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mirror of https://git.tartarus.org/simon/putty.git synced 2025-01-10 01:48:00 +00:00
putty-source/unix/uxnet.c
Simon Tatham 5129c40bea Modernise the Socket/Plug vtable system.
Now I've got FROMFIELD, I can rework it so that structures providing
an implementation of the Socket or Plug trait no longer have to have
the vtable pointer as the very first thing in the structure. In
particular, this means that the ProxySocket structure can now directly
implement _both_ the Socket and Plug traits, which is always
_logically_ how it's worked, but previously it had to be implemented
via two separate structs linked to each other.
2018-05-27 15:28:54 +01:00

1711 lines
42 KiB
C

/*
* 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>
#define DEFINE_PLUG_METHOD_MACROS
#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;
int connected; /* irrelevant for listening sockets */
int writable;
int frozen; /* this causes readability notifications to be ignored */
int localhost_only; /* for listening sockets */
char oobdata[1];
int sending_oob;
int oobpending; /* is there OOB data available to read? */
int oobinline;
enum { EOF_NO, EOF_PENDING, EOF_SENT } outgoingeof;
int incomingeof;
int pending_error; /* in case send() returns error */
int listener;
int nodelay, keepalive; /* for connect()-type sockets */
int privport, 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;
const Socket_vtable *sockvt;
};
struct SockAddr_tag {
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(struct SockAddr_tag);
#ifndef NO_IPV6
struct addrinfo hints;
int err;
#else
unsigned long a;
struct hostent *h = NULL;
int n;
#endif
char realhost[8192];
/* Clear the structure and default to IPv4. */
memset(ret, 0, sizeof(struct SockAddr_tag));
ret->superfamily = UNRESOLVED;
*realhost = '\0';
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;
*realhost = '\0';
if (ret->ais->ai_canonname != NULL)
strncat(realhost, ret->ais->ai_canonname, sizeof(realhost) - 1);
else
strncat(realhost, host, sizeof(realhost) - 1);
#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");
return ret;
}
/* This way we are always sure the h->h_name is valid :) */
strncpy(realhost, h->h_name, sizeof(realhost));
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;
strncpy(realhost, host, sizeof(realhost));
ret->addresses = snew(unsigned long);
ret->naddresses = 1;
ret->addresses[0] = ntohl(a);
}
#endif
realhost[lenof(realhost)-1] = '\0';
*canonicalname = snewn(1+strlen(realhost), char);
strcpy(*canonicalname, realhost);
return ret;
}
SockAddr sk_nonamelookup(const char *host)
{
SockAddr ret = snew(struct SockAddr_tag);
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 int 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 struct SockAddr_tag sk_extractaddr_tmp(
SockAddr addr, const SockAddrStep *step)
{
struct SockAddr_tag 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;
}
int sk_addr_needs_port(SockAddr addr)
{
if (addr->superfamily == UNRESOLVED || addr->superfamily == UNIX) {
return FALSE;
} else {
return TRUE;
}
}
int 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 int 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;
}
}
int sk_address_is_local(SockAddr addr)
{
if (addr->superfamily == UNRESOLVED)
return 0; /* we don't know; assume not */
else if (addr->superfamily == UNIX)
return 1;
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
}
}
int 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
assert(FALSE);
#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 = FROMFIELD(sock, NetSocket, sockvt);
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 int sk_net_write(Socket s, const void *data, int len);
static int sk_net_write_oob(Socket s, const void *data, int len);
static void sk_net_write_eof(Socket s);
static void sk_net_set_frozen(Socket s, int is_frozen);
static char *sk_net_peer_info(Socket s);
static const char *sk_net_socket_error(Socket s);
static struct Socket_vtable 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->sockvt = &NetSocket_sockvt;
ret->error = NULL;
ret->plug = plug;
bufchain_init(&ret->output_data);
ret->writable = 1; /* to start with */
ret->sending_oob = 0;
ret->frozen = 1;
ret->localhost_only = 0; /* unused, but best init anyway */
ret->pending_error = 0;
ret->oobpending = FALSE;
ret->outgoingeof = EOF_NO;
ret->incomingeof = FALSE;
ret->listener = 0;
ret->parent = ret->child = NULL;
ret->addr = NULL;
ret->connected = 1;
ret->s = sockfd;
if (ret->s < 0) {
ret->error = strerror(errno);
return &ret->sockvt;
}
ret->oobinline = 0;
uxsel_tell(ret);
add234(sktree, ret);
return &ret->sockvt;
}
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);
{
struct SockAddr_tag 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 = TRUE;
if (setsockopt(s, SOL_SOCKET, SO_OOBINLINE,
(void *) &b, sizeof(b)) < 0) {
err = errno;
close(s);
goto ret;
}
}
if (sock->nodelay) {
int b = TRUE;
if (setsockopt(s, IPPROTO_TCP, TCP_NODELAY,
(void *) &b, sizeof(b)) < 0) {
err = errno;
close(s);
goto ret;
}
}
if (sock->keepalive) {
int b = TRUE;
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:
assert(0 && "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 = 1;
sock->writable = 1;
}
uxsel_tell(sock);
ret:
/*
* No matter what happened, put the socket back in the tree.
