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putty/unix/uxnet.c

1291 строка
32 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>
#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
struct Socket_tag {
struct socket_function_table *fn;
/* the above variable absolutely *must* be the first in this structure */
const char *error;
int s;
Plug plug;
void *private_ptr;
bufchain output_data;
int connected; /* irrelevant for listening sockets */
int writable;
int frozen; /* this causes readability notifications to be ignored */
int frozen_readable; /* this means we missed at least one readability
* notification while we were frozen */
int localhost_only; /* for listening sockets */
char oobdata[1];
int sending_oob;
int oobpending; /* is there OOB data available to read? */
int oobinline;
int pending_error; /* in case send() returns error */
int listener;
int nodelay, keepalive; /* for connect()-type sockets */
int privport, port; /* and again */
SockAddr addr;
};
/*
* We used to typedef struct Socket_tag *Socket.
*
* Since we have made the networking abstraction slightly more
* abstract, Socket no longer means a tcp socket (it could mean
* an ssl socket). So now we must use Actual_Socket when we know
* we are talking about a tcp socket.
*/
typedef struct Socket_tag *Actual_Socket;
struct SockAddr_tag {
const char *error;
/*
* 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.
*/
int family;
#ifndef NO_IPV6
struct addrinfo *ais; /* Addresses IPv6 style. */
struct addrinfo *ai; /* steps along the linked list */
#else
unsigned long *addresses; /* Addresses IPv4 style. */
int naddresses, curraddr;
#endif
char hostname[512]; /* Store an unresolved host name. */
};
static tree234 *sktree;
static void uxsel_tell(Actual_Socket s);
static int cmpfortree(void *av, void *bv)
{
Actual_Socket a = (Actual_Socket) av, b = (Actual_Socket) bv;
int as = a->s, bs = b->s;
if (as < bs)
return -1;
if (as > bs)
return +1;
return 0;
}
static int cmpforsearch(void *av, void *bv)
{
Actual_Socket b = (Actual_Socket) 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)
{
Actual_Socket 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->family = 0; /* We set this one when we have resolved the host. */
*realhost = '\0';
ret->error = NULL;
#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;
err = getaddrinfo(host, NULL, &hints, &ret->ais);
ret->ai = ret->ais;
if (err != 0) {
ret->error = gai_strerror(err);
return ret;
}
ret->family = ret->ai->ai_family;
*realhost = '\0';
if (ret->ai->ai_canonname != NULL)
strncat(realhost, ret->ai->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->family == 0) {
/*debug(("Resolving \"%s\" with gethostbyname() (IPv4 only)...\n", host)); */
if ( (h = gethostbyname(host)) )
ret->family = AF_INET;
}
if (ret->family == 0) {
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->family = AF_INET;
strncpy(realhost, host, sizeof(realhost));
ret->addresses = snew(unsigned long);
ret->naddresses = 1;
ret->addresses[0] = ntohl(a);
ret->curraddr = 0;
}
#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->family = AF_UNSPEC;
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
return ret;
}
static int sk_nextaddr(SockAddr addr)
{
#ifndef NO_IPV6
if (addr->ai->ai_next) {
addr->ai = addr->ai->ai_next;
addr->family = addr->ai->ai_family;
return TRUE;
} else
return FALSE;
#else
if (addr->curraddr+1 < addr->naddresses) {
addr->curraddr++;
return TRUE;
} else {
return FALSE;
}
#endif
}
void sk_getaddr(SockAddr addr, char *buf, int buflen)
{
if (addr->family == AF_UNSPEC) {
strncpy(buf, addr->hostname, buflen);
buf[buflen-1] = '\0';
} else {
#ifndef NO_IPV6
if (getnameinfo(addr->ai->ai_addr, addr->ai->ai_addrlen, buf, buflen,
