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/*
* src/socket.c
* socket functions
*
* YTalk
*
* Copyright (C) 1990,1992,1993 Britt Yenne
* Currently maintained by Andreas Kling
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include "header.h"
#include "menu.h"
#include "socket.h"
#include "mem.h"
#ifdef TIME_WITH_SYS_TIME
# include <sys/time.h>
# include <time.h>
#else
# ifdef HAVE_SYS_TIME
# include <sys/time.h>
# else
# include <time.h>
# endif
#endif
#ifdef HAVE_ARPA_INET_H
# include <arpa/inet.h>
#else
ylong inet_addr();
char *inet_ntoa();
#endif
#ifdef _AIX
# include <sys/select.h>
#endif
struct _talkd talkd[MAXDAEMON + 1];
int daemons = 0;
static int otalk, ntalk; /* daemon numbers */
static CTL_MSG omsg; /* old talk message */
static CTL_RESPONSE orsp; /* old talk response */
static CTL_MSG42 nmsg; /* new talk message */
static CTL_RESPONSE42 nrsp; /* new talk response */
static int autofd = -1; /* auto invite socket fd */
static struct sockaddr_in autosock; /* auto invite socket */
static ylong autoid[MAXDAEMON + 1]; /* auto invite seq numbers */
static ylong announce_id = 0; /* announce sequence id */
static readdr *readdr_list = NULL; /* list of re-addresses */
#define IN_ADDR(s) ((s).sin_addr.s_addr)
#define IN_PORT(s) ((s).sin_port)
#define SOCK_EQUAL(s,c) (IN_PORT(s) == IN_PORT(c) && IN_ADDR(s) == IN_ADDR(c))
/* ---- local functions ---- */
/*
* Create a datagram socket.
*/
static int
init_dgram(sock)
struct sockaddr_in *sock;
{
int fd;
socklen_t socklen;
sock->sin_family = AF_INET;
IN_ADDR(*sock) = INADDR_ANY;
IN_PORT(*sock) = 0;
if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
show_error("init_dgram: socket() failed");
bail(YTE_ERROR);
}
if (bind(fd, (struct sockaddr *) sock, sizeof(struct sockaddr_in)) != 0) {
close(fd);
show_error("init_dgram: bind() failed");
bail(YTE_ERROR);
}
socklen = sizeof(struct sockaddr_in);
if (getsockname(fd, (struct sockaddr *) sock, &socklen) < 0) {
close(fd);
show_error("init_dgram: getsockname() failed");
bail(YTE_ERROR);
}
IN_ADDR(*sock) = me->host_addr;
return fd;
}
/*
* Initialize a new daemon structure.
*/
static int
init_daemon(name, port, mptr, mlen, rptr, rlen)
char *name;
short port;
yaddr mptr, rptr;
int mlen, rlen;
{
struct servent *serv;
int d;
if (daemons >= MAXDAEMON) {
show_error("init_daemon: too many daemons");
bail(YTE_ERROR);
}
d = ++daemons; /* daemon number zero is not defined */
if ((serv = getservbyname(name, "udp")) != NULL)
talkd[d].port = serv->s_port;
else
talkd[d].port = port;
talkd[d].fd = init_dgram(&(talkd[d].sock));
talkd[d].mptr = mptr;
talkd[d].mlen = mlen;
talkd[d].rptr = rptr;
talkd[d].rlen = rlen;
return d;
}
static void
read_autoport(fd)
int fd;
{
socklen_t socklen;
v2_pack *pack;
char *estr;
struct sockaddr_in temp;
pack = get_mem(sizeof(v2_pack));
/* accept the connection */
socklen = sizeof(struct sockaddr_in);
if ((fd = accept(autofd, (struct sockaddr *) & temp, &socklen)) == -1) {
show_error("read_autoport: accept() failed");
free_mem(pack);
return;
}
/*
* The autoport socket just uses the old Ytalk version 2.? packet.
