github
/
putty
зеркало из https://github.com/github/putty.git
1
0
Форкнуть 0
Код Задачи Пакеты Проекты Релизы Вики Активность
putty/unix/uxnet.c

1055 строки
25 KiB
C
Исходник Ответственный История

/*
* 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>
#define DEFINE_PLUG_METHOD_MACROS
#include "putty.h"
#include "network.h"
#include "tree234.h"
#define ipv4_is_loopback(addr) (inet_netof(addr) == IN_LOOPBACKNET)
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;
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;
};
/*
* 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;
#ifdef IPV6
struct addrinfo *ai; /* Address IPv6 style. */
#else
unsigned long address; /* Address IPv4 style. */
#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);
}
}
}
const char *error_string(int error)
{
return strerror(error);
}
SockAddr sk_namelookup(const char *host, char **canonicalname)
{
SockAddr ret = snew(struct SockAddr_tag);
#ifdef IPV6
struct addrinfo hints;
int err;
#else
unsigned long a;
struct hostent *h = NULL;
#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;
#ifdef IPV6
hints.ai_flags = AI_CANONNAME;
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = 0;
hints.ai_protocol = 0;
hints.ai_addrlen = 0;
hints.ai_addr = NULL;
hints.ai_canonname = NULL;
hints.ai_next = NULL;
err = getaddrinfo(host, NULL, NULL, &ret->ai);
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) INADDR_NONE) {
/*
* 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;
}
memcpy(&a, h->h_addr, sizeof(a));
/* This way we are always sure the h->h_name is valid :) */
strncpy(realhost, h->h_name, sizeof(realhost));
} 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->address = 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->family = AF_UNSPEC;
strncpy(ret->hostname, host, lenof(ret->hostname));
ret->hostname[lenof(ret->hostname)-1] = '\0';
return ret;
}
void sk_getaddr(SockAddr addr, char *buf, int buflen)
{
if (addr->family == AF_UNSPEC) {
strncpy(buf, addr->hostname, buflen);
buf[buflen-1] = '\0';
} else {
#ifdef 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->address);
strncpy(buf, inet_ntoa(a), buflen);
buf[buflen-1] = '\0';
#endif
}
}
int sk_hostname_is_local(char *name)
{
return !strcmp(name, "localhost");
}
int sk_address_is_local(SockAddr addr)
{
if (addr->family == AF_UNSPEC)
return 0; /* we don't know; assume not */
else {
#ifdef IPV6
if (addr->family == AF_INET)
return ipv4_is_loopback(
((struct sockaddr_in *)addr->ai->ai_addr)->sin_addr);
else if (addr->family == AF_INET6)
return IN6_IS_ADDR_LOOPBACK(
&((struct sockaddr_in6 *)addr->ai->ai_addr)->sin6_addr);
else
return 0;
#else
struct in_addr a;
assert(addr->family == AF_INET);
a.s_addr = htonl(addr->address);
return ipv4_is_loopback(a);
#endif
}
}
int sk_addrtype(SockAddr addr)
{
return (addr->family == AF_INET ? ADDRTYPE_IPV4 :
#ifdef IPV6
addr->family == AF_INET6 ? ADDRTYPE_IPV6 :
#endif
ADDRTYPE_NAME);
}
void sk_addrcopy(SockAddr addr, char *buf)
{
#ifdef 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->address);
memcpy(buf, (char*) &a.s_addr, 4);
#endif
}
void sk_addr_free(SockAddr addr)
{
#ifdef IPV6
if (addr->ai != NULL)
freeaddrinfo(addr->ai);
#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->s = sockfd;
if (ret->s < 0) {
ret->error = error_string(errno);
return (Socket) ret;
}
ret->oobinline = 0;
uxsel_tell(ret);
add234(sktree, ret);
return (Socket) ret;
}
Socket sk_new(SockAddr addr, int port, int privport, int oobinline,
int nodelay, Plug plug)
{
int s;
#ifdef IPV6
struct sockaddr_in6 a6;
#endif
struct sockaddr_in a;
int err;
Actual_Socket ret;
short localport;
int fl;
/*
* 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;
/*
* Open socket.
*/
assert(addr->family != AF_UNSPEC);
s = socket(addr->family, SOCK_STREAM, 0);
ret->s = s;
if (s < 0) {
ret->error = error_string(errno);
return (Socket) ret;
}
ret->oobinline = oobinline;
if (oobinline) {
int b = TRUE;
setsockopt(s, SOL_SOCKET, SO_OOBINLINE, (void *) &b, sizeof(b));
}
if (nodelay) {
int b = TRUE;
setsockopt(s, IPPROTO_TCP, TCP_NODELAY, (void *) &b, sizeof(b));
}
/*
* Bind to local address.
*/
if (privport)
localport = 1023; /* count from 1023 downwards */
else
localport = 0; /* just use port 0 (ie kernel picks) */
/* Loop round trying to bind */
while (1) {
int retcode;
#ifdef IPV6
if (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(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) {
ret->error = error_string(err);
return (Socket) ret;
}
/*
* Connect to remote address.