NULL, 0, NI_NUMERICHOST) != 0) {
buf[0] = '\0';
strncat(buf, "<unknown>", buflen - 1);
}
#else
struct in_addr a;
assert(addr->family == AF_INET);
a.s_addr = htonl(addr->addresses[addr->curraddr]);
strncpy(buf, inet_ntoa(a), buflen);
buf[buflen-1] = '\0';
#endif
}
}
int sk_hostname_is_local(char *name)
{
return !strcmp(name, "localhost");
}
#define ipv4_is_loopback(addr) \
(((addr).s_addr & htonl(0xff000000)) == htonl(0x7f000000))
static int sockaddr_is_loopback(struct sockaddr *sa)
{
struct sockaddr_in *sin;
#ifndef NO_IPV6
struct sockaddr_in6 *sin6;
#endif
switch (sa->sa_family) {
case AF_INET:
sin = (struct sockaddr_in *)sa;
return ipv4_is_loopback(sin->sin_addr);
#ifndef NO_IPV6
case AF_INET6:
sin6 = (struct sockaddr_in6 *)sa;
return IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr);
#endif
case AF_UNIX:
return TRUE;
default:
return FALSE;
}
}
int sk_address_is_local(SockAddr addr)
{
if (addr->family == AF_UNSPEC)
return 0; /* we don't know; assume not */
else {
#ifndef NO_IPV6
return sockaddr_is_loopback(addr->ai->ai_addr);
#else
struct in_addr a;
assert(addr->family == AF_INET);
a.s_addr = htonl(addr->addresses[addr->curraddr]);
return ipv4_is_loopback(a);
#endif
}
}
int sk_addrtype(SockAddr addr)
{
return (addr->family == AF_INET ? ADDRTYPE_IPV4 :
#ifndef NO_IPV6
addr->family == AF_INET6 ? ADDRTYPE_IPV6 :
#endif
ADDRTYPE_NAME);
}
void sk_addrcopy(SockAddr addr, char *buf)
{
#ifndef NO_IPV6
if (addr->family == AF_INET)
memcpy(buf, &((struct sockaddr_in *)addr->ai->ai_addr)->sin_addr,
sizeof(struct in_addr));
else if (addr->family == AF_INET6)
memcpy(buf, &((struct sockaddr_in6 *)addr->ai->ai_addr)->sin6_addr,
sizeof(struct in6_addr));
else
assert(FALSE);
#else
struct in_addr a;
assert(addr->family == AF_INET);
a.s_addr = htonl(addr->addresses[addr->curraddr]);
memcpy(buf, (char*) &a.s_addr, 4);
#endif
}
void sk_addr_free(SockAddr addr)
{
#ifndef NO_IPV6
if (addr->ais != NULL)
freeaddrinfo(addr->ais);
#else
sfree(addr->addresses);
#endif
sfree(addr);
}
static Plug sk_tcp_plug(Socket sock, Plug p)
{
Actual_Socket s = (Actual_Socket) sock;
Plug ret = s->plug;
if (p)
s->plug = p;
return ret;
}
static void sk_tcp_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_tcp_close(Socket s);
static int sk_tcp_write(Socket s, const char *data, int len);
static int sk_tcp_write_oob(Socket s, const char *data, int len);
static void sk_tcp_set_private_ptr(Socket s, void *ptr);
static void *sk_tcp_get_private_ptr(Socket s);
static void sk_tcp_set_frozen(Socket s, int is_frozen);
static const char *sk_tcp_socket_error(Socket s);
static struct socket_function_table tcp_fn_table = {
sk_tcp_plug,
sk_tcp_close,
sk_tcp_write,
sk_tcp_write_oob,
sk_tcp_flush,
sk_tcp_set_private_ptr,
sk_tcp_get_private_ptr,
sk_tcp_set_frozen,
sk_tcp_socket_error
};
Socket sk_register(OSSocket sockfd, Plug plug)
{
Actual_Socket ret;
/*
* Create Socket structure.
*/
ret = snew(struct Socket_tag);
ret->fn = &tcp_fn_table;
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->frozen_readable = 0;
ret->localhost_only = 0; /* unused, but best init anyway */
ret->pending_error = 0;
ret->oobpending = FALSE;
ret->listener = 0;
ret->addr = NULL;
ret->connected = 1;
ret->s = sockfd;
if (ret->s < 0) {
ret->error = strerror(errno);
return (Socket) ret;
}
ret->oobinline = 0;
uxsel_tell(ret);
add234(sktree, ret);
return (Socket) ret;
}
static int try_connect(Actual_Socket sock)
{
int s;
#ifndef NO_IPV6
struct sockaddr_in6 a6;
#endif
struct sockaddr_in a;
struct sockaddr_un au;
const struct sockaddr *sa;
int err = 0;
short localport;
int fl, salen;
if (sock->s >= 0)
close(sock->s);
plug_log(sock->plug, 0, sock->addr, sock->port, NULL, 0);
/*
* Open socket.
