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putty/sftp.c

1448 строки
34 KiB
C
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/*
* sftp.c: SFTP generic client code.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <limits.h>
#include "misc.h"
#include "int64.h"
#include "tree234.h"
#include "sftp.h"
struct sftp_packet {
char *data;
unsigned length, maxlen;
unsigned savedpos;
int type;
};
static const char *fxp_error_message;
static int fxp_errtype;
static void fxp_internal_error(const char *msg);
/* ----------------------------------------------------------------------
* SFTP packet construction functions.
*/
static void sftp_pkt_ensure(struct sftp_packet *pkt, int length)
{
if ((int)pkt->maxlen < length) {
pkt->maxlen = length + 256;
pkt->data = sresize(pkt->data, pkt->maxlen, char);
}
}
static void sftp_pkt_adddata(struct sftp_packet *pkt,
const void *data, int len)
{
pkt->length += len;
sftp_pkt_ensure(pkt, pkt->length);
memcpy(pkt->data + pkt->length - len, data, len);
}
static void sftp_pkt_addbyte(struct sftp_packet *pkt, unsigned char byte)
{
sftp_pkt_adddata(pkt, &byte, 1);
}
static void sftp_pkt_adduint32(struct sftp_packet *pkt,
unsigned long value)
{
unsigned char x[4];
PUT_32BIT(x, value);
sftp_pkt_adddata(pkt, x, 4);
}
static struct sftp_packet *sftp_pkt_init(int pkt_type)
{
struct sftp_packet *pkt;
pkt = snew(struct sftp_packet);
pkt->data = NULL;
pkt->savedpos = -1;
pkt->length = 0;
pkt->maxlen = 0;
sftp_pkt_adduint32(pkt, 0); /* length field will be filled in later */
sftp_pkt_addbyte(pkt, (unsigned char) pkt_type);
return pkt;
}
/*
static void sftp_pkt_addbool(struct sftp_packet *pkt, unsigned char value)
{
sftp_pkt_adddata(pkt, &value, 1);
}
*/
static void sftp_pkt_adduint64(struct sftp_packet *pkt, uint64 value)
{
unsigned char x[8];
PUT_32BIT(x, value.hi);
PUT_32BIT(x + 4, value.lo);
sftp_pkt_adddata(pkt, x, 8);
}
static void sftp_pkt_addstring_start(struct sftp_packet *pkt)
{
sftp_pkt_adduint32(pkt, 0);
pkt->savedpos = pkt->length;
}
static void sftp_pkt_addstring_str(struct sftp_packet *pkt, const char *data)
{
sftp_pkt_adddata(pkt, data, strlen(data));
PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
}
static void sftp_pkt_addstring_data(struct sftp_packet *pkt,
const char *data, int len)
{
sftp_pkt_adddata(pkt, data, len);
PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
}
static void sftp_pkt_addstring(struct sftp_packet *pkt, const char *data)
{
sftp_pkt_addstring_start(pkt);
sftp_pkt_addstring_str(pkt, data);
}
static void sftp_pkt_addattrs(struct sftp_packet *pkt, struct fxp_attrs attrs)
{
sftp_pkt_adduint32(pkt, attrs.flags);
if (attrs.flags & SSH_FILEXFER_ATTR_SIZE) {
sftp_pkt_adduint32(pkt, attrs.size.hi);
sftp_pkt_adduint32(pkt, attrs.size.lo);
}
if (attrs.flags & SSH_FILEXFER_ATTR_UIDGID) {
sftp_pkt_adduint32(pkt, attrs.uid);
sftp_pkt_adduint32(pkt, attrs.gid);
}
if (attrs.flags & SSH_FILEXFER_ATTR_PERMISSIONS) {
sftp_pkt_adduint32(pkt, attrs.permissions);
}
if (attrs.flags & SSH_FILEXFER_ATTR_ACMODTIME) {
sftp_pkt_adduint32(pkt, attrs.atime);
sftp_pkt_adduint32(pkt, attrs.mtime);
}
if (attrs.flags & SSH_FILEXFER_ATTR_EXTENDED) {
/*
* We currently don't support sending any extended
* attributes.
*/
}
}
/* ----------------------------------------------------------------------
* SFTP packet decode functions.