*/
add234(sktree, sock);
if (err) {
struct SockAddr_tag 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, int privport, int oobinline,
int nodelay, int keepalive, Plug plug)
{
NetSocket *ret;
int err;
/*
* Create NetSocket structure.
*/
ret = snew(NetSocket);
ret->sockvt = &NetSocket_sockvt;
ret->error = NULL;
ret->plug = plug;
bufchain_init(&ret->output_data);
ret->connected = 0; /* to start with */
ret->writable = 0; /* to start with */
ret->sending_oob = 0;
ret->frozen = 0;
ret->localhost_only = 0; /* 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 = 0;
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;
err = 0;
do {
err = try_connect(ret);
} while (err && sk_nextaddr(ret->addr, &ret->step));
if (err)
ret->error = strerror(err);
return &ret->sockvt;
}
Socket sk_newlistener(const char *srcaddr, int port, Plug plug,
int 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->sockvt = &NetSocket_sockvt;
ret->error = NULL;
ret->plug = plug;
bufchain_init(&ret->output_data);
ret->writable = 0; /* to start with */
ret->sending_oob = 0;
ret->frozen = 0;
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 = 1;
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->sockvt;
}
cloexec(s);
ret->oobinline = 0;
if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
(const char *)&on, sizeof(on)) < 0) {
ret->error = strerror(errno);
close(s);
return &ret->sockvt;
}
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->sockvt;
}
if (listen(s, SOMAXCONN) < 0) {
close(s);
ret->error = strerror(errno);
return &ret->sockvt;
}
#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 = FROMFIELD(
sk_newlistener(srcaddr, port, plug,
local_host_only, ADDRTYPE_IPV4),
NetSocket, sockvt);
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->sockvt;
}
}
}
#endif
ret->s = s;
uxsel_tell(ret);
add234(sktree, ret);
return &ret->sockvt;
}
static void sk_net_close(Socket sock)
{
NetSocket *s = FROMFIELD(sock, NetSocket, sockvt);
if (s->child)
sk_net_close(&s->child->sockvt);
del234(sktree, s);
if (s->s >= 0) {
uxsel_del(s->s);
close(s->s);
}
if (s->addr)
sk_addr_free(s->addr);
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 != &NetSocket_sockvt)
return NULL; /* failure */
s = FROMFIELD(sock, NetSocket, sockvt);
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;
void *data;
int len, urgentflag;
if (s->sending_oob) {
urgentflag = MSG_OOB;
len = s->sending_oob;
data = &s->oobdata;
} else {
urgentflag = 0;
bufchain_prefix(&s->output_data, &data, &len);
}
nsent = send(s->s, data, len, urgentflag);
noise_ultralight(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 int sk_net_write(Socket sock, const void *buf, int len)
{
NetSocket *s = FROMFIELD(sock, NetSocket, sockvt);
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 int sk_net_write_oob(Socket sock, const void *buf, int len)
{
NetSocket *s = FROMFIELD(sock, NetSocket, sockvt);
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 = FROMFIELD(sock, NetSocket, sockvt);
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;
u_long atmark;
/* Find the Socket structure */
s = find234(sktree, &fd, cmpforsearch);
if (!s)
return; /* boggle */
noise_ultralight(event);
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(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) {
atmark = 1;
if (ioctl(s->s, SIOCATMARK, &atmark) == 0 && atmark)
s->oobpending = FALSE; /* clear this indicator */
} else
atmark = 1;
ret = recv(s->s, buf, s->oobpending ? 1 : sizeof(buf), 0);
noise_ultralight(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.