*/
assert(sock->addr->family != AF_UNSPEC);
s = socket(sock->addr->family, SOCK_STREAM, 0);
sock->s = s;
if (s < 0) {
err = errno;
goto ret;
}
if (sock->oobinline) {
int b = TRUE;
setsockopt(s, SOL_SOCKET, SO_OOBINLINE, (void *) &b, sizeof(b));
}
if (sock->nodelay) {
int b = TRUE;
setsockopt(s, IPPROTO_TCP, TCP_NODELAY, (void *) &b, sizeof(b));
}
if (sock->keepalive) {
int b = TRUE;
setsockopt(s, SOL_SOCKET, SO_KEEPALIVE, (void *) &b, sizeof(b));
}
/*
* 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(&a,'\0',sizeof(struct sockaddr_in));
#ifndef NO_IPV6
memset(&a6,'\0',sizeof(struct sockaddr_in6));
#endif
/* 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(sock->addr->family != AF_UNIX) {
/* Loop round trying to bind */
while (1) {
int retcode;
#ifndef NO_IPV6
if (sock->addr->family == AF_INET6) {
/* XXX use getaddrinfo to get a local address? */
a6.sin6_family = AF_INET6;
a6.sin6_addr = in6addr_any;
a6.sin6_port = htons(localport);
retcode = bind(s, (struct sockaddr *) &a6, sizeof(a6));
} else
#endif
{
assert(sock->addr->family == AF_INET);
a.sin_family = AF_INET;
a.sin_addr.s_addr = htonl(INADDR_ANY);
a.sin_port = htons(localport);
retcode = bind(s, (struct sockaddr *) &a, sizeof(a));
}
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(sock->addr->family) {
#ifndef NO_IPV6
case AF_INET:
/* XXX would be better to have got getaddrinfo() to fill in the port. */
((struct sockaddr_in *)sock->addr->ai->ai_addr)->sin_port =
htons(sock->port);
sa = (const struct sockaddr *)sock->addr->ai->ai_addr;
salen = sock->addr->ai->ai_addrlen;
break;
case AF_INET6:
((struct sockaddr_in *)sock->addr->ai->ai_addr)->sin_port =
htons(sock->port);
sa = (const struct sockaddr *)sock->addr->ai->ai_addr;
salen = sock->addr->ai->ai_addrlen;
break;
#else
case AF_INET:
a.sin_family = AF_INET;
a.sin_addr.s_addr = htonl(sock->addr->addresses[sock->addr->curraddr]);
a.sin_port = htons((short) sock->port);
sa = (const struct sockaddr *)&a;
salen = sizeof a;
break;
#endif
case AF_UNIX:
assert(sock->port == 0); /* to catch confused people */
assert(strlen(sock->addr->hostname) < sizeof au.sun_path);
memset(&au, 0, sizeof au);
au.sun_family = AF_UNIX;
strcpy(au.sun_path, sock->addr->hostname);
sa = (const struct sockaddr *)&au;
salen = sizeof au;
break;
default:
assert(0 && "unknown address family");
exit(1); /* XXX: GCC doesn't understand assert() on some systems. */
}
fl = fcntl(s, F_GETFL);
if (fl != -1)
fcntl(s, F_SETFL, fl | O_NONBLOCK);
if ((connect(s, 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);
add234(sktree, sock);
ret:
if (err)
plug_log(sock->plug, 1, sock->addr, sock->port, strerror(err), err);
return err;
}
Socket sk_new(SockAddr addr, int port, int privport, int oobinline,
int nodelay, int keepalive, Plug plug)
{
Actual_Socket ret;
int err;
/*
* Create Socket structure.
*/
ret = snew(struct Socket_tag);
ret->fn = &tcp_fn_table;
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->frozen_readable = 0;
ret->localhost_only = 0; /* unused, but best init anyway */
ret->pending_error = 0;
ret->oobpending = FALSE;
ret->listener = 0;
ret->addr = addr;
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));
if (err)
ret->error = strerror(err);
return (Socket) ret;
}
Socket sk_newlistener(char *srcaddr, int port, Plug plug, int local_host_only, int address_family)
{
int s;
#ifndef NO_IPV6
struct addrinfo hints, *ai;
char portstr[6];
struct sockaddr_in6 a6;
#endif
struct sockaddr *addr;
int addrlen;
struct sockaddr_in a;
Actual_Socket ret;
int retcode;
int on = 1;
/*
* Create Socket structure.