*/
static int sftp_pkt_getbyte(struct sftp_packet *pkt, unsigned char *ret)
{
if (pkt->length - pkt->savedpos < 1)
return 0;
*ret = (unsigned char) pkt->data[pkt->savedpos];
pkt->savedpos++;
return 1;
}
static int sftp_pkt_getuint32(struct sftp_packet *pkt, unsigned long *ret)
{
if (pkt->length - pkt->savedpos < 4)
return 0;
*ret = GET_32BIT(pkt->data + pkt->savedpos);
pkt->savedpos += 4;
return 1;
}
static int sftp_pkt_getstring(struct sftp_packet *pkt,
char **p, int *length)
{
*p = NULL;
if (pkt->length - pkt->savedpos < 4)
return 0;
*length = toint(GET_32BIT(pkt->data + pkt->savedpos));
pkt->savedpos += 4;
if ((int)(pkt->length - pkt->savedpos) < *length || *length < 0) {
*length = 0;
return 0;
}
*p = pkt->data + pkt->savedpos;
pkt->savedpos += *length;
return 1;
}
static int sftp_pkt_getattrs(struct sftp_packet *pkt, struct fxp_attrs *ret)
{
if (!sftp_pkt_getuint32(pkt, &ret->flags))
return 0;
if (ret->flags & SSH_FILEXFER_ATTR_SIZE) {
unsigned long hi, lo;
if (!sftp_pkt_getuint32(pkt, &hi) ||
!sftp_pkt_getuint32(pkt, &lo))
return 0;
ret->size = uint64_make(hi, lo);
}
if (ret->flags & SSH_FILEXFER_ATTR_UIDGID) {
if (!sftp_pkt_getuint32(pkt, &ret->uid) ||
!sftp_pkt_getuint32(pkt, &ret->gid))
return 0;
}
if (ret->flags & SSH_FILEXFER_ATTR_PERMISSIONS) {
if (!sftp_pkt_getuint32(pkt, &ret->permissions))
return 0;
}
if (ret->flags & SSH_FILEXFER_ATTR_ACMODTIME) {
if (!sftp_pkt_getuint32(pkt, &ret->atime) ||
!sftp_pkt_getuint32(pkt, &ret->mtime))
return 0;
}
if (ret->flags & SSH_FILEXFER_ATTR_EXTENDED) {
unsigned long count;
if (!sftp_pkt_getuint32(pkt, &count))
return 0;
while (count--) {
char *str;
int len;
/*
* We should try to analyse these, if we ever find one
* we recognise.
*/
if (!sftp_pkt_getstring(pkt, &str, &len) ||
!sftp_pkt_getstring(pkt, &str, &len))
return 0;
}
}
return 1;
}
static void sftp_pkt_free(struct sftp_packet *pkt)
{
if (pkt->data)
sfree(pkt->data);
sfree(pkt);
}
/* ----------------------------------------------------------------------
* Send and receive packet functions.
*/
int sftp_send(struct sftp_packet *pkt)
{
int ret;
PUT_32BIT(pkt->data, pkt->length - 4);
ret = sftp_senddata(pkt->data, pkt->length);
sftp_pkt_free(pkt);
return ret;
}
struct sftp_packet *sftp_recv(void)
{
struct sftp_packet *pkt;
char x[4];
unsigned char uc;
if (!sftp_recvdata(x, 4))
return NULL;
pkt = snew(struct sftp_packet);
pkt->savedpos = 0;
pkt->length = pkt->maxlen = GET_32BIT(x);
pkt->data = snewn(pkt->length, char);
if (!sftp_recvdata(pkt->data, pkt->length)) {
sftp_pkt_free(pkt);
return NULL;
}
if (!sftp_pkt_getbyte(pkt, &uc)) {
sftp_pkt_free(pkt);
return NULL;
} else {
pkt->type = uc;
}
return pkt;
}
/* ----------------------------------------------------------------------
* Request ID allocation and temporary dispatch routines.
*/
#define REQUEST_ID_OFFSET 256
struct sftp_request {
unsigned id;
int registered;
void *userdata;
};
static int sftp_reqcmp(void *av, void *bv)
{
struct sftp_request *a = (struct sftp_request *)av;
struct sftp_request *b = (struct sftp_request *)bv;
if (a->id < b->id)
return -1;
if (a->id > b->id)
return +1;
return 0;
}
static int sftp_reqfind(void *av, void *bv)
{
unsigned *a = (unsigned *) av;
struct sftp_request *b = (struct sftp_request *)bv;
if (*a < b->id)
return -1;
if (*a > b->id)
return +1;
return 0;
}
static tree234 *sftp_requests;
static struct sftp_request *sftp_alloc_request(void)
{
unsigned low, high, mid;
int tsize;
struct sftp_request *r;
if (sftp_requests == NULL)
sftp_requests = newtree234(sftp_reqcmp);
/*
* First-fit allocation of request IDs: always pick the lowest
* unused one. To do this, binary-search using the counted
* B-tree to find the largest ID which is in a contiguous
* sequence from the beginning. (Precisely everything in that
* sequence must have ID equal to its tree index plus
* REQUEST_ID_OFFSET.)
*/
tsize = count234(sftp_requests);
low = -1;
high = tsize;
while (high - low > 1) {
mid = (high + low) / 2;
r = index234(sftp_requests, mid);
if (r->id == mid + REQUEST_ID_OFFSET)
low = mid; /* this one is fine */
else
high = mid; /* this one is past it */
}
/*
* Now low points to either -1, or the tree index of the
* largest ID in the initial sequence.
*/
{
unsigned i = low + 1 + REQUEST_ID_OFFSET;
assert(NULL == find234(sftp_requests, &i, sftp_reqfind));
}
/*
* So the request ID we need to create is
* low + 1 + REQUEST_ID_OFFSET.