*/
errno = 0;
if (full_read(fd, (char *) pack, V2_PACKLEN) < 0 || pack->code != V2_AUTO) {
show_error("read_autoport: unknown auto-invite connection");
close(fd);
free_mem(pack);
return;
}
close(fd);
/* Make sure the name/host strings are properly terminated. */
pack->name[V2_NAMELEN - 1] = '\0';
pack->host[V2_HOSTLEN - 1] = '\0';
estr = get_mem(V2_NAMELEN + V2_HOSTLEN + 20);
if (!(def_flags & FL_INVITE)) {
#ifdef HAVE_SNPRINTF
snprintf(estr, V2_NAMELEN + V2_HOSTLEN + 20, "Talk to %s@%s?", pack->name, pack->host);
#else
sprintf(estr, "Talk to %s@%s?", pack->name, pack->host);
#endif
if (yes_no(estr) == 'n') {
free_mem(estr);
free_mem(pack);
return;
}
}
#ifdef HAVE_SNPRINTF
snprintf(estr, V2_NAMELEN + V2_HOSTLEN + 20, "%s@%s", pack->name, pack->host);
#else
sprintf(estr, "%s@%s", pack->name, pack->host);
#endif
(void) invite(estr, 1); /* we should be expected */
free_mem(estr);
free_mem(pack);
}
/*
* Create and initialize the auto-invitation socket.
*/
static void
init_autoport()
{
socklen_t socklen;
autosock.sin_family = AF_INET;
IN_ADDR(autosock) = INADDR_ANY;
IN_PORT(autosock) = 0;
if ((autofd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
show_error("init_autoport: socket() failed");
return;
}
if (bind(autofd, (struct sockaddr *) & autosock,
sizeof(struct sockaddr_in)) < 0) {
close(autofd);
autofd = -1;
show_error("init_autoport: bind() failed");
return;
}
socklen = sizeof(struct sockaddr_in);
if (getsockname(autofd, (struct sockaddr *) & autosock, &socklen) < 0) {
close(autofd);
autofd = -1;
show_error("init_autoport: getsockname() failed");
return;
}
IN_ADDR(autosock) = me->host_addr;
if (listen(autofd, 5) < 0) {
close(autofd);
autofd = -1;
show_error("init_autoport: listen() failed");
return;
}
memset(autoid, 0, (MAXDAEMON + 1) * sizeof(ylong));
add_fd(autofd, read_autoport);
}
/*
* Fill the socket address field with the appropriate return address for the
* host I'm sending to.
*/
static void
place_my_address(sock, addr)
BSD42_SOCK *sock;
register ylong addr;
{
register readdr *r;
for (r = readdr_list; r != NULL; r = r->next)
if (((r->from_addr & r->from_mask) == (me->host_addr & r->from_mask))
&& ((addr & r->mask) == r->addr)) {
addr = (r->id_addr & r->id_mask) |
(me->host_addr & (~(r->id_mask)));
IN_ADDR(*sock) = addr;
break;
}
if (r == NULL)
IN_ADDR(*sock) = me->host_addr;
sock->sin_family = htons(AF_INET);
}
/*
* sendit() sends the completed message to the talk daemon at the given
* hostname, then reads a response packet.
*/
static int
sendit(addr, d)
ylong addr; /* host internet address */
int d; /* daemon number */
{
ssize_t n;
struct sockaddr_in remote_daemon;
struct timeval tv;
char *rtype, *mtype;
fd_set sel;
/* set up the appropriate message structure */
if (d == ntalk) {
nmsg.vers = TALK_VERSION;
place_my_address(&(nmsg.ctl_addr), addr);
mtype = &(nmsg.type);
rtype = &(nrsp.type);
} else if (d == otalk) {
omsg.type = nmsg.type;
omsg.addr = nmsg.addr;
omsg.id_num = nmsg.id_num;
omsg.pid = nmsg.pid;
strncpy(omsg.l_name, nmsg.l_name, NAME_SIZE);
strncpy(omsg.r_name, nmsg.r_name, NAME_SIZE);
strncpy(omsg.r_tty, nmsg.r_tty, TTY_SIZE);
place_my_address(&(omsg.ctl_addr), addr);
mtype = &(omsg.type);
rtype = &(orsp.type);
} else {
#ifdef HAVE_SNPRINTF
snprintf(errstr, MAXERR, "Unknown daemon type: %d", d);
#else
sprintf(errstr, "Unknown daemon type: %d", d);
#endif
show_error(errstr);
return -1;
}
/* set up a sockaddr_in for the daemon we're sending to */
remote_daemon.sin_family = AF_INET;
IN_ADDR(remote_daemon) = addr;
IN_PORT(remote_daemon) = talkd[d].port;
/* flush any lingering input */
FD_ZERO(&sel);
for (;;) {
tv.tv_sec = 0L;
tv.tv_usec = 0L;
FD_SET(talkd[d].fd, &sel);
if ((n = select(talkd[d].fd + 1, &sel, 0, 0, &tv)) < 0) {
show_error("sendit: flush select() failed");
return -1;
}
if (n <= 0)
break;
if (recv(talkd[d].fd, talkd[d].rptr, talkd[d].rlen, 0) < 0) {
show_error("sendit: flush recv() failed");
return -1;
}
}
/*
* Now we need to send the actual packet. Due to unreliability of
* DGRAM sockets, we must resend the packet until we get a response
* from the server. Geez... two different daemons, both on
* unreliable sockets, and maybe even different daemons on different
* machines. Is *nothing* reliable anymore???