*/
ret = snew(struct Socket_tag);
ret->fn = &tcp_fn_table;
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->frozen_readable = 0;
ret->localhost_only = local_host_only;
ret->pending_error = 0;
ret->oobpending = FALSE;
ret->listener = 1;
ret->addr = NULL;
/*
* Translate address_family from platform-independent constants
* into local reality.
*/
address_family = (address_family == ADDRTYPE_IPV4 ? AF_INET :
#ifndef NO_IPV6
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 (Socket) ret;
}
ret->oobinline = 0;
setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&on, sizeof(on));
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);
retcode = getaddrinfo(srcaddr, portstr, &hints, &ai);
if (retcode == 0) {
addr = ai->ai_addr;
addrlen = ai->ai_addrlen;
}
#else
memset(&a,'\0',sizeof(struct sockaddr_in));
a.sin_family = AF_INET;
a.sin_port = htons(port);
a.sin_addr.s_addr = inet_addr(srcaddr);
if (a.sin_addr.s_addr != (in_addr_t)(-1)) {
/* Override localhost_only with specified listen addr. */
ret->localhost_only = ipv4_is_loopback(a.sin_addr);
}
addr = (struct sockaddr *)&a;
addrlen = sizeof(a);
retcode = 0;
#endif
}
if (retcode != 0) {
#ifndef NO_IPV6
if (address_family == AF_INET6) {
memset(&a6,'\0',sizeof(struct sockaddr_in6));
a6.sin6_family = AF_INET6;
a6.sin6_port = htons(port);
if (local_host_only)
a6.sin6_addr = in6addr_loopback;
else
a6.sin6_addr = in6addr_any;
addr = (struct sockaddr *)&a6;
addrlen = sizeof(a6);
} else
#endif
{
memset(&a,'\0',sizeof(struct sockaddr_in));
a.sin_family = AF_INET;
a.sin_port = htons(port);
if (local_host_only)
a.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
else
a.sin_addr.s_addr = htonl(INADDR_ANY);
addr = (struct sockaddr *)&a;
addrlen = sizeof(a);
}
}
retcode = bind(s, addr, addrlen);
if (retcode < 0) {
close(s);
ret->error = strerror(errno);
return (Socket) ret;
}
if (listen(s, SOMAXCONN) < 0) {
close(s);
ret->error = strerror(errno);
return (Socket) ret;
}
ret->s = s;
uxsel_tell(ret);
add234(sktree, ret);
return (Socket) ret;
}
static void sk_tcp_close(Socket sock)
{
Actual_Socket s = (Actual_Socket) sock;
uxsel_del(s->s);
del234(sktree, s);
close(s->s);
if (s->addr)
sk_addr_free(s->addr);
sfree(s);
}
void *sk_getxdmdata(void *sock, int *lenp)
{
Actual_Socket s = (Actual_Socket) sock;
#ifdef NO_IPV6
struct sockaddr_in addr;
#else
struct sockaddr_storage addr;
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&addr;
#endif
struct sockaddr *sa = (struct sockaddr *)&addr;
struct sockaddr_in *sin = (struct sockaddr_in *)&addr;
socklen_t addrlen;
char *buf;
static unsigned int unix_addr = 0xFFFFFFFF;
/*
* We must check that this socket really _is_ an Actual_Socket.
*/
if (s->fn != &tcp_fn_table)
return NULL; /* failure */
addrlen = sizeof(addr);
if (getsockname(s->s, sa, &addrlen) < 0)
return NULL;
switch(sa->sa_family) {
case AF_INET:
*lenp = 6;
buf = snewn(*lenp, char);
PUT_32BIT_MSB_FIRST(buf, ntohl(sin->sin_addr.s_addr));
PUT_16BIT_MSB_FIRST(buf+4, ntohs(sin->sin_port));
break;
#ifndef NO_IPV6
case AF_INET6:
*lenp = 6;
buf = snewn(*lenp, char);
if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
memcpy(buf, sin6->sin6_addr.s6_addr + 12, 4);
PUT_16BIT_MSB_FIRST(buf+4, ntohs(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;
}
/*
* The function which tries to send on a socket once it's deemed
* writable.