*/
r = snew(struct sftp_request);
r->id = low + 1 + REQUEST_ID_OFFSET;
r->registered = 0;
r->userdata = NULL;
add234(sftp_requests, r);
return r;
}
void sftp_cleanup_request(void)
{
if (sftp_requests != NULL) {
freetree234(sftp_requests);
sftp_requests = NULL;
}
}
void sftp_register(struct sftp_request *req)
{
req->registered = 1;
}
struct sftp_request *sftp_find_request(struct sftp_packet *pktin)
{
unsigned long id;
unsigned fid;
struct sftp_request *req;
if (!pktin) {
fxp_internal_error("did not receive a valid SFTP packet\n");
return NULL;
}
if (!sftp_pkt_getuint32(pktin, &id)) {
fxp_internal_error("did not receive a valid SFTP packet\n");
return NULL;
}
fid = (unsigned)id;
req = find234(sftp_requests, &fid, sftp_reqfind);
if (!req || !req->registered) {
fxp_internal_error("request ID mismatch\n");
return NULL;
}
del234(sftp_requests, req);
return req;
}
/* ----------------------------------------------------------------------
* String handling routines.
*/
static char *mkstr(char *s, int len)
{
char *p = snewn(len + 1, char);
memcpy(p, s, len);
p[len] = '\0';
return p;
}
/* ----------------------------------------------------------------------
* SFTP primitives.
*/
/*
* Deal with (and free) an FXP_STATUS packet. Return 1 if
* SSH_FX_OK, 0 if SSH_FX_EOF, and -1 for anything else (error).
* Also place the status into fxp_errtype.
*/
static int fxp_got_status(struct sftp_packet *pktin)
{
static const char *const messages[] = {
/* SSH_FX_OK. The only time we will display a _message_ for this
* is if we were expecting something other than FXP_STATUS on
* success, so this is actually an error message! */
"unexpected OK response",
"end of file",
"no such file or directory",
"permission denied",
"failure",
"bad message",
"no connection",
"connection lost",
"operation unsupported",
};
if (pktin->type != SSH_FXP_STATUS) {
fxp_error_message = "expected FXP_STATUS packet";
fxp_errtype = -1;
} else {
unsigned long ul;
if (!sftp_pkt_getuint32(pktin, &ul)) {
fxp_error_message = "malformed FXP_STATUS packet";
fxp_errtype = -1;
} else {
fxp_errtype = ul;
if (fxp_errtype < 0 ||
fxp_errtype >= sizeof(messages) / sizeof(*messages))
fxp_error_message = "unknown error code";
else
fxp_error_message = messages[fxp_errtype];
}
}
if (fxp_errtype == SSH_FX_OK)
return 1;
else if (fxp_errtype == SSH_FX_EOF)
return 0;
else
return -1;
}
static void fxp_internal_error(const char *msg)
{
fxp_error_message = msg;
fxp_errtype = -1;
}
const char *fxp_error(void)
{
return fxp_error_message;
}
int fxp_error_type(void)
{
return fxp_errtype;
}
/*
* Perform exchange of init/version packets. Return 0 on failure.
*/
int fxp_init(void)
{
struct sftp_packet *pktout, *pktin;
unsigned long remotever;
pktout = sftp_pkt_init(SSH_FXP_INIT);
sftp_pkt_adduint32(pktout, SFTP_PROTO_VERSION);
sftp_send(pktout);
pktin = sftp_recv();
if (!pktin) {
fxp_internal_error("could not connect");
return 0;
}
if (pktin->type != SSH_FXP_VERSION) {
fxp_internal_error("did not receive FXP_VERSION");
sftp_pkt_free(pktin);
return 0;
}
if (!sftp_pkt_getuint32(pktin, &remotever)) {
fxp_internal_error("malformed FXP_VERSION packet");
sftp_pkt_free(pktin);
return 0;
}
if (remotever > SFTP_PROTO_VERSION) {
fxp_internal_error
("remote protocol is more advanced than we support");
sftp_pkt_free(pktin);
return 0;
}
/*
* In principle, this packet might also contain extension-
* string pairs. We should work through them and look for any
* we recognise. In practice we don't currently do so because
* we know we don't recognise _any_.
*/
sftp_pkt_free(pktin);
return 1;
}
/*
* Canonify a pathname.
*/
struct sftp_request *fxp_realpath_send(const char *path)
{
struct sftp_request *req = sftp_alloc_request();
struct sftp_packet *pktout;
pktout = sftp_pkt_init(SSH_FXP_REALPATH);
sftp_pkt_adduint32(pktout, req->id);
sftp_pkt_addstring_start(pktout);
sftp_pkt_addstring_str(pktout, path);
sftp_send(pktout);
return req;
}
char *fxp_realpath_recv(struct sftp_packet *pktin, struct sftp_request *req)
{
sfree(req);
if (pktin->type == SSH_FXP_NAME) {
unsigned long count;
char *path;
int len;
if (!sftp_pkt_getuint32(pktin, &count) || count != 1) {
fxp_internal_error("REALPATH did not return name count of 1\n");
sftp_pkt_free(pktin);
return NULL;
}
if (!sftp_pkt_getstring(pktin, &path, &len)) {
fxp_internal_error("REALPATH returned malformed FXP_NAME\n");
sftp_pkt_free(pktin);
return NULL;
}
path = mkstr(path, len);
sftp_pkt_free(pktin);
return path;
} else {
fxp_got_status(pktin);
sftp_pkt_free(pktin);
return NULL;
}
}
/*
* Open a file.