*/
do {
do {
n = sendto(talkd[d].fd, (char *) talkd[d].mptr, talkd[d].mlen,
0, (struct sockaddr *) & remote_daemon, sizeof(remote_daemon));
if (n != (ssize_t)talkd[d].mlen) {
show_error("sendit: sendto() failed");
return -1;
}
tv.tv_sec = 5L;
tv.tv_usec = 0L;
FD_SET(talkd[d].fd, &sel);
if ((n = select(talkd[d].fd + 1, &sel, 0, 0, &tv)) < 0) {
show_error("sendit: first select() failed");
return -1;
}
} while (n <= 0); /* ie: until we receive a reply */
do {
n = recv(talkd[d].fd, talkd[d].rptr, talkd[d].rlen, 0);
if (n < 0) {
show_error("sendit: recv() failed");
return -1;
}
if (*rtype != *mtype)
tv.tv_sec = 5L;
else
tv.tv_sec = 0L;
tv.tv_usec = 0L;
FD_SET(talkd[d].fd, &sel);
if ((n = select(talkd[d].fd + 1, &sel, 0, 0, &tv)) < 0) {
show_error("sendit: second select() failed");
return -1;
}
} while (n > 0 && *rtype != *mtype);
} while (*rtype != *mtype);
/* WHEW */
/*
* Just because a person is a SYSADMIN doesn't necessarily mean
* he/she knows everything about installing software. In fact, many
* have been known to install the talk daemon without setting the
* option required to pad out the structures so that "long"s are on
* four-byte boundaries on machines where "long"s can be on two-byte
* boundaries. This "bug" cost me about four hours of debugging to
* discover, so I'm not happy right now. Anyway, here's a quick hack
* to fix this problem.
*/
if (d == otalk && nrsp.type == LOOK_UP && nrsp.answer == 0) {
u_short t;
memcpy((char *) &t, ((char *) &orsp.addr.sin_family) - 2, sizeof(t));
if (ntohs(t) == AF_INET && ntohs(orsp.addr.sin_family) != AF_INET) {
char *c;
c = ((char *) &orsp) + sizeof(orsp) - 1;
for (; c >= (char *) &orsp.id_num; c--)
*c = *(c - 2);
}
}
/*
* Fill in the new talk response structure if we just read an old
* one.
*/
if (d == otalk) {
nrsp.type = orsp.type;
nrsp.answer = orsp.answer;
nrsp.id_num = orsp.id_num;
nrsp.addr = orsp.addr;
}
return 0;
}
/*
* find_daemon() locates the talk daemon(s) on a machine and determines what
* version(s) of the daemon are running.
*/
static int
find_daemon(addr)
ylong addr;
{
register hostinfo *h;
register int n, i, d;
CTL_MSG m1;
CTL_MSG42 m2;
struct sockaddr_in remote_daemon;
struct timeval tv;
int out, max;
fd_set sel;
static hostinfo *host_head = NULL;
/*
* If we've already used this host, look it up instead of blitting to
* the daemons again...