*/
void try_send(Actual_Socket 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;
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);
}
}
}
uxsel_tell(s);
}
static int sk_tcp_write(Socket sock, const char *buf, int len)
{
Actual_Socket s = (Actual_Socket) sock;
/*
* 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_tcp_write_oob(Socket sock, const char *buf, int len)
{
Actual_Socket s = (Actual_Socket) sock;
/*
* 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 int net_select_result(int fd, int event)
{
int ret;
char buf[20480]; /* nice big buffer for plenty of speed */
Actual_Socket s;
u_long atmark;
/* Find the Socket structure */
s = find234(sktree, &fd, cmpforsearch);
if (!s)
return 1; /* 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) {
return 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;
}
return 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.
*/
#ifdef NO_IPV6
struct sockaddr_in ss;
#else
struct sockaddr_storage ss;
#endif
socklen_t addrlen = sizeof(ss);
int t; /* socket of connection */
memset(&ss, 0, addrlen);
t = accept(s->s, (struct sockaddr *)&ss, &addrlen);
if (t < 0) {
break;
}
if (s->localhost_only &&
!sockaddr_is_loopback((struct sockaddr *)&ss)) {
close(t); /* someone let nonlocal through?! */
} else if (plug_accepting(s->plug, t)) {
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) {
s->frozen_readable = 1;
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) {
/*
* An error at this point _might_ be an error reported
* by a non-blocking connect(). So before we return a
* panic status to the user, let's just see whether
* that's the case.
*/
int err = errno;
if (s->addr) {
plug_log(s->plug, 1, s->addr, s->port, strerror(err), err);
while (s->addr && sk_nextaddr(s->addr)) {
err = try_connect(s);
}
}
if (err != 0)
return plug_closing(s->plug, strerror(err), err, 0);
} else if (0 == ret) {
return 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;
}
return 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 connection is completed.
*/
s->connected = s->writable = 1;
uxsel_tell(s);
break;
} 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;
}
return 1;
}
/*
* Deal with socket errors detected in try_send().
*/
void net_pending_errors(void)
{
int i;
Actual_Socket s;
/*
* This might be a fiddly business, because it's just possible
* that handling a pending error on one socket might cause
* others to be closed. (I can't think of any reason this might
* happen in current SSH implementation, but to maintain
* generality of this network layer I'll assume the worst.)
*
* So what we'll do is search the socket list for _one_ socket
* with a pending error, and then handle it, and then search
* the list again _from the beginning_. Repeat until we make a
* pass with no socket errors present. That way we are
* protected against the socket list changing under our feet.
*/
do {
for (i = 0; (s = index234(sktree, i)) != NULL; i++) {
if (s->pending_error) {
/*
* An error has occurred on this socket. Pass it to the
* plug.
*/
plug_closing(s->plug, strerror(s->pending_error),
s->pending_error, 0);
break;
}
}
} while (s);
}
/*
* Each socket abstraction contains a `void *' private field in
* which the client can keep state.
*/
static void sk_tcp_set_private_ptr(Socket sock, void *ptr)
{
Actual_Socket s = (Actual_Socket) sock;
s->private_ptr = ptr;
}
static void *sk_tcp_get_private_ptr(Socket sock)
{
Actual_Socket s = (Actual_Socket) sock;
return s->private_ptr;
}
/*
* 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_tcp_socket_error(Socket sock)
{
Actual_Socket s = (Actual_Socket) sock;
return s->error;
}
static void sk_tcp_set_frozen(Socket sock, int is_frozen)
{
Actual_Socket s = (Actual_Socket) sock;
if (s->frozen == is_frozen)
return;
s->frozen = is_frozen;
if (!is_frozen && s->frozen_readable) {
char c;
recv(s->s, &c, 1, MSG_PEEK);
}
s->frozen_readable = 0;
uxsel_tell(s);
}
static void uxsel_tell(Actual_Socket s)
{
int rwx = 0;
if (s->listener) {
rwx |= 1; /* read == accept */
} else {
if (!s->connected)
rwx |= 2; /* write == connect */
if (s->connected && !s->frozen)
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;
}
SockAddr platform_get_x11_unix_address(int displaynum, char **canonicalname)
{
SockAddr ret = snew(struct SockAddr_tag);
int n;
memset(ret, 0, sizeof *ret);
ret->family = AF_UNIX;
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";
else
*canonicalname = dupstr(ret->hostname);
#ifndef NO_IPV6
ret->ais = NULL;
#else
ret->addresses = NULL;
#endif
return ret;
}
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