*/
struct sftp_request *fxp_open_send(const char *path, int type,
struct fxp_attrs *attrs)
{
struct sftp_request *req = sftp_alloc_request();
struct sftp_packet *pktout;
pktout = sftp_pkt_init(SSH_FXP_OPEN);
sftp_pkt_adduint32(pktout, req->id);
sftp_pkt_addstring(pktout, path);
sftp_pkt_adduint32(pktout, type);
if (attrs)
sftp_pkt_addattrs(pktout, *attrs);
else
sftp_pkt_adduint32(pktout, 0); /* empty ATTRS structure */
sftp_send(pktout);
return req;
}
struct fxp_handle *fxp_open_recv(struct sftp_packet *pktin,
struct sftp_request *req)
{
sfree(req);
if (pktin->type == SSH_FXP_HANDLE) {
char *hstring;
struct fxp_handle *handle;
int len;
if (!sftp_pkt_getstring(pktin, &hstring, &len)) {
fxp_internal_error("OPEN returned malformed FXP_HANDLE\n");
sftp_pkt_free(pktin);
return NULL;
}
handle = snew(struct fxp_handle);
handle->hstring = mkstr(hstring, len);
handle->hlen = len;
sftp_pkt_free(pktin);
return handle;
} else {
fxp_got_status(pktin);
sftp_pkt_free(pktin);
return NULL;
}
}
/*
* Open a directory.
*/
struct sftp_request *fxp_opendir_send(const char *path)
{
struct sftp_request *req = sftp_alloc_request();
struct sftp_packet *pktout;
pktout = sftp_pkt_init(SSH_FXP_OPENDIR);
sftp_pkt_adduint32(pktout, req->id);
sftp_pkt_addstring(pktout, path);
sftp_send(pktout);
return req;
}
struct fxp_handle *fxp_opendir_recv(struct sftp_packet *pktin,
struct sftp_request *req)
{
sfree(req);
if (pktin->type == SSH_FXP_HANDLE) {
char *hstring;
struct fxp_handle *handle;
int len;
if (!sftp_pkt_getstring(pktin, &hstring, &len)) {
fxp_internal_error("OPENDIR returned malformed FXP_HANDLE\n");
sftp_pkt_free(pktin);
return NULL;
}
handle = snew(struct fxp_handle);
handle->hstring = mkstr(hstring, len);
handle->hlen = len;
sftp_pkt_free(pktin);
return handle;
} else {
fxp_got_status(pktin);
sftp_pkt_free(pktin);
return NULL;
}
}
/*
* Close a file/dir.
*/
struct sftp_request *fxp_close_send(struct fxp_handle *handle)
{
struct sftp_request *req = sftp_alloc_request();
struct sftp_packet *pktout;
pktout = sftp_pkt_init(SSH_FXP_CLOSE);
sftp_pkt_adduint32(pktout, req->id);
sftp_pkt_addstring_start(pktout);
sftp_pkt_addstring_data(pktout, handle->hstring, handle->hlen);
sftp_send(pktout);
sfree(handle->hstring);
sfree(handle);
return req;
}
int fxp_close_recv(struct sftp_packet *pktin, struct sftp_request *req)
{
sfree(req);
fxp_got_status(pktin);
sftp_pkt_free(pktin);
return fxp_errtype == SSH_FX_OK;
}
struct sftp_request *fxp_mkdir_send(const char *path)
{
struct sftp_request *req = sftp_alloc_request();
struct sftp_packet *pktout;
pktout = sftp_pkt_init(SSH_FXP_MKDIR);
sftp_pkt_adduint32(pktout, req->id);
sftp_pkt_addstring(pktout, path);
sftp_pkt_adduint32(pktout, 0); /* (FIXME) empty ATTRS structure */
sftp_send(pktout);
return req;
}
int fxp_mkdir_recv(struct sftp_packet *pktin, struct sftp_request *req)
{
int id;
sfree(req);
id = fxp_got_status(pktin);
sftp_pkt_free(pktin);
if (id != 1) {
return 0;
}
return 1;
}
struct sftp_request *fxp_rmdir_send(const char *path)
{
struct sftp_request *req = sftp_alloc_request();
struct sftp_packet *pktout;
pktout = sftp_pkt_init(SSH_FXP_RMDIR);
sftp_pkt_adduint32(pktout, req->id);
sftp_pkt_addstring(pktout, path);
sftp_send(pktout);
return req;
}
int fxp_rmdir_recv(struct sftp_packet *pktin, struct sftp_request *req)
{
int id;
sfree(req);
id = fxp_got_status(pktin);
sftp_pkt_free(pktin);
if (id != 1) {
return 0;
}
return 1;
}
struct sftp_request *fxp_remove_send(const char *fname)
{
struct sftp_request *req = sftp_alloc_request();
struct sftp_packet *pktout;
pktout = sftp_pkt_init(SSH_FXP_REMOVE);
sftp_pkt_adduint32(pktout, req->id);
sftp_pkt_addstring(pktout, fname);
sftp_send(pktout);
return req;
}
int fxp_remove_recv(struct sftp_packet *pktin, struct sftp_request *req)
{
int id;
sfree(req);
id = fxp_got_status(pktin);
sftp_pkt_free(pktin);
if (id != 1) {
return 0;
}
return 1;
}
struct sftp_request *fxp_rename_send(const char *srcfname,
const char *dstfname)
{
struct sftp_request *req = sftp_alloc_request();
struct sftp_packet *pktout;
pktout = sftp_pkt_init(SSH_FXP_RENAME);
sftp_pkt_adduint32(pktout, req->id);
sftp_pkt_addstring(pktout, srcfname);
sftp_pkt_addstring(pktout, dstfname);
sftp_send(pktout);
return req;
}
int fxp_rename_recv(struct sftp_packet *pktin, struct sftp_request *req)
{
int id;
sfree(req);
id = fxp_got_status(pktin);
sftp_pkt_free(pktin);
if (id != 1) {
return 0;
}
return 1;
}
/*
* Retrieve the attributes of a file. We have fxp_stat which works
* on filenames, and fxp_fstat which works on open file handles.