*/
#ifdef IPV6
/* XXX would be better to have got getaddrinfo() to fill in the port. */
if (addr->family == AF_INET)
((struct sockaddr_in *)addr->ai->ai_addr)->sin_port =
htons(port);
else {
assert(addr->family == AF_INET6);
((struct sockaddr_in *)addr->ai->ai_addr)->sin_port =
htons(port);
}
#else
a.sin_family = AF_INET;
a.sin_addr.s_addr = htonl(addr->address);
a.sin_port = htons((short) port);
#endif
fl = fcntl(s, F_GETFL);
if (fl != -1)
fcntl(s, F_SETFL, fl | O_NONBLOCK);
if ((
#ifdef IPV6
connect(s, addr->ai->ai_addr, addr->ai->ai_addrlen)
#else
connect(s, (struct sockaddr *) &a, sizeof(a))
#endif
) < 0) {
if ( errno != EINPROGRESS ) {
ret->error = error_string(errno);
return (Socket) ret;
}
} else {
/*
* If we _don't_ get EWOULDBLOCK, the connect has completed
* and we should set the socket as connected and writable.
*/
ret->connected = 1;
ret->writable = 1;
}
uxsel_tell(ret);
add234(sktree, ret);
sk_addr_free(addr);
return (Socket) ret;
}
Socket sk_newlistener(char *srcaddr, int port, Plug plug, int local_host_only)
{
int s;
#ifdef IPV6
#if 0
struct sockaddr_in6 a6;
#endif
struct addrinfo hints, *ai;
char portstr[6];
#endif
struct sockaddr_in a;
int err;
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;
/*
* Open socket.
*/
s = socket(AF_INET, SOCK_STREAM, 0);
ret->s = s;
if (s < 0) {
ret->error = error_string(errno);
return (Socket) ret;
}
ret->oobinline = 0;
setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&on, sizeof(on));
#ifdef IPV6
hints.ai_flags = AI_NUMERICHOST;
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = 0;
hints.ai_protocol = 0;
hints.ai_addrlen = 0;
hints.ai_addr = NULL;
hints.ai_canonname = NULL;
hints.ai_next = NULL;
sprintf(portstr, "%d", port);
if (srcaddr != NULL && getaddrinfo(srcaddr, portstr, &hints, &ai) == 0)
retcode = bind(s, ai->ai_addr, ai->ai_addrlen);
else
#if 0
{
/*
* FIXME: Need two listening sockets, in principle, one for v4
* and one for v6
*/
if (local_host_only)
a6.sin6_addr = in6addr_loopback;
else
a6.sin6_addr = in6addr_any;
a6.sin6_port = htons(port);
} else
#endif
#endif
{
int got_addr = 0;
a.sin_family = AF_INET;
/*
* Bind to source address. First try an explicitly
* specified one...
*/
if (srcaddr) {
a.sin_addr.s_addr = inet_addr(srcaddr);
if (a.sin_addr.s_addr != INADDR_NONE) {
/* Override localhost_only with specified listen addr. */
ret->localhost_only = ipv4_is_loopback(a.sin_addr);
got_addr = 1;
}
}
/*
* ... and failing that, go with one of the standard ones.
*/
if (!got_addr) {
if (local_host_only)
a.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
else
a.sin_addr.s_addr = htonl(INADDR_ANY);
}
a.sin_port = htons((short)port);
retcode = bind(s, (struct sockaddr *) &a, sizeof(a));
}
if (retcode >= 0) {
err = 0;
} else {
err = errno;
}
if (err) {
ret->error = error_string(err);
return (Socket) ret;
}
if (listen(s, SOMAXCONN) < 0) {
close(s);
ret->error = error_string(errno);
return (Socket) ret;
}
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);
sfree(s);
}
int sk_getxdmdata(void *sock, unsigned long *ip, int *port)
{
Actual_Socket s = (Actual_Socket) sock;
struct sockaddr_in addr;
socklen_t addrlen;
/*
* We must check that this socket really _is_ an Actual_Socket.
*/
if (s->fn != &tcp_fn_table)
return 0; /* failure */
/*
* If we ever implement connecting to a local X server through
* a Unix socket, we return 0xFFFFFFFF for the IP address and
* our current pid for the port. Bizarre, but such is life.
*/
addrlen = sizeof(addr);
if (getsockname(s->s, (struct sockaddr *)&addr, &addrlen) < 0 ||
addr.sin_family != AF_INET)
return 0;
*ip = ntohl(addr.sin_addr.s_addr);
*port = ntohs(addr.sin_port);
return 1;
}
/*
* 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 if (nsent == 0 ||
err == ECONNABORTED || err == ECONNRESET) {
/*
* If send() returns CONNABORTED or CONNRESET, 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 {
/* We're inside the Unix frontend here, so we know
* that the frontend handle is unnecessary. */
logevent(NULL, error_string(err));
fatalbox("%s", error_string(err));
}
} 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;
int err;
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) {
const char *str = (ret == 0 ? "Internal networking trouble" :
error_string(errno));
/* We're inside the Unix frontend here, so we know
* that the frontend handle is unnecessary. */
logevent(NULL, str);
fatalbox("%s", str);
} else {
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.
*/
struct sockaddr_in isa;
int addrlen = sizeof(struct sockaddr_in);
int t; /* socket of connection */
memset(&isa, 0, sizeof(struct sockaddr_in));
err = 0;
t = accept(s->s,(struct sockaddr *)&isa,&addrlen);
if (t < 0) {
break;
}
if (s->localhost_only && !ipv4_is_loopback(isa.sin_addr)) {
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) {
return plug_closing(s->plug, error_string(errno), errno, 0);
} else if (0 == ret) {
return plug_closing(s->plug, NULL, 0, 0);
} else {
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, error_string(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->connected)
rwx |= 2; /* write == connect */
if (s->connected && !s->frozen)
rwx |= 1 | 4; /* read, except */
if (bufchain_size(&s->output_data))
rwx |= 2; /* write */
if (s->listener)
rwx |= 1; /* read == accept */
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;
}
Ссылка в новой задаче Показать git blame Копировать постоянную ссылку