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putty/unix/uxnet.c

1743 строки
44 KiB
C
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/*
* Unix networking abstraction.
*/
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <netdb.h>
#include <sys/un.h>
#include <pwd.h>
#include <grp.h>
#include "putty.h"
#include "network.h"
#include "tree234.h"
/* Solaris needs <sys/sockio.h> for SIOCATMARK. */
#ifndef SIOCATMARK
#include <sys/sockio.h>
#endif
#ifndef X11_UNIX_PATH
# define X11_UNIX_PATH "/tmp/.X11-unix/X"
#endif
/*
* Access to sockaddr types without breaking C strict aliasing rules.
*/
union sockaddr_union {
struct sockaddr_storage storage;
struct sockaddr sa;
struct sockaddr_in sin;
#ifndef NO_IPV6
struct sockaddr_in6 sin6;
#endif
struct sockaddr_un su;
};
/*
* Mutable state that goes with a SockAddr: stores information
* about where in the list of candidate IP(v*) addresses we've
* currently got to.
*/
typedef struct SockAddrStep_tag SockAddrStep;
struct SockAddrStep_tag {
#ifndef NO_IPV6
struct addrinfo *ai; /* steps along addr->ais */
#endif
int curraddr;
};
typedef struct NetSocket NetSocket;
struct NetSocket {
const char *error;
int s;
Plug *plug;
bufchain output_data;
bool connected; /* irrelevant for listening sockets */
bool writable;
bool frozen; /* this causes readability notifications to be ignored */
bool localhost_only; /* for listening sockets */
char oobdata[1];
size_t sending_oob;
bool oobpending; /* is there OOB data available to read? */
bool oobinline;
enum { EOF_NO, EOF_PENDING, EOF_SENT } outgoingeof;
bool incomingeof;
int pending_error; /* in case send() returns error */
bool listener;
bool nodelay, keepalive; /* for connect()-type sockets */
bool privport;
int port; /* and again */
SockAddr *addr;
SockAddrStep step;
/*
* We sometimes need pairs of Socket structures to be linked:
* if we are listening on the same IPv6 and v4 port, for
* example. So here we define `parent' and `child' pointers to
* track this link.
*/
NetSocket *parent, *child;
Socket sock;
};
struct SockAddr {
int refcount;
const char *error;
enum { UNRESOLVED, UNIX, IP } superfamily;
#ifndef NO_IPV6
struct addrinfo *ais; /* Addresses IPv6 style. */
#else
unsigned long *addresses; /* Addresses IPv4 style. */
int naddresses;
#endif
char hostname[512]; /* Store an unresolved host name. */
};
/*
* Which address family this address belongs to. AF_INET for IPv4;
* AF_INET6 for IPv6; AF_UNSPEC indicates that name resolution has
* not been done and a simple host name is held in this SockAddr
* structure.
*/
#ifndef NO_IPV6
#define SOCKADDR_FAMILY(addr, step) \
((addr)->superfamily == UNRESOLVED ? AF_UNSPEC : \
(addr)->superfamily == UNIX ? AF_UNIX : \
(step).ai ? (step).ai->ai_family : AF_INET)
#else
/* Here we gratuitously reference 'step' to avoid gcc warnings about
* 'set but not used' when compiling -DNO_IPV6 */
#define SOCKADDR_FAMILY(addr, step) \
((addr)->superfamily == UNRESOLVED ? AF_UNSPEC : \
(addr)->superfamily == UNIX ? AF_UNIX : \
(step).curraddr ? AF_INET : AF_INET)
#endif
/*
* Start a SockAddrStep structure to step through multiple
* addresses.
*/
#ifndef NO_IPV6
#define START_STEP(addr, step) \
((step).ai = (addr)->ais, (step).curraddr = 0)
#else
#define START_STEP(addr, step) \
((step).curraddr = 0)
#endif
static tree234 *sktree;
static void uxsel_tell(NetSocket *s);
static int cmpfortree(void *av, void *bv)
{
NetSocket *a = (NetSocket *) av, *b = (NetSocket *) bv;
int as = a->s, bs = b->s;
if (as < bs)
return -1;
if (as > bs)
return +1;
if (a < b)
return -1;
if (a > b)
return +1;
return 0;
}
static int cmpforsearch(void *av, void *bv)
{
NetSocket *b = (NetSocket *) bv;
int as = *(int *)av, bs = b->s;
if (as < bs)
return -1;
if (as > bs)
return +1;
return 0;
}
void sk_init(void)
{
sktree = newtree234(cmpfortree);
}
void sk_cleanup(void)
{
NetSocket *s;
int i;
if (sktree) {
for (i = 0; (s = index234(sktree, i)) != NULL; i++) {
close(s->s);
}
}
}
SockAddr *sk_namelookup(const char *host, char **canonicalname, int address_family)
{
SockAddr *ret = snew(SockAddr);
#ifndef NO_IPV6
struct addrinfo hints;
int err;
#else
unsigned long a;
struct hostent *h = NULL;
int n;
#endif
strbuf *realhost = strbuf_new();
/* Clear the structure and default to IPv4. */
memset(ret, 0, sizeof(SockAddr));
ret->superfamily = UNRESOLVED;
ret->error = NULL;
ret->refcount = 1;
#ifndef NO_IPV6
hints.ai_flags = AI_CANONNAME;
hints.ai_family = (address_family == ADDRTYPE_IPV4 ? AF_INET :
address_family == ADDRTYPE_IPV6 ? AF_INET6 :
AF_UNSPEC);
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = 0;
hints.ai_addrlen = 0;
hints.ai_addr = NULL;
hints.ai_canonname = NULL;
hints.ai_next = NULL;
{
char *trimmed_host = host_strduptrim(host); /* strip [] on literals */
err = getaddrinfo(trimmed_host, NULL, &hints, &ret->ais);
sfree(trimmed_host);
}
if (err != 0) {
ret->error = gai_strerror(err);
return ret;
}
ret->superfamily = IP;
if (ret->ais->ai_canonname != NULL)
strbuf_catf(realhost, "%s", ret->ais->ai_canonname);
else
strbuf_catf(realhost, "%s", host);
#else
if ((a = inet_addr(host)) == (unsigned long)(in_addr_t)(-1)) {
/*
* Otherwise use the IPv4-only gethostbyname... (NOTE:
* we don't use gethostbyname as a fallback!)