*/
struct sftp_request *fxp_stat_send(const char *fname)
{
struct sftp_request *req = sftp_alloc_request();
struct sftp_packet *pktout;
pktout = sftp_pkt_init(SSH_FXP_STAT);
sftp_pkt_adduint32(pktout, req->id);
sftp_pkt_addstring(pktout, fname);
sftp_send(pktout);
return req;
}
int fxp_stat_recv(struct sftp_packet *pktin, struct sftp_request *req,
struct fxp_attrs *attrs)
{
sfree(req);
if (pktin->type == SSH_FXP_ATTRS) {
if (!sftp_pkt_getattrs(pktin, attrs)) {
fxp_internal_error("malformed SSH_FXP_ATTRS packet");
sftp_pkt_free(pktin);
return 0;
}
sftp_pkt_free(pktin);
return 1;
} else {
fxp_got_status(pktin);
sftp_pkt_free(pktin);
return 0;
}
}
struct sftp_request *fxp_fstat_send(struct fxp_handle *handle)
{
struct sftp_request *req = sftp_alloc_request();
struct sftp_packet *pktout;
pktout = sftp_pkt_init(SSH_FXP_FSTAT);
sftp_pkt_adduint32(pktout, req->id);
sftp_pkt_addstring_start(pktout);
sftp_pkt_addstring_data(pktout, handle->hstring, handle->hlen);
sftp_send(pktout);
return req;
}
int fxp_fstat_recv(struct sftp_packet *pktin, struct sftp_request *req,
struct fxp_attrs *attrs)
{
sfree(req);
if (pktin->type == SSH_FXP_ATTRS) {
if (!sftp_pkt_getattrs(pktin, attrs)) {
fxp_internal_error("malformed SSH_FXP_ATTRS packet");
sftp_pkt_free(pktin);
return 0;
}
sftp_pkt_free(pktin);
return 1;
} else {
fxp_got_status(pktin);
sftp_pkt_free(pktin);
return 0;
}
}
/*
* Set the attributes of a file.
*/
struct sftp_request *fxp_setstat_send(const char *fname,
struct fxp_attrs attrs)
{
struct sftp_request *req = sftp_alloc_request();
struct sftp_packet *pktout;
pktout = sftp_pkt_init(SSH_FXP_SETSTAT);
sftp_pkt_adduint32(pktout, req->id);
sftp_pkt_addstring(pktout, fname);
sftp_pkt_addattrs(pktout, attrs);
sftp_send(pktout);
return req;
}
int fxp_setstat_recv(struct sftp_packet *pktin, struct sftp_request *req)
{
int id;
sfree(req);
id = fxp_got_status(pktin);
sftp_pkt_free(pktin);
if (id != 1) {
return 0;
}
return 1;
}
struct sftp_request *fxp_fsetstat_send(struct fxp_handle *handle,
struct fxp_attrs attrs)
{
struct sftp_request *req = sftp_alloc_request();
struct sftp_packet *pktout;
pktout = sftp_pkt_init(SSH_FXP_FSETSTAT);
sftp_pkt_adduint32(pktout, req->id);
sftp_pkt_addstring_start(pktout);
sftp_pkt_addstring_data(pktout, handle->hstring, handle->hlen);
sftp_pkt_addattrs(pktout, attrs);
sftp_send(pktout);
return req;
}
int fxp_fsetstat_recv(struct sftp_packet *pktin, struct sftp_request *req)
{
int id;
sfree(req);
id = fxp_got_status(pktin);
sftp_pkt_free(pktin);
if (id != 1) {
return 0;
}
return 1;
}
/*
* Read from a file. Returns the number of bytes read, or -1 on an
* error, or possibly 0 if EOF. (I'm not entirely sure whether it
* will return 0 on EOF, or return -1 and store SSH_FX_EOF in the
* error indicator. It might even depend on the SFTP server.)