*/
for (h = host_head; h; h = h->next)
if (h->host_addr == addr)
return h->dtype;
remote_daemon.sin_family = AF_INET;
IN_ADDR(remote_daemon) = addr;
m1 = omsg;
m2 = nmsg;
/* m1.ctl_addr = talkd[otalk].sock; */
memcpy(&m1.ctl_addr, &talkd[otalk].sock, sizeof(m1.ctl_addr));
place_my_address(&(m1.ctl_addr), addr);
/* m2.ctl_addr = talkd[ntalk].sock; */
memcpy(&m2.ctl_addr, &talkd[ntalk].sock, sizeof(m2.ctl_addr));
place_my_address(&(m2.ctl_addr), addr);
m1.type = m2.type = LOOK_UP;
m1.id_num = m2.id_num = htonl(0);
m1.r_tty[0] = m2.r_tty[0] = '\0';
strcpy(m1.r_name, "ytalk");
strcpy(m2.r_name, "ytalk");
m1.addr.sin_family = m2.addr.sin_family = htons(AF_INET);
m1.ctl_addr.sin_family = m2.ctl_addr.sin_family = htons(AF_INET);
out = 0;
for (i = 0; i < 5; i++) {
IN_PORT(remote_daemon) = talkd[ntalk].port;
n = sendto(talkd[ntalk].fd, (char *) &m2, sizeof(m2),
0, (struct sockaddr *) & remote_daemon, sizeof(remote_daemon));
if (n != sizeof(m2))
show_error("Warning: cannot write to new talk daemon");
/* Commented out by J. Javier Maestro:
* Quick hack to make ytalk work for usernames longer than 8
* characters. Apparently, talkd returns an error message when
* receiving an old talk packet and this breaks ytalk.
*/
/*
IN_PORT(remote_daemon) = talkd[otalk].port;
n = sendto(talkd[otalk].fd, (char *) &m1, sizeof(m1),
0, (struct sockaddr *) & remote_daemon, sizeof(remote_daemon));
if (n != sizeof(m1))
show_error("Warning: cannot write to old talk daemon");
*/
tv.tv_sec = 4L;
tv.tv_usec = 0L;
FD_ZERO(&sel);
FD_SET(talkd[ntalk].fd, &sel);
FD_SET(talkd[otalk].fd, &sel);
max = talkd[ntalk].fd;
if (max < talkd[otalk].fd)
max = talkd[otalk].fd;
if ((n = select(1 + max, &sel, NULL, NULL, &tv)) < 0) {
show_error("find_daemon: first select() failed");
continue;
}
if (n == 0)
continue;
do {
for (d = 1; d <= daemons; d++)
if (FD_ISSET(talkd[d].fd, &sel)) {
int r;
r = recv(talkd[d].fd, errstr, talkd[d].rlen, 0);
if (r < 0) {
if (errno == EINTR || errno == ECONNREFUSED)
continue;
else
show_error("find_daemon: recv() failed");
}
out |= (1 << d);
}
tv.tv_sec = 0L;
tv.tv_usec = 500000L; /* give the other daemon a
* chance */
FD_ZERO(&sel);
FD_SET(talkd[ntalk].fd, &sel);
FD_SET(talkd[otalk].fd, &sel);
if ((n = select(1 + max, &sel, NULL, NULL, &tv)) < 0)
show_error("find_daemon: second select() failed");
} while (n > 0);
h = (hostinfo *) get_mem(sizeof(hostinfo));
h->next = host_head;
host_head = h;
h->host_addr = addr;
h->dtype = out;
if (out)
return out;
}
#ifdef HAVE_SNPRINTF
snprintf(errstr, MAXERR, "No talk daemon on %s", host_name(addr));
#else
sprintf(errstr, "No talk daemon on %s", host_name(addr));
#endif
show_error(errstr);
return 0;
}
static ylong
make_net_mask(addr)
ylong addr;
{
if (addr & (ylong) 0xff)
return (ylong) 0xffffffff;
if (addr & (ylong) 0xffff)
return (ylong) 0xffffff00;
if (addr & (ylong) 0xffffff)
return (ylong) 0xffff0000;
if (addr)
return (ylong) 0xff000000;
return (ylong) 0;
}
/* ---- global functions ---- */
/*
* Initialize sockets and message parameters.