*/
if (ret->superfamily == UNRESOLVED) {
/*debug("Resolving \"%s\" with gethostbyname() (IPv4 only)...\n", host); */
if ( (h = gethostbyname(host)) )
ret->superfamily = IP;
}
if (ret->superfamily == UNRESOLVED) {
ret->error = (h_errno == HOST_NOT_FOUND ||
h_errno == NO_DATA ||
h_errno == NO_ADDRESS ? "Host does not exist" :
h_errno == TRY_AGAIN ?
"Temporary name service failure" :
"gethostbyname: unknown error");
strbuf_free(realhost);
return ret;
}
/* This way we are always sure the h->h_name is valid :) */
realhost->len = 0;
strbuf_catf(realhost, "%s", h->h_name);
for (n = 0; h->h_addr_list[n]; n++);
ret->addresses = snewn(n, unsigned long);
ret->naddresses = n;
for (n = 0; n < ret->naddresses; n++) {
memcpy(&a, h->h_addr_list[n], sizeof(a));
ret->addresses[n] = ntohl(a);
}
} else {
/*
* This must be a numeric IPv4 address because it caused a
* success return from inet_addr.
*/
ret->superfamily = IP;
realhost->len = 0;
strbuf_catf(realhost, "%s", host);
ret->addresses = snew(unsigned long);
ret->naddresses = 1;
ret->addresses[0] = ntohl(a);
}
#endif
*canonicalname = strbuf_to_str(realhost);
return ret;
}
SockAddr *sk_nonamelookup(const char *host)
{
SockAddr *ret = snew(SockAddr);
ret->error = NULL;
ret->superfamily = UNRESOLVED;
strncpy(ret->hostname, host, lenof(ret->hostname));
ret->hostname[lenof(ret->hostname)-1] = '\0';
#ifndef NO_IPV6
ret->ais = NULL;
#else
ret->addresses = NULL;
#endif
ret->refcount = 1;
return ret;
}
static bool sk_nextaddr(SockAddr *addr, SockAddrStep *step)
{
#ifndef NO_IPV6
if (step->ai && step->ai->ai_next) {
step->ai = step->ai->ai_next;
return true;
} else
return false;
#else
if (step->curraddr+1 < addr->naddresses) {
step->curraddr++;
return true;
} else {
return false;
}
#endif
}
void sk_getaddr(SockAddr *addr, char *buf, int buflen)
{
if (addr->superfamily == UNRESOLVED || addr->superfamily == UNIX) {
strncpy(buf, addr->hostname, buflen);
buf[buflen-1] = '\0';
} else {
#ifndef NO_IPV6
if (getnameinfo(addr->ais->ai_addr, addr->ais->ai_addrlen, buf, buflen,
NULL, 0, NI_NUMERICHOST) != 0) {
buf[0] = '\0';
strncat(buf, "<unknown>", buflen - 1);
}
#else
struct in_addr a;
SockAddrStep step;
START_STEP(addr, step);
assert(SOCKADDR_FAMILY(addr, step) == AF_INET);
a.s_addr = htonl(addr->addresses[0]);
strncpy(buf, inet_ntoa(a), buflen);
buf[buflen-1] = '\0';
#endif
}
}
/*
* This constructs a SockAddr that points at one specific sub-address
* of a parent SockAddr. The returned SockAddr does not own all its
* own memory: it points into the old one's data structures, so it
* MUST NOT be used after the old one is freed, and it MUST NOT be
* passed to sk_addr_free. (The latter is why it's returned by value
* rather than dynamically allocated - that should clue in anyone
* writing a call to it that something is weird about it.)
*/
static SockAddr sk_extractaddr_tmp(
SockAddr *addr, const SockAddrStep *step)
{
SockAddr toret;
toret = *addr; /* structure copy */
toret.refcount = 1;
if (addr->superfamily == IP) {
#ifndef NO_IPV6
toret.ais = step->ai;
#else
assert(SOCKADDR_FAMILY(addr, *step) == AF_INET);
toret.addresses += step->curraddr;
#endif
}
return toret;
}
bool sk_addr_needs_port(SockAddr *addr)
{
if (addr->superfamily == UNRESOLVED || addr->superfamily == UNIX) {
return false;
} else {
return true;
}
}
bool sk_hostname_is_local(const char *name)
{
return !strcmp(name, "localhost") ||
!strcmp(name, "::1") ||
!strncmp(name, "127.", 4);
}
#define ipv4_is_loopback(addr) \
(((addr).s_addr & htonl(0xff000000)) == htonl(0x7f000000))
static bool sockaddr_is_loopback(struct sockaddr *sa)
{
union sockaddr_union *u = (union sockaddr_union *)sa;
switch (u->sa.sa_family) {
case AF_INET:
return ipv4_is_loopback(u->sin.sin_addr);
#ifndef NO_IPV6
case AF_INET6:
return IN6_IS_ADDR_LOOPBACK(&u->sin6.sin6_addr);
#endif
case AF_UNIX:
return true;
default:
return false;
}
}
bool sk_address_is_local(SockAddr *addr)
{
if (addr->superfamily == UNRESOLVED)
return false; /* we don't know; assume not */
else if (addr->superfamily == UNIX)
return true;
else {
#ifndef NO_IPV6
return sockaddr_is_loopback(addr->ais->ai_addr);
#else
struct in_addr a;
SockAddrStep step;
START_STEP(addr, step);