*/
struct sftp_request *fxp_read_send(struct fxp_handle *handle,
uint64 offset, int len)
{
struct sftp_request *req = sftp_alloc_request();
struct sftp_packet *pktout;
pktout = sftp_pkt_init(SSH_FXP_READ);
sftp_pkt_adduint32(pktout, req->id);
sftp_pkt_addstring_start(pktout);
sftp_pkt_addstring_data(pktout, handle->hstring, handle->hlen);
sftp_pkt_adduint64(pktout, offset);
sftp_pkt_adduint32(pktout, len);
sftp_send(pktout);
return req;
}
int fxp_read_recv(struct sftp_packet *pktin, struct sftp_request *req,
char *buffer, int len)
{
sfree(req);
if (pktin->type == SSH_FXP_DATA) {
char *str;
int rlen;
if (!sftp_pkt_getstring(pktin, &str, &rlen)) {
fxp_internal_error("READ returned malformed SSH_FXP_DATA packet");
sftp_pkt_free(pktin);
return -1;
}
if (rlen > len || rlen < 0) {
fxp_internal_error("READ returned more bytes than requested");
sftp_pkt_free(pktin);
return -1;
}
memcpy(buffer, str, rlen);
sftp_pkt_free(pktin);
return rlen;
} else {
fxp_got_status(pktin);
sftp_pkt_free(pktin);
return -1;
}
}
/*
* Read from a directory.
*/
struct sftp_request *fxp_readdir_send(struct fxp_handle *handle)
{
struct sftp_request *req = sftp_alloc_request();
struct sftp_packet *pktout;
pktout = sftp_pkt_init(SSH_FXP_READDIR);
sftp_pkt_adduint32(pktout, req->id);
sftp_pkt_addstring_start(pktout);
sftp_pkt_addstring_data(pktout, handle->hstring, handle->hlen);
sftp_send(pktout);
return req;
}
struct fxp_names *fxp_readdir_recv(struct sftp_packet *pktin,
struct sftp_request *req)
{
sfree(req);
if (pktin->type == SSH_FXP_NAME) {
struct fxp_names *ret;
unsigned long i;
/*
* Sanity-check the number of names. Minimum is obviously
* zero. Maximum is the remaining space in the packet
* divided by the very minimum length of a name, which is
* 12 bytes (4 for an empty filename, 4 for an empty
* longname, 4 for a set of attribute flags indicating that
* no other attributes are supplied).
*/
if (!sftp_pkt_getuint32(pktin, &i) ||
i > (pktin->length-pktin->savedpos)/12) {
fxp_internal_error("malformed FXP_NAME packet");
sftp_pkt_free(pktin);
return NULL;
}
/*
* Ensure the implicit multiplication in the snewn() call
* doesn't suffer integer overflow and cause us to malloc
* too little space.
*/
if (i > INT_MAX / sizeof(struct fxp_name)) {
fxp_internal_error("unreasonably large FXP_NAME packet");
sftp_pkt_free(pktin);
return NULL;
}
ret = snew(struct fxp_names);
ret->nnames = i;
ret->names = snewn(ret->nnames, struct fxp_name);
for (i = 0; i < (unsigned long)ret->nnames; i++) {
char *str1, *str2;
int len1, len2;
if (!sftp_pkt_getstring(pktin, &str1, &len1) ||
!sftp_pkt_getstring(pktin, &str2, &len2) ||
!sftp_pkt_getattrs(pktin, &ret->names[i].attrs)) {
fxp_internal_error("malformed FXP_NAME packet");
while (i--) {
sfree(ret->names[i].filename);
sfree(ret->names[i].longname);
}
sfree(ret->names);
sfree(ret);
sfree(pktin);
return NULL;
}
ret->names[i].filename = mkstr(str1, len1);
ret->names[i].longname = mkstr(str2, len2);
}
sftp_pkt_free(pktin);
return ret;
} else {
fxp_got_status(pktin);
sftp_pkt_free(pktin);
return NULL;
}
}
/*
* Write to a file. Returns 0 on error, 1 on OK.
*/
struct sftp_request *fxp_write_send(struct fxp_handle *handle,
char *buffer, uint64 offset, int len)
{
struct sftp_request *req = sftp_alloc_request();
struct sftp_packet *pktout;
pktout = sftp_pkt_init(SSH_FXP_WRITE);
sftp_pkt_adduint32(pktout, req->id);
sftp_pkt_addstring_start(pktout);
sftp_pkt_addstring_data(pktout, handle->hstring, handle->hlen);
sftp_pkt_adduint64(pktout, offset);
sftp_pkt_addstring_start(pktout);
sftp_pkt_addstring_data(pktout, buffer, len);
sftp_send(pktout);
return req;
}
int fxp_write_recv(struct sftp_packet *pktin, struct sftp_request *req)
{
sfree(req);
fxp_got_status(pktin);
sftp_pkt_free(pktin);
return fxp_errtype == SSH_FX_OK;
}
/*
* Free up an fxp_names structure.
*/
void fxp_free_names(struct fxp_names *names)
{
int i;
for (i = 0; i < names->nnames; i++) {
sfree(names->names[i].filename);
sfree(names->names[i].longname);
}
sfree(names->names);
sfree(names);
}
/*
* Duplicate an fxp_name structure.