*/
void
init_socket()
{
/* init daemons in order of preference */
ntalk = init_daemon("ntalk", 518, (yaddr)&nmsg, sizeof(nmsg),
(yaddr)&nrsp, sizeof(nrsp));
otalk = init_daemon("talk", 517, (yaddr)&omsg, sizeof(omsg),
(yaddr)&orsp, sizeof(orsp));
strncpy(nmsg.l_name, me->user_name, NTALK_NAME_SIZE);
/* omsg.ctl_addr = talkd[otalk].sock; */
/* nmsg.ctl_addr = talkd[ntalk].sock; */
memcpy(&omsg.ctl_addr, &talkd[otalk].sock, sizeof(omsg.ctl_addr));
memcpy(&nmsg.ctl_addr, &talkd[ntalk].sock, sizeof(nmsg.ctl_addr));
/* just in case */
omsg.ctl_addr.sin_family = nmsg.ctl_addr.sin_family = htons(AF_INET);
nmsg.vers = TALK_VERSION;
(void) find_daemon(me->host_addr);
if (!(def_flags & FL_NOAUTO))
init_autoport();
}
/*
* Close every open descriptor. This should only be used for a quick exit...
* it does not gracefully shut systems down.
*/
void
close_all()
{
register yuser *u;
register int d;
for (u = user_list; u; u = u->unext) {
if (u->fd > 0)
close(u->fd);
if (u->output_fd > 0)
close(u->output_fd);
}
if (autofd > 0)
close(autofd);
for (d = 1; d <= daemons; d++)
close(talkd[d].fd);
}
/*
* The following routines send a request across the DGRAM socket to the talk
* daemons.
*/
/*
* First, a quick and easy interface for the user sockets.
*/
int
send_dgram(user, type)
yuser *user;
u_char type;
{
ylong addr;
int d;
/* set up the message type and where to send it */
switch (type) {
case LEAVE_INVITE: /* leave an invite on my machine */
addr = me->host_addr;
nmsg.type = LEAVE_INVITE;
nmsg.id_num = htonl(user->l_id);
break;
case DELETE_INVITE: /* delete my invite on my machine */
addr = me->host_addr;
nmsg.type = DELETE;
nmsg.id_num = htonl(user->l_id);
break;
case ANNOUNCE: /* ring a user */
addr = user->host_addr;
nmsg.type = ANNOUNCE;
announce_id += 5; /* no guesswork here */
nmsg.id_num = htonl(announce_id);
break;
case LOOK_UP: /* look up remote invitation */
addr = user->host_addr;
nmsg.type = LOOK_UP;
nmsg.id_num = htonl(user->r_id);
break;
case DELETE: /* delete erroneous remote invitation */
addr = user->host_addr;
nmsg.type = DELETE;
nmsg.id_num = htonl(user->r_id);
break;
case AUTO_LOOK_UP: /* look up remote auto-invitation */
addr = user->host_addr;
nmsg.type = LOOK_UP;
nmsg.id_num = htonl(user->r_id);
break;
case AUTO_DELETE: /* delete erroneous remote auto-invitation */
addr = user->host_addr;
nmsg.type = DELETE;
nmsg.id_num = htonl(user->r_id);
break;
default:
errno = 0;
show_error("send_dgram: unknown type");
return -1;
}
/* find a common daemon, if possible */
if (user->daemon != 0)
d = user->daemon;
else {
int dtype, d1, d2;
/*
* Find the daemon(s) their host supports. If our two
* machines support a daemon in common, use that one. Else,
* normal UNIX "talk" is already screwed to the wall, but
* YTalk will at least work.
*/
d1 = find_daemon(user->host_addr);
d2 = find_daemon(me->host_addr);
dtype = d1 & d2;
if (d1 == 0 || d2 == 0)
return -1;
if (dtype == 0) {
dtype = find_daemon(addr);
for (d = 1; d <= daemons; d++)
if (dtype & (1 << d))
break;
if (d > daemons)
return -1;
} else {
for (d = 1; d <= daemons; d++)
if (dtype & (1 << d)) {
user->daemon = d;
break;
}
if (d > daemons)
return -1;
}
}
/*
* Each user has his own unique daemon id. Why? Tsch. Why. Well,
* the talk daemons consider two users equivalent if their usernames
* and machine names match. Hence, the daemons will not allow ytalk
* to talk with two different users with the same name on some
* machine. By assigning unique process id's, we trick the daemons
* into thinking we're several different users trying to talk to the
* same person. Sick? Don't blame me.