assert(SOCKADDR_FAMILY(addr, step) == AF_INET);
a.s_addr = htonl(addr->addresses[0]);
return ipv4_is_loopback(a);
#endif
}
}
bool sk_address_is_special_local(SockAddr *addr)
{
return addr->superfamily == UNIX;
}
int sk_addrtype(SockAddr *addr)
{
SockAddrStep step;
int family;
START_STEP(addr, step);
family = SOCKADDR_FAMILY(addr, step);
return (family == AF_INET ? ADDRTYPE_IPV4 :
#ifndef NO_IPV6
family == AF_INET6 ? ADDRTYPE_IPV6 :
#endif
ADDRTYPE_NAME);
}
void sk_addrcopy(SockAddr *addr, char *buf)
{
SockAddrStep step;
int family;
START_STEP(addr, step);
family = SOCKADDR_FAMILY(addr, step);
#ifndef NO_IPV6
if (family == AF_INET)
memcpy(buf, &((struct sockaddr_in *)step.ai->ai_addr)->sin_addr,
sizeof(struct in_addr));
else if (family == AF_INET6)
memcpy(buf, &((struct sockaddr_in6 *)step.ai->ai_addr)->sin6_addr,
sizeof(struct in6_addr));
else
unreachable("bad address family in sk_addrcopy");
#else
struct in_addr a;
assert(family == AF_INET);
a.s_addr = htonl(addr->addresses[step.curraddr]);
memcpy(buf, (char*) &a.s_addr, 4);
#endif
}
void sk_addr_free(SockAddr *addr)
{
if (--addr->refcount > 0)
return;
#ifndef NO_IPV6
if (addr->ais != NULL)
freeaddrinfo(addr->ais);
#else
sfree(addr->addresses);
#endif
sfree(addr);
}
SockAddr *sk_addr_dup(SockAddr *addr)
{
addr->refcount++;
return addr;
}
static Plug *sk_net_plug(Socket *sock, Plug *p)
{
NetSocket *s = container_of(sock, NetSocket, sock);
Plug *ret = s->plug;
if (p)
s->plug = p;
return ret;
}
static void sk_net_flush(Socket *s)
{
/*
* We send data to the socket as soon as we can anyway,
* so we don't need to do anything here. :-)
*/
}
static void sk_net_close(Socket *s);
static size_t sk_net_write(Socket *s, const void *data, size_t len);
static size_t sk_net_write_oob(Socket *s, const void *data, size_t len);
static void sk_net_write_eof(Socket *s);
static void sk_net_set_frozen(Socket *s, bool is_frozen);
static SocketPeerInfo *sk_net_peer_info(Socket *s);
static const char *sk_net_socket_error(Socket *s);
static struct SocketVtable NetSocket_sockvt = {
sk_net_plug,
sk_net_close,
sk_net_write,
sk_net_write_oob,
sk_net_write_eof,
sk_net_flush,
sk_net_set_frozen,
sk_net_socket_error,
sk_net_peer_info,
};
static Socket *sk_net_accept(accept_ctx_t ctx, Plug *plug)
{
int sockfd = ctx.i;
NetSocket *ret;
/*
* Create NetSocket structure.
*/
ret = snew(NetSocket);
ret->sock.vt = &NetSocket_sockvt;
ret->error = NULL;
ret->plug = plug;
bufchain_init(&ret->output_data);
ret->writable = true; /* to start with */
ret->sending_oob = 0;
ret->frozen = true;
ret->localhost_only = false; /* unused, but best init anyway */
ret->pending_error = 0;
ret->oobpending = false;
ret->outgoingeof = EOF_NO;
ret->incomingeof = false;
ret->listener = false;
ret->parent = ret->child = NULL;
ret->addr = NULL;
ret->connected = true;
ret->s = sockfd;
if (ret->s < 0) {
ret->error = strerror(errno);
return &ret->sock;
}
ret->oobinline = false;
uxsel_tell(ret);
add234(sktree, ret);
return &ret->sock;
}
static int try_connect(NetSocket *sock)
{
int s;
union sockaddr_union u;
const union sockaddr_union *sa;
int err = 0;
short localport;
int salen, family;
/*
* Remove the socket from the tree before we overwrite its
* internal socket id, because that forms part of the tree's
* sorting criterion. We'll add it back before exiting this
* function, whether we changed anything or not.
*/
del234(sktree, sock);
if (sock->s >= 0)
close(sock->s);
{
SockAddr thisaddr = sk_extractaddr_tmp(
sock->addr, &sock->step);
plug_log(sock->plug, 0, &thisaddr, sock->port, NULL, 0);
}
/*
* Open socket.
*/
family = SOCKADDR_FAMILY(sock->addr, sock->step);
assert(family != AF_UNSPEC);
s = socket(family, SOCK_STREAM, 0);
sock->s = s;
if (s < 0) {
err = errno;
goto ret;
}
cloexec(s);
if (sock->oobinline) {
int b = 1;
if (setsockopt(s, SOL_SOCKET, SO_OOBINLINE,
(void *) &b, sizeof(b)) < 0) {
err = errno;
close(s);
goto ret;
}
}
if (sock->nodelay) {
int b = 1;
if (setsockopt(s, IPPROTO_TCP, TCP_NODELAY,
(void *) &b, sizeof(b)) < 0) {
err = errno;
close(s);
goto ret;
}
}
if (sock->keepalive) {
int b = 1;
if (setsockopt(s, SOL_SOCKET, SO_KEEPALIVE,
(void *) &b, sizeof(b)) < 0) {
err = errno;
close(s);
goto ret;
}
}
/*
* Bind to local address.