*/
struct fxp_name *fxp_dup_name(struct fxp_name *name)
{
struct fxp_name *ret;
ret = snew(struct fxp_name);
ret->filename = dupstr(name->filename);
ret->longname = dupstr(name->longname);
ret->attrs = name->attrs; /* structure copy */
return ret;
}
/*
* Free up an fxp_name structure.
*/
void fxp_free_name(struct fxp_name *name)
{
sfree(name->filename);
sfree(name->longname);
sfree(name);
}
/*
* Store user data in an sftp_request structure.
*/
void *fxp_get_userdata(struct sftp_request *req)
{
return req->userdata;
}
void fxp_set_userdata(struct sftp_request *req, void *data)
{
req->userdata = data;
}
/*
* A wrapper to go round fxp_read_* and fxp_write_*, which manages
* the queueing of multiple read/write requests.
*/
struct req {
char *buffer;
int len, retlen, complete;
uint64 offset;
struct req *next, *prev;
};
struct fxp_xfer {
uint64 offset, furthestdata, filesize;
int req_totalsize, req_maxsize, eof, err;
struct fxp_handle *fh;
struct req *head, *tail;
};
static struct fxp_xfer *xfer_init(struct fxp_handle *fh, uint64 offset)
{
struct fxp_xfer *xfer = snew(struct fxp_xfer);
xfer->fh = fh;
xfer->offset = offset;
xfer->head = xfer->tail = NULL;
xfer->req_totalsize = 0;
xfer->req_maxsize = 1048576;
xfer->err = 0;
xfer->filesize = uint64_make(ULONG_MAX, ULONG_MAX);
xfer->furthestdata = uint64_make(0, 0);
return xfer;
}
int xfer_done(struct fxp_xfer *xfer)
{
/*
* We're finished if we've seen EOF _and_ there are no
* outstanding requests.
*/
return (xfer->eof || xfer->err) && !xfer->head;
}
void xfer_download_queue(struct fxp_xfer *xfer)
{
while (xfer->req_totalsize < xfer->req_maxsize &&
!xfer->eof && !xfer->err) {
/*
* Queue a new read request.
*/
struct req *rr;
struct sftp_request *req;
rr = snew(struct req);
rr->offset = xfer->offset;
rr->complete = 0;
if (xfer->tail) {
xfer->tail->next = rr;
rr->prev = xfer->tail;
} else {
xfer->head = rr;
rr->prev = NULL;
}
xfer->tail = rr;
rr->next = NULL;
rr->len = 32768;
rr->buffer = snewn(rr->len, char);
sftp_register(req = fxp_read_send(xfer->fh, rr->offset, rr->len));
fxp_set_userdata(req, rr);
xfer->offset = uint64_add32(xfer->offset, rr->len);
xfer->req_totalsize += rr->len;
#ifdef DEBUG_DOWNLOAD
{ char buf[40]; uint64_decimal(rr->offset, buf); printf("queueing read request %p at %s\n", rr, buf); }
#endif
}
}
struct fxp_xfer *xfer_download_init(struct fxp_handle *fh, uint64 offset)
{
struct fxp_xfer *xfer = xfer_init(fh, offset);
xfer->eof = FALSE;
xfer_download_queue(xfer);
return xfer;
}
/*
* Returns INT_MIN to indicate that it didn't even get as far as
* fxp_read_recv and hence has not freed pktin.
*/
int xfer_download_gotpkt(struct fxp_xfer *xfer, struct sftp_packet *pktin)
{
struct sftp_request *rreq;
struct req *rr;
rreq = sftp_find_request(pktin);
if (!rreq)
return INT_MIN; /* this packet doesn't even make sense */
rr = (struct req *)fxp_get_userdata(rreq);
if (!rr) {
fxp_internal_error("request ID is not part of the current download");
return INT_MIN; /* this packet isn't ours */
}
rr->retlen = fxp_read_recv(pktin, rreq, rr->buffer, rr->len);
#ifdef DEBUG_DOWNLOAD
printf("read request %p has returned [%d]\n", rr, rr->retlen);
#endif
if ((rr->retlen < 0 && fxp_error_type()==SSH_FX_EOF) || rr->retlen == 0) {
xfer->eof = TRUE;
rr->complete = -1;
#ifdef DEBUG_DOWNLOAD
printf("setting eof\n");
#endif
} else if (rr->retlen < 0) {
/* some error other than EOF; signal it back to caller */
xfer_set_error(xfer);
rr->complete = -1;
return -1;
}
rr->complete = 1;
/*
* Special case: if we have received fewer bytes than we
* actually read, we should do something. For the moment I'll
* just throw an ersatz FXP error to signal this; the SFTP
* draft I've got says that it can't happen except on special
* files, in which case seeking probably has very little
* meaning and so queueing an additional read request to fill
* up the gap sounds like the wrong answer. I'm not sure what I
* should be doing here - if it _was_ a special file, I suspect
* I simply shouldn't have been queueing multiple requests in
* the first place...