*/
struct SockAddr_tag 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 = s->writable = 1;
uxsel_tell(s);
} else {
int bufsize_before, bufsize_after;
s->writable = 1;
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 = FROMFIELD(sock, NetSocket, sockvt);
return s->error;
}
static void sk_net_set_frozen(Socket sock, int is_frozen)
{
NetSocket *s = FROMFIELD(sock, NetSocket, sockvt);
if (s->frozen == is_frozen)
return;
s->frozen = is_frozen;
uxsel_tell(s);
}
static char *sk_net_peer_info(Socket sock)
{
NetSocket *s = FROMFIELD(sock, NetSocket, sockvt);
union sockaddr_union addr;
socklen_t addrlen = sizeof(addr);
#ifndef NO_IPV6
char buf[INET6_ADDRSTRLEN];
#endif
if (getpeername(s->s, &addr.sa, &addrlen) < 0)
return NULL;
if (addr.storage.ss_family == AF_INET) {
return dupprintf
("%s:%d",
inet_ntoa(addr.sin.sin_addr),
(int)ntohs(addr.sin.sin_port));
#ifndef NO_IPV6
} else if (addr.storage.ss_family == AF_INET6) {
return dupprintf
("[%s]:%d",
inet_ntop(AF_INET6, &addr.sin6.sin6_addr, buf, sizeof(buf)),
(int)ntohs(addr.sin6.sin6_port));
#endif
} else if (addr.storage.ss_family == AF_UNIX) {
/*
* For Unix sockets, the source address is unlikely to be
* helpful. Instead, we try SO_PEERCRED and try to get the
* source pid.
*/
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);
return dupprintf("pid %d (%s:%s)", pid,
pw ? pw->pw_name : uidbuf,
gr ? gr->gr_name : gidbuf);
}
return NULL;
} else {
return NULL;
}
}
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)
{
int len = 128;
char *hostname = NULL;
do {
len *= 2;
hostname = sresize(hostname, len, char);
if ((gethostname(hostname, len) < 0) &&
(errno != ENAMETOOLONG)) {
sfree(hostname);
hostname = NULL;
break;
}
} while (strlen(hostname) >= len-1);
return hostname;
}
SockAddr platform_get_x11_unix_address(const char *sockpath, int displaynum)
{
SockAddr ret = snew(struct SockAddr_tag);
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(struct SockAddr_tag);
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->sockvt = &NetSocket_sockvt;
ret->error = NULL;
ret->plug = plug;
bufchain_init(&ret->output_data);
ret->writable = 0; /* to start with */
ret->sending_oob = 0;
ret->frozen = 0;
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 = 1;
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->sockvt;
}
cloexec(s);
ret->oobinline = 0;
memset(&u, '\0', sizeof(u));
u.su.sun_family = AF_UNIX;
strncpy(u.su.sun_path, listenaddr->hostname, sizeof(u.su.sun_path)-1);
addr = &u;
addrlen = sizeof(u.su);
if (unlink(u.su.sun_path) < 0 && errno != ENOENT) {
close(s);
ret->error = strerror(errno);
return &ret->sockvt;
}
retcode = bind(s, &addr->sa, addrlen);
if (retcode < 0) {
close(s);
ret->error = strerror(errno);
return &ret->sockvt;
}
if (listen(s, SOMAXCONN) < 0) {
close(s);
ret->error = strerror(errno);
return &ret->sockvt;
}
ret->s = s;
uxsel_tell(ret);
add234(sktree, ret);
return &ret->sockvt;
}