*/
if (sock->privport)
localport = 1023; /* count from 1023 downwards */
else
localport = 0; /* just use port 0 (ie kernel picks) */
/* BSD IP stacks need sockaddr_in zeroed before filling in */
memset(&u,'\0',sizeof(u));
/* We don't try to bind to a local address for UNIX domain sockets. (Why
* do we bother doing the bind when localport == 0 anyway?) */
if (family != AF_UNIX) {
/* Loop round trying to bind */
while (1) {
int retcode;
#ifndef NO_IPV6
if (family == AF_INET6) {
/* XXX use getaddrinfo to get a local address? */
u.sin6.sin6_family = AF_INET6;
u.sin6.sin6_addr = in6addr_any;
u.sin6.sin6_port = htons(localport);
retcode = bind(s, &u.sa, sizeof(u.sin6));
} else
#endif
{
assert(family == AF_INET);
u.sin.sin_family = AF_INET;
u.sin.sin_addr.s_addr = htonl(INADDR_ANY);
u.sin.sin_port = htons(localport);
retcode = bind(s, &u.sa, sizeof(u.sin));
}
if (retcode >= 0) {
err = 0;
break; /* done */
} else {
err = errno;
if (err != EADDRINUSE) /* failed, for a bad reason */
break;
}
if (localport == 0)
break; /* we're only looping once */
localport--;
if (localport == 0)
break; /* we might have got to the end */
}
if (err)
goto ret;
}
/*
* Connect to remote address.
*/
switch(family) {
#ifndef NO_IPV6
case AF_INET:
/* XXX would be better to have got getaddrinfo() to fill in the port. */
((struct sockaddr_in *)sock->step.ai->ai_addr)->sin_port =
htons(sock->port);
sa = (const union sockaddr_union *)sock->step.ai->ai_addr;
salen = sock->step.ai->ai_addrlen;
break;
case AF_INET6:
((struct sockaddr_in *)sock->step.ai->ai_addr)->sin_port =
htons(sock->port);
sa = (const union sockaddr_union *)sock->step.ai->ai_addr;
salen = sock->step.ai->ai_addrlen;
break;
#else
case AF_INET:
u.sin.sin_family = AF_INET;
u.sin.sin_addr.s_addr = htonl(sock->addr->addresses[sock->step.curraddr]);
u.sin.sin_port = htons((short) sock->port);
sa = &u;
salen = sizeof u.sin;
break;
#endif
case AF_UNIX:
assert(sock->port == 0); /* to catch confused people */
assert(strlen(sock->addr->hostname) < sizeof u.su.sun_path);
u.su.sun_family = AF_UNIX;
strcpy(u.su.sun_path, sock->addr->hostname);
sa = &u;
salen = sizeof u.su;
break;
default:
unreachable("unknown address family");
exit(1); /* XXX: GCC doesn't understand assert() on some systems. */
}
nonblock(s);
if ((connect(s, &(sa->sa), salen)) < 0) {
if ( errno != EINPROGRESS ) {
err = errno;
goto ret;
}
} else {
/*
* If we _don't_ get EWOULDBLOCK, the connect has completed
* and we should set the socket as connected and writable.
*/
sock->connected = true;
sock->writable = true;
}
uxsel_tell(sock);
ret:
/*
* No matter what happened, put the socket back in the tree.
*/
add234(sktree, sock);
if (err) {
SockAddr thisaddr = sk_extractaddr_tmp(
sock->addr, &sock->step);
plug_log(sock->plug, 1, &thisaddr, sock->port, strerror(err), err);
}
return err;
}
Socket *sk_new(SockAddr *addr, int port, bool privport, bool oobinline,
bool nodelay, bool keepalive, Plug *plug)
{
NetSocket *ret;
int err;
/*
* Create NetSocket structure.
*/
ret = snew(NetSocket);
ret->sock.vt = &NetSocket_sockvt;
ret->error = NULL;
ret->plug = plug;
bufchain_init(&ret->output_data);
ret->connected = false; /* to start with */
ret->writable = false; /* to start with */
ret->sending_oob = 0;
ret->frozen = false;
ret->localhost_only = false; /* unused, but best init anyway */
ret->pending_error = 0;
ret->parent = ret->child = NULL;
ret->oobpending = false;
ret->outgoingeof = EOF_NO;
ret->incomingeof = false;
ret->listener = false;
ret->addr = addr;
START_STEP(ret->addr, ret->step);
ret->s = -1;
ret->oobinline = oobinline;
ret->nodelay = nodelay;
ret->keepalive = keepalive;
ret->privport = privport;
ret->port = port;
do {
err = try_connect(ret);
} while (err && sk_nextaddr(ret->addr, &ret->step));
if (err)
ret->error = strerror(err);
return &ret->sock;
}
Socket *sk_newlistener(const char *srcaddr, int port, Plug *plug,
bool local_host_only, int orig_address_family)
{
int s;
#ifndef NO_IPV6
struct addrinfo hints, *ai = NULL;
char portstr[6];
#endif
union sockaddr_union u;
union sockaddr_union *addr;
int addrlen;
NetSocket *ret;
int retcode;
int address_family;
int on = 1;
/*
* Create NetSocket structure.
*/
ret = snew(NetSocket);
ret->sock.vt = &NetSocket_sockvt;
ret->error = NULL;
ret->plug = plug;
bufchain_init(&ret->output_data);
ret->writable = false; /* to start with */
ret->sending_oob = 0;
ret->frozen = false;
ret->localhost_only = local_host_only;
ret->pending_error = 0;
ret->parent = ret->child = NULL;
ret->oobpending = false;
ret->outgoingeof = EOF_NO;
ret->incomingeof = false;
ret->listener = true;
ret->addr = NULL;
ret->s = -1;
/*
* Translate address_family from platform-independent constants
* into local reality.
*/
address_family = (orig_address_family == ADDRTYPE_IPV4 ? AF_INET :
#ifndef NO_IPV6
orig_address_family == ADDRTYPE_IPV6 ? AF_INET6 :
#endif
AF_UNSPEC);
#ifndef NO_IPV6
/* Let's default to IPv6.
* If the stack doesn't support IPv6, we will fall back to IPv4. */
if (address_family == AF_UNSPEC) address_family = AF_INET6;
#else
/* No other choice, default to IPv4 */
if (address_family == AF_UNSPEC) address_family = AF_INET;
#endif
/*
* Open socket.
