
die("Fetch attempted without a local repo");
parse_fetch(&buf);
} else if (!strcmp(buf.buf, "list") || !prefixcmp(buf.buf, "list ")) {
int for_push = !!strstr(buf.buf + 4, "for-push");
output_refs(get_refs(for_push));
} else if (!prefixcmp(buf.buf, "push ")) {
parse_push(&buf);
} else if (!prefixcmp(buf.buf, "option ")) {
char *name = buf.buf + strlen("option ");
char *value = strchr(name, ' ');
int result;
if (value)
*value++ = '\0';
else
value = "true";
result = set_option(name, value);
if (!result)
printf("ok\n");
else if (result < 0)
printf("error invalid value\n");
else
printf("unsupported\n");
fflush(stdout);
} else if (!strcmp(buf.buf, "capabilities")) {
printf("fetch\n");
printf("option\n");
printf("push\n");
printf("check-connectivity\n");
printf("\n");
fflush(stdout);
} else {
fprintf(stderr, "Unknown command '%s'\n", buf.buf);
return 1;
}
strbuf_reset(&buf);
} while (1);
http_cleanup();
return 0;
}