*/
nmsg.pid = htonl(user->d_id);
if (type == AUTO_LOOK_UP || type == AUTO_DELETE) {
strcpy(nmsg.l_name, "+AUTO"); /* put on my mask... */
strncpy(nmsg.r_name, user->user_name, NTALK_NAME_SIZE);
nmsg.r_tty[0] = '\0';
} else {
strncpy(nmsg.r_name, user->user_name, NTALK_NAME_SIZE);
strncpy(nmsg.r_tty, user->tty_name, TTY_SIZE);
}
/* nmsg.addr = user->sock; */
memcpy(&nmsg.addr, &user->sock, sizeof(nmsg.addr));
nmsg.addr.sin_family = htons(AF_INET);
if (sendit(addr, d) != 0) {
if (type == AUTO_LOOK_UP || type == AUTO_DELETE)
strncpy(nmsg.l_name, me->user_name, NTALK_NAME_SIZE);
return -2;
}
switch (type) {
case LEAVE_INVITE:
user->l_id = ntohl(nrsp.id_num);
break;
case LOOK_UP:
user->r_id = ntohl(nrsp.id_num);
break;
case AUTO_LOOK_UP:
strncpy(nmsg.l_name, me->user_name, NTALK_NAME_SIZE);
user->r_id = ntohl(nrsp.id_num);
break;
case AUTO_DELETE:
strncpy(nmsg.l_name, me->user_name, NTALK_NAME_SIZE);
break;
}
return nrsp.answer;
}
/*
* Next, an interface for the auto-invite socket. The auto-invite socket
* always sends to the caller's host, and always does just an invite.
*/
int
send_auto(type)
u_char type;
{
int dtype, d, rc;
if (autofd < 0)
return 0;
nmsg.type = type;
strcpy(nmsg.r_name, "+AUTO");
nmsg.r_tty[0] = '\0';
/* nmsg.addr = autosock; */
memcpy(&nmsg.addr, &autosock, sizeof(nmsg.addr));
nmsg.addr.sin_family = htons(AF_INET);
rc = 0;
dtype = find_daemon(me->host_addr);
for (d = daemons; d >= 1; d--)
if (dtype & (1 << d)) {
nmsg.id_num = htonl(autoid[d]);
nmsg.pid = htonl(1);
if (sendit(me->host_addr, d) < 0)
rc = -1;
else
autoid[d] = ntohl(nrsp.id_num);
}
if (rc)
return rc;
if (type == LEAVE_INVITE)
return 0;
return nrsp.answer;
}
/*
* Shut down the auto-invitation system.
*/
void
kill_auto()
{
if (autofd < 0)
return;
(void) send_auto(DELETE);
remove_fd(autofd);
close(autofd);
autofd = -1;
}
/*
* Create a TCP socket for communication with other talk users.
*/
int
newsock(user)
yuser *user;
{
int fd;
socklen_t socklen;
user->sock.sin_family = AF_INET;
IN_ADDR(user->sock) = INADDR_ANY;
IN_PORT(user->sock) = 0;
if ((fd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
show_error("newsock: socket() failed");
return -1;
}
if (bind(fd, (struct sockaddr *) & user->sock, sizeof(struct sockaddr_in)) < 0) {
close(fd);
show_error("newsock: bind() failed");
return -1;
}
socklen = sizeof(struct sockaddr_in);
if (getsockname(fd, (struct sockaddr *) & user->sock, &socklen) < 0) {
close(fd);
show_error("newsock: getsockname() failed");
return -1;
}
place_my_address((BSD42_SOCK *) &(user->sock), user->host_addr);
if (listen(fd, 5) < 0) {
close(fd);
show_error("newsock: listen() failed");
return -1;
}
user->fd = fd;
fd_to_user[user->fd] = user;
user->orig_sock = user->sock;
return 0;
}
/*
* Connect to another user's communication socket.