*/
s = socket(address_family, SOCK_STREAM, 0);
#ifndef NO_IPV6
/* If the host doesn't support IPv6 try fallback to IPv4. */
if (s < 0 && address_family == AF_INET6) {
address_family = AF_INET;
s = socket(address_family, SOCK_STREAM, 0);
}
#endif
if (s < 0) {
ret->error = strerror(errno);
return &ret->sock;
}
cloexec(s);
ret->oobinline = false;
if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
(const char *)&on, sizeof(on)) < 0) {
ret->error = strerror(errno);
close(s);
return &ret->sock;
}
retcode = -1;
addr = NULL; addrlen = -1; /* placate optimiser */
if (srcaddr != NULL) {
#ifndef NO_IPV6
hints.ai_flags = AI_NUMERICHOST;
hints.ai_family = address_family;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = 0;
hints.ai_addrlen = 0;
hints.ai_addr = NULL;
hints.ai_canonname = NULL;
hints.ai_next = NULL;
assert(port >= 0 && port <= 99999);
sprintf(portstr, "%d", port);
{
char *trimmed_addr = host_strduptrim(srcaddr);
retcode = getaddrinfo(trimmed_addr, portstr, &hints, &ai);
sfree(trimmed_addr);
}
if (retcode == 0) {
addr = (union sockaddr_union *)ai->ai_addr;
addrlen = ai->ai_addrlen;
}
#else
memset(&u,'\0',sizeof u);
u.sin.sin_family = AF_INET;
u.sin.sin_port = htons(port);
u.sin.sin_addr.s_addr = inet_addr(srcaddr);
if (u.sin.sin_addr.s_addr != (in_addr_t)(-1)) {
/* Override localhost_only with specified listen addr. */
ret->localhost_only = ipv4_is_loopback(u.sin.sin_addr);
}
addr = &u;
addrlen = sizeof(u.sin);
retcode = 0;
#endif
}
if (retcode != 0) {
memset(&u,'\0',sizeof u);
#ifndef NO_IPV6
if (address_family == AF_INET6) {
u.sin6.sin6_family = AF_INET6;
u.sin6.sin6_port = htons(port);
if (local_host_only)
u.sin6.sin6_addr = in6addr_loopback;
else
u.sin6.sin6_addr = in6addr_any;
addr = &u;
addrlen = sizeof(u.sin6);
} else
#endif
{
u.sin.sin_family = AF_INET;
u.sin.sin_port = htons(port);
if (local_host_only)
u.sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
else
u.sin.sin_addr.s_addr = htonl(INADDR_ANY);
addr = &u;
addrlen = sizeof(u.sin);
}
}
retcode = bind(s, &addr->sa, addrlen);
#ifndef NO_IPV6
if (ai)
freeaddrinfo(ai);
#endif
if (retcode < 0) {
close(s);
ret->error = strerror(errno);
return &ret->sock;
}
if (listen(s, SOMAXCONN) < 0) {
close(s);
ret->error = strerror(errno);
return &ret->sock;
}
#ifndef NO_IPV6
/*
* If we were given ADDRTYPE_UNSPEC, we must also create an
* IPv4 listening socket and link it to this one.
*/
if (address_family == AF_INET6 && orig_address_family == ADDRTYPE_UNSPEC) {
NetSocket *other;
other = container_of(
sk_newlistener(srcaddr, port, plug,
local_host_only, ADDRTYPE_IPV4),
NetSocket, sock);
if (other) {
if (!other->error) {
other->parent = ret;
ret->child = other;
} else {
/* If we couldn't create a listening socket on IPv4 as well
* as IPv6, we must return an error overall. */
close(s);
sfree(ret);
return &other->sock;
}
}
}
#endif
ret->s = s;
uxsel_tell(ret);
add234(sktree, ret);
return &ret->sock;
}
static void sk_net_close(Socket *sock)
{
NetSocket *s = container_of(sock, NetSocket, sock);
if (s->child)
sk_net_close(&s->child->sock);
bufchain_clear(&s->output_data);
del234(sktree, s);
if (s->s >= 0) {
uxsel_del(s->s);
close(s->s);
}
if (s->addr)
sk_addr_free(s->addr);
delete_callbacks_for_context(s);
sfree(s);
}
void *sk_getxdmdata(Socket *sock, int *lenp)
{
NetSocket *s;
union sockaddr_union u;
socklen_t addrlen;
char *buf;
static unsigned int unix_addr = 0xFFFFFFFF;
/*
* We must check that this socket really _is_ a NetSocket before
* downcasting it.
*/
if (sock->vt != &NetSocket_sockvt)
return NULL; /* failure */
s = container_of(sock, NetSocket, sock);
addrlen = sizeof(u);
if (getsockname(s->s, &u.sa, &addrlen) < 0)
return NULL;
switch(u.sa.sa_family) {
case AF_INET:
*lenp = 6;
buf = snewn(*lenp, char);
PUT_32BIT_MSB_FIRST(buf, ntohl(u.sin.sin_addr.s_addr));
PUT_16BIT_MSB_FIRST(buf+4, ntohs(u.sin.sin_port));
break;
#ifndef NO_IPV6
case AF_INET6:
*lenp = 6;
buf = snewn(*lenp, char);
if (IN6_IS_ADDR_V4MAPPED(&u.sin6.sin6_addr)) {
memcpy(buf, u.sin6.sin6_addr.s6_addr + 12, 4);
PUT_16BIT_MSB_FIRST(buf+4, ntohs(u.sin6.sin6_port));
} else
/* This is stupid, but it's what XLib does. */
memset(buf, 0, 6);
break;
#endif
case AF_UNIX:
*lenp = 6;
buf = snewn(*lenp, char);
PUT_32BIT_MSB_FIRST(buf, unix_addr--);
PUT_16BIT_MSB_FIRST(buf+4, getpid());
break;
/* XXX IPV6 */
default:
return NULL;
}
return buf;
}
/*
* Deal with socket errors detected in try_send().