*/
if (rr->retlen > 0 && uint64_compare(xfer->furthestdata, rr->offset) < 0) {
xfer->furthestdata = rr->offset;
#ifdef DEBUG_DOWNLOAD
{ char buf[40];
uint64_decimal(xfer->furthestdata, buf);
printf("setting furthestdata = %s\n", buf); }
#endif
}
if (rr->retlen < rr->len) {
uint64 filesize = uint64_add32(rr->offset,
(rr->retlen < 0 ? 0 : rr->retlen));
#ifdef DEBUG_DOWNLOAD
{ char buf[40];
uint64_decimal(filesize, buf);
printf("short block! trying filesize = %s\n", buf); }
#endif
if (uint64_compare(xfer->filesize, filesize) > 0) {
xfer->filesize = filesize;
#ifdef DEBUG_DOWNLOAD
printf("actually changing filesize\n");
#endif
}
}
if (uint64_compare(xfer->furthestdata, xfer->filesize) > 0) {
fxp_error_message = "received a short buffer from FXP_READ, but not"
" at EOF";
fxp_errtype = -1;
xfer_set_error(xfer);
return -1;
}
return 1;
}
void xfer_set_error(struct fxp_xfer *xfer)
{
xfer->err = 1;
}
int xfer_download_data(struct fxp_xfer *xfer, void **buf, int *len)
{
void *retbuf = NULL;
int retlen = 0;
/*
* Discard anything at the head of the rr queue with complete <
* 0; return the first thing with complete > 0.
*/
while (xfer->head && xfer->head->complete && !retbuf) {
struct req *rr = xfer->head;
if (rr->complete > 0) {
retbuf = rr->buffer;
retlen = rr->retlen;
#ifdef DEBUG_DOWNLOAD
printf("handing back data from read request %p\n", rr);
#endif
}
#ifdef DEBUG_DOWNLOAD
else
printf("skipping failed read request %p\n", rr);
#endif
xfer->head = xfer->head->next;
if (xfer->head)
xfer->head->prev = NULL;
else
xfer->tail = NULL;
xfer->req_totalsize -= rr->len;
sfree(rr);
}
if (retbuf) {
*buf = retbuf;
*len = retlen;
return 1;
} else
return 0;
}
struct fxp_xfer *xfer_upload_init(struct fxp_handle *fh, uint64 offset)
{
struct fxp_xfer *xfer = xfer_init(fh, offset);
/*
* We set `eof' to 1 because this will cause xfer_done() to
* return true iff there are no outstanding requests. During an
* upload, our caller will be responsible for working out
* whether all the data has been sent, so all it needs to know
* from us is whether the outstanding requests have been
* handled once that's done.
*/
xfer->eof = 1;
return xfer;
}
int xfer_upload_ready(struct fxp_xfer *xfer)
{
if (sftp_sendbuffer() == 0)
return 1;
else
return 0;
}
void xfer_upload_data(struct fxp_xfer *xfer, char *buffer, int len)
{
struct req *rr;
struct sftp_request *req;
rr = snew(struct req);
rr->offset = xfer->offset;
rr->complete = 0;
if (xfer->tail) {
xfer->tail->next = rr;
rr->prev = xfer->tail;
} else {
xfer->head = rr;
rr->prev = NULL;
}
xfer->tail = rr;
rr->next = NULL;
rr->len = len;
rr->buffer = NULL;
sftp_register(req = fxp_write_send(xfer->fh, buffer, rr->offset, len));
fxp_set_userdata(req, rr);
xfer->offset = uint64_add32(xfer->offset, rr->len);
xfer->req_totalsize += rr->len;
#ifdef DEBUG_UPLOAD
{ char buf[40]; uint64_decimal(rr->offset, buf); printf("queueing write request %p at %s [len %d]\n", rr, buf, len); }
#endif
}
/*
* Returns INT_MIN to indicate that it didn't even get as far as
* fxp_write_recv and hence has not freed pktin.
*/
int xfer_upload_gotpkt(struct fxp_xfer *xfer, struct sftp_packet *pktin)
{
struct sftp_request *rreq;
struct req *rr, *prev, *next;
int ret;
rreq = sftp_find_request(pktin);
if (!rreq)
return INT_MIN; /* this packet doesn't even make sense */
rr = (struct req *)fxp_get_userdata(rreq);
if (!rr) {
fxp_internal_error("request ID is not part of the current upload");
return INT_MIN; /* this packet isn't ours */
}
ret = fxp_write_recv(pktin, rreq);
#ifdef DEBUG_UPLOAD
printf("write request %p has returned [%d]\n", rr, ret);
#endif
/*
* Remove this one from the queue.
*/
prev = rr->prev;
next = rr->next;
if (prev)
prev->next = next;
else
xfer->head = next;
if (next)
next->prev = prev;
else
xfer->tail = prev;
xfer->req_totalsize -= rr->len;
sfree(rr);
if (!ret)
return -1;
return 1;
}
void xfer_cleanup(struct fxp_xfer *xfer)
{
struct req *rr;
while (xfer->head) {
rr = xfer->head;
xfer->head = xfer->head->next;
sfree(rr->buffer);
sfree(rr);
}
sfree(xfer);
}
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