*/
int
connect_to(user)
yuser *user;
{
register yuser *u;
int fd;
socklen_t socklen;
struct sockaddr_in sock, orig_sock;
orig_sock = *(struct sockaddr_in *) & nrsp.addr;
orig_sock.sin_family = AF_INET;
/* it could be one of mine... */
for (u = user_list; u; u = u->unext)
if (SOCK_EQUAL(orig_sock, u->orig_sock))
return -3;
if (SOCK_EQUAL(orig_sock, autosock))
return -3;
sock = orig_sock;
if ((fd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
show_error("connect_to: socket() failed");
return -1;
}
if (connect(fd, (struct sockaddr *) & sock, sizeof(struct sockaddr_in)) < 0) {
close(fd);
if (errno == ECONNREFUSED) {
errno = 0;
return -2;
}
show_error("connect_to: connect() failed");
return -1;
}
socklen = sizeof(struct sockaddr_in);
if (getsockname(fd, (struct sockaddr *) & sock, &socklen) < 0) {
close(fd);
show_error("connect_to: getsockname() failed");
return -1;
}
if (user) {
user->sock = sock;
user->orig_sock = orig_sock;
user->fd = fd;
fd_to_user[user->fd] = user;
}
return fd;
}
/*
* Find a host's address.
*/
ylong
get_host_addr(hostname)
char *hostname;
{
struct hostent *host;
ylong addr;
errno = 0;
if ((host = (struct hostent *) gethostbyname(hostname)) != NULL) {
if (host->h_length != sizeof(addr)) {
#ifdef HAVE_SNPRINTF
snprintf(errstr, MAXERR, "Bad IN addr: %s", hostname);
#else
sprintf(errstr, "Bad IN addr: %s", hostname);
#endif
show_error(errstr);
return (ylong) -1;
}
memcpy(&addr, host->h_addr, sizeof(addr));
} else if ((addr = (ylong) inet_addr(hostname)) == (ylong) -1)
return (ylong) -1;
return addr;
}
/*
* Find a host name by host address. [19NOV96 Roger]: try to find the fqdn
* (1st alias with a dot)
*/
char *
host_name(addr)
ylong addr;
{
struct hostent *host;
char **s;
if ((host = gethostbyaddr((char *) &addr, sizeof(addr), AF_INET)) == NULL) {
struct in_addr tmp;
tmp.s_addr = addr;
return inet_ntoa(tmp);
}
if (strchr(host->h_name, '.'))
return (char *) host->h_name;
s = host->h_aliases;
if (s && *s)
for (; *s; s++)
if (strchr(*s, '.'))
return *s;
return (char *) host->h_name;
}
/*
* Re-address a given host ("from_id") to the given address or host id
* ("to_id") when communicating with some other host id ("on_id"). This is
* useful especially over routers where "foo.com" is known as the
* differently-addressed "bar.com" to host "xyzzy.com".
*/
void
readdress_host(from_id, to_id, on_id)
char *from_id, *to_id, *on_id;
{
register readdr *new;
ylong from_addr, to_addr, on_addr;
ylong from_mask, to_mask, on_mask;
if ((from_addr = get_host_addr(from_id)) == (ylong) -1) {
#ifdef HAVE_SNPRINTF
snprintf(errstr, MAXERR, "Unknown host: '%s'", from_id);
#else
sprintf(errstr, "Unknown host: '%s'", from_id);
#endif
show_error(errstr);
return;
}
if ((to_addr = get_host_addr(to_id)) == (ylong) -1) {
#ifdef HAVE_SNPRINTF
snprintf(errstr, MAXERR, "Unknown host: '%s'", to_id);
#else
sprintf(errstr, "Unknown host: '%s'", to_id);
#endif
show_error(errstr);
return;
}
if ((on_addr = get_host_addr(on_id)) == (ylong) -1) {
#ifdef HAVE_SNPRINTF
snprintf(errstr, MAXERR, "Unknown host: '%s'", on_id);
#else
sprintf(errstr, "Unknown host: '%s'", on_id);
#endif
show_error(errstr);
return;
}
from_mask = make_net_mask(from_addr);
to_mask = make_net_mask(to_addr);
on_mask = make_net_mask(on_addr);
#if 0
if ((from_addr & from_mask) != (me->host_addr & from_mask))
return;
#endif
if (from_addr == to_addr)
return;
new = (readdr *) get_mem(sizeof(readdr));
new->addr = on_addr;
new->mask = on_mask;
new->from_addr = from_addr;