*/
static void socket_error_callback(void *vs)
{
NetSocket *s = (NetSocket *)vs;
/*
* Just in case other socket work has caused this socket to vanish
* or become somehow non-erroneous before this callback arrived...
*/
if (!find234(sktree, s, NULL) || !s->pending_error)
return;
/*
* An error has occurred on this socket. Pass it to the plug.
*/
plug_closing(s->plug, strerror(s->pending_error), s->pending_error, 0);
}
/*
* The function which tries to send on a socket once it's deemed
* writable.
*/
void try_send(NetSocket *s)
{
while (s->sending_oob || bufchain_size(&s->output_data) > 0) {
int nsent;
int err;
const void *data;
size_t len;
int urgentflag;
if (s->sending_oob) {
urgentflag = MSG_OOB;
len = s->sending_oob;
data = &s->oobdata;
} else {
urgentflag = 0;
ptrlen bufdata = bufchain_prefix(&s->output_data);
data = bufdata.ptr;
len = bufdata.len;
}
nsent = send(s->s, data, len, urgentflag);
noise_ultralight(NOISE_SOURCE_IOLEN, nsent);
if (nsent <= 0) {
err = (nsent < 0 ? errno : 0);
if (err == EWOULDBLOCK) {
/*
* Perfectly normal: we've sent all we can for the moment.
*/
s->writable = false;
return;
} else {
/*
* We unfortunately can't just call plug_closing(),
* because it's quite likely that we're currently
* _in_ a call from the code we'd be calling back
* to, so we'd have to make half the SSH code
* reentrant. Instead we flag a pending error on
* the socket, to be dealt with (by calling
* plug_closing()) at some suitable future moment.
*/
s->pending_error = err;
/*
* Immediately cease selecting on this socket, so that
* we don't tight-loop repeatedly trying to do
* whatever it was that went wrong.
*/
uxsel_tell(s);
/*
* Arrange to be called back from the top level to
* deal with the error condition on this socket.
*/
queue_toplevel_callback(socket_error_callback, s);
return;
}
} else {
if (s->sending_oob) {
if (nsent < len) {
memmove(s->oobdata, s->oobdata+nsent, len-nsent);
s->sending_oob = len - nsent;
} else {
s->sending_oob = 0;
}
} else {
bufchain_consume(&s->output_data, nsent);
}
}
}
/*
* If we reach here, we've finished sending everything we might
* have needed to send. Send EOF, if we need to.
*/
if (s->outgoingeof == EOF_PENDING) {
shutdown(s->s, SHUT_WR);
s->outgoingeof = EOF_SENT;
}
/*
* Also update the select status, because we don't need to select
* for writing any more.
*/
uxsel_tell(s);
}
static size_t sk_net_write(Socket *sock, const void *buf, size_t len)
{
NetSocket *s = container_of(sock, NetSocket, sock);
assert(s->outgoingeof == EOF_NO);
/*
* Add the data to the buffer list on the socket.
*/
bufchain_add(&s->output_data, buf, len);
/*
* Now try sending from the start of the buffer list.
*/
if (s->writable)
try_send(s);
/*
* Update the select() status to correctly reflect whether or
* not we should be selecting for write.
*/
uxsel_tell(s);
return bufchain_size(&s->output_data);
}
static size_t sk_net_write_oob(Socket *sock, const void *buf, size_t len)
{
NetSocket *s = container_of(sock, NetSocket, sock);
assert(s->outgoingeof == EOF_NO);
/*
* Replace the buffer list on the socket with the data.
*/
bufchain_clear(&s->output_data);
assert(len <= sizeof(s->oobdata));
memcpy(s->oobdata, buf, len);
s->sending_oob = len;
/*
* Now try sending from the start of the buffer list.
*/
if (s->writable)
try_send(s);
/*
* Update the select() status to correctly reflect whether or
* not we should be selecting for write.
*/
uxsel_tell(s);
return s->sending_oob;
}
static void sk_net_write_eof(Socket *sock)
{
NetSocket *s = container_of(sock, NetSocket, sock);
assert(s->outgoingeof == EOF_NO);
/*
* Mark the socket as pending outgoing EOF.
*/
s->outgoingeof = EOF_PENDING;
/*
* Now try sending from the start of the buffer list.
*/
if (s->writable)
try_send(s);
/*
* Update the select() status to correctly reflect whether or
* not we should be selecting for write.
*/
uxsel_tell(s);
}
static void net_select_result(int fd, int event)
{
int ret;
char buf[20480]; /* nice big buffer for plenty of speed */
NetSocket *s;
bool atmark = true;
/* Find the Socket structure */
s = find234(sktree, &fd, cmpforsearch);
if (!s)
return; /* boggle */
noise_ultralight(NOISE_SOURCE_IOID, fd);
switch (event) {
case 4: /* exceptional */
if (!s->oobinline) {
/*
* On a non-oobinline socket, this indicates that we
* can immediately perform an OOB read and get back OOB
* data, which we will send to the back end with
* type==2 (urgent data).
*/
ret = recv(s->s, buf, sizeof(buf), MSG_OOB);
noise_ultralight(NOISE_SOURCE_IOLEN, ret);
if (ret <= 0) {
plug_closing(s->plug,
ret == 0 ? "Internal networking trouble" :
strerror(errno), errno, 0);
} else {
/*
* Receiving actual data on a socket means we can
* stop falling back through the candidate
* addresses to connect to.
*/
if (s->addr) {
sk_addr_free(s->addr);
s->addr = NULL;
}
plug_receive(s->plug, 2, buf, ret);
}
break;
}
/*
* If we reach here, this is an oobinline socket, which
* means we should set s->oobpending and then deal with it
* when we get called for the readability event (which
* should also occur).
*/
s->oobpending = true;
break;
case 1: /* readable; also acceptance */
if (s->listener) {
/*
* On a listening socket, the readability event means a
* connection is ready to be accepted.
*/
union sockaddr_union su;
socklen_t addrlen = sizeof(su);
accept_ctx_t actx;
int t; /* socket of connection */
memset(&su, 0, addrlen);
t = accept(s->s, &su.sa, &addrlen);
if (t < 0) {
break;
}
nonblock(t);
actx.i = t;
if ((!s->addr || s->addr->superfamily != UNIX) &&
s->localhost_only && !sockaddr_is_loopback(&su.sa)) {
close(t); /* someone let nonlocal through?! */
} else if (plug_accepting(s->plug, sk_net_accept, actx)) {
close(t); /* denied or error */
}
break;
}
/*
* If we reach here, this is not a listening socket, so
* readability really means readability.
*/
/* In the case the socket is still frozen, we don't even bother */
if (s->frozen)
break;
/*
* We have received data on the socket. For an oobinline
* socket, this might be data _before_ an urgent pointer,
* in which case we send it to the back end with type==1
* (data prior to urgent).
*/
if (s->oobinline && s->oobpending) {
int atmark_from_ioctl;
if (ioctl(s->s, SIOCATMARK, &atmark_from_ioctl) == 0) {
atmark = atmark_from_ioctl;
if (atmark)
s->oobpending = false; /* clear this indicator */
}
} else
atmark = true;
ret = recv(s->s, buf, s->oobpending ? 1 : sizeof(buf), 0);
noise_ultralight(NOISE_SOURCE_IOLEN, ret);
if (ret < 0) {
if (errno == EWOULDBLOCK) {
break;
}
}
if (ret < 0) {
plug_closing(s->plug, strerror(errno), errno, 0);
} else if (0 == ret) {
s->incomingeof = true; /* stop trying to read now */
uxsel_tell(s);
plug_closing(s->plug, NULL, 0, 0);
} else {
/*
* Receiving actual data on a socket means we can
* stop falling back through the candidate
* addresses to connect to.
*/
if (s->addr) {
sk_addr_free(s->addr);
s->addr = NULL;
}
plug_receive(s->plug, atmark ? 0 : 1, buf, ret);
}
break;
case 2: /* writable */
if (!s->connected) {
/*
* select() reports a socket as _writable_ when an
* asynchronous connect() attempt either completes or
* fails. So first we must find out which.
*/
{
int err;
socklen_t errlen = sizeof(err);
char *errmsg = NULL;
if (getsockopt(s->s, SOL_SOCKET, SO_ERROR, &err, &errlen)<0) {
errmsg = dupprintf("getsockopt(SO_ERROR): %s",
strerror(errno));
err = errno; /* got to put something in here */
} else if (err != 0) {
errmsg = dupstr(strerror(err));
}
if (errmsg) {
/*
* The asynchronous connection attempt failed.
* Report the problem via plug_log, and try again
* with the next candidate address, if we have
* more than one.
*/
SockAddr thisaddr;
assert(s->addr);
thisaddr = sk_extractaddr_tmp(s->addr, &s->step);
plug_log(s->plug, 1, &thisaddr, s->port, errmsg, err);
while (err && s->addr && sk_nextaddr(s->addr, &s->step)) {
err = try_connect(s);
}
if (err) {
plug_closing(s->plug, strerror(err), err, 0);
return; /* socket is now presumably defunct */
}
if (!s->connected)
return; /* another async attempt in progress */
}
}
/*
* If we get here, we've managed to make a connection.
*/
if (s->addr) {
sk_addr_free(s->addr);
s->addr = NULL;
}
s->connected = true;
s->writable = true;
uxsel_tell(s);
} else {
size_t bufsize_before, bufsize_after;
s->writable = true;
bufsize_before = s->sending_oob + bufchain_size(&s->output_data);
try_send(s);
bufsize_after = s->sending_oob + bufchain_size(&s->output_data);
if (bufsize_after < bufsize_before)
plug_sent(s->plug, bufsize_after);
}
break;
}
}
/*
* Special error values are returned from sk_namelookup and sk_new
* if there's a problem. These functions extract an error message,
* or return NULL if there's no problem.
*/
const char *sk_addr_error(SockAddr *addr)
{
return addr->error;
}
static const char *sk_net_socket_error(Socket *sock)
{
NetSocket *s = container_of(sock, NetSocket, sock);
return s->error;
}
static void sk_net_set_frozen(Socket *sock, bool is_frozen)
{
NetSocket *s = container_of(sock, NetSocket, sock);
if (s->frozen == is_frozen)
return;
s->frozen = is_frozen;
uxsel_tell(s);
}
static SocketPeerInfo *sk_net_peer_info(Socket *sock)
{
NetSocket *s = container_of(sock, NetSocket, sock);
union sockaddr_union addr;
socklen_t addrlen = sizeof(addr);
#ifndef NO_IPV6
char buf[INET6_ADDRSTRLEN];
#endif
SocketPeerInfo *pi;
if (getpeername(s->s, &addr.sa, &addrlen) < 0)
return NULL;
pi = snew(SocketPeerInfo);
pi->addressfamily = ADDRTYPE_UNSPEC;
pi->addr_text = NULL;
pi->port = -1;
pi->log_text = NULL;
if (addr.storage.ss_family == AF_INET) {
pi->addressfamily = ADDRTYPE_IPV4;
memcpy(pi->addr_bin.ipv4, &addr.sin.sin_addr, 4);
pi->port = ntohs(addr.sin.sin_port);
pi->addr_text = dupstr(inet_ntoa(addr.sin.sin_addr));
pi->log_text = dupprintf("%s:%d", pi->addr_text, pi->port);
#ifndef NO_IPV6
} else if (addr.storage.ss_family == AF_INET6) {
pi->addressfamily = ADDRTYPE_IPV6;
memcpy(pi->addr_bin.ipv6, &addr.sin6.sin6_addr, 16);
pi->port = ntohs(addr.sin6.sin6_port);
pi->addr_text = dupstr(
inet_ntop(AF_INET6, &addr.sin6.sin6_addr, buf, sizeof(buf)));
pi->log_text = dupprintf("[%s]:%d", pi->addr_text, pi->port);
#endif
} else if (addr.storage.ss_family == AF_UNIX) {
pi->addressfamily = ADDRTYPE_LOCAL;
/*
* For Unix sockets, the source address is unlikely to be
* helpful, so we leave addr_txt NULL (and we certainly can't
* fill in port, obviously). Instead, we try SO_PEERCRED and
* try to get the source pid, and put that in the log text.
*/
int pid, uid, gid;
if (so_peercred(s->s, &pid, &uid, &gid)) {
char uidbuf[64], gidbuf[64];
sprintf(uidbuf, "%d", uid);
sprintf(gidbuf, "%d", gid);
struct passwd *pw = getpwuid(uid);
struct group *gr = getgrgid(gid);
pi->log_text = dupprintf("pid %d (%s:%s)", pid,
pw ? pw->pw_name : uidbuf,
gr ? gr->gr_name : gidbuf);
}
} else {
sfree(pi);
return NULL;
}
return pi;
}
static void uxsel_tell(NetSocket *s)
{
int rwx = 0;
if (!s->pending_error) {
if (s->listener) {
rwx |= 1; /* read == accept */
} else {
if (!s->connected)
rwx |= 2; /* write == connect */
if (s->connected && !s->frozen && !s->incomingeof)
rwx |= 1 | 4; /* read, except */
if (bufchain_size(&s->output_data))
rwx |= 2; /* write */
}
}
uxsel_set(s->s, rwx, net_select_result);
}
int net_service_lookup(char *service)
{
struct servent *se;
se = getservbyname(service, NULL);
if (se != NULL)
return ntohs(se->s_port);
else
return 0;
}
char *get_hostname(void)
{
size_t size = 0;
char *hostname = NULL;
do {
sgrowarray(hostname, size, size);
if ((gethostname(hostname, size) < 0) && (errno != ENAMETOOLONG)) {
sfree(hostname);
hostname = NULL;
break;
}
} while (strlen(hostname) >= size-1);
return hostname;
}
SockAddr *platform_get_x11_unix_address(const char *sockpath, int displaynum)
{
SockAddr *ret = snew(SockAddr);
int n;
memset(ret, 0, sizeof *ret);
ret->superfamily = UNIX;
/*
* In special circumstances (notably Mac OS X Leopard), we'll
* have been passed an explicit Unix socket path.
*/
if (sockpath) {
n = snprintf(ret->hostname, sizeof ret->hostname,
"%s", sockpath);
} else {
n = snprintf(ret->hostname, sizeof ret->hostname,
"%s%d", X11_UNIX_PATH, displaynum);
}
if (n < 0)
ret->error = "snprintf failed";
else if (n >= sizeof ret->hostname)
ret->error = "X11 UNIX name too long";
#ifndef NO_IPV6
ret->ais = NULL;
#else
ret->addresses = NULL;
ret->naddresses = 0;
#endif
ret->refcount = 1;
return ret;
}
SockAddr *unix_sock_addr(const char *path)
{
SockAddr *ret = snew(SockAddr);
int n;
memset(ret, 0, sizeof *ret);
ret->superfamily = UNIX;
n = snprintf(ret->hostname, sizeof ret->hostname, "%s", path);
if (n < 0)
ret->error = "snprintf failed";
else if (n >= sizeof ret->hostname ||
n >= sizeof(((struct sockaddr_un *)0)->sun_path))
ret->error = "socket pathname too long";
#ifndef NO_IPV6
ret->ais = NULL;
#else
ret->addresses = NULL;
ret->naddresses = 0;
#endif
ret->refcount = 1;
return ret;
}
Socket *new_unix_listener(SockAddr *listenaddr, Plug *plug)
{
int s;
union sockaddr_union u;
union sockaddr_union *addr;
int addrlen;
NetSocket *ret;
int retcode;
/*
* Create NetSocket structure.
*/
ret = snew(NetSocket);
ret->sock.vt = &NetSocket_sockvt;
ret->error = NULL;
ret->plug = plug;
bufchain_init(&ret->output_data);
ret->writable = false; /* to start with */
ret->sending_oob = 0;
ret->frozen = false;
ret->localhost_only = true;
ret->pending_error = 0;
ret->parent = ret->child = NULL;
ret->oobpending = false;
ret->outgoingeof = EOF_NO;
ret->incomingeof = false;
ret->listener = true;
ret->addr = listenaddr;
ret->s = -1;
assert(listenaddr->superfamily == UNIX);
/*
* Open socket.
*/
s = socket(AF_UNIX, SOCK_STREAM, 0);
if (s < 0) {
ret->error = strerror(errno);
return &ret->sock;
}
cloexec(s);
ret->oobinline = false;
memset(&u, '\0', sizeof(u));
u.su.sun_family = AF_UNIX;
#if __GNUC__ >= 8
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wstringop-truncation"
#endif // __GNUC__ >= 8
strncpy(u.su.sun_path, listenaddr->hostname, sizeof(u.su.sun_path)-1);
#if __GNUC__ >= 8
# pragma GCC diagnostic pop
#endif // __GNUC__ >= 8
addr = &u;
addrlen = sizeof(u.su);
if (unlink(u.su.sun_path) < 0 && errno != ENOENT) {
close(s);
ret->error = strerror(errno);
return &ret->sock;
}
retcode = bind(s, &addr->sa, addrlen);
if (retcode < 0) {
close(s);
ret->error = strerror(errno);
return &ret->sock;
}
if (listen(s, SOMAXCONN) < 0) {
close(s);
ret->error = strerror(errno);
return &ret->sock;
}
ret->s = s;
uxsel_tell(ret);
add234(sktree, ret);
return &ret->sock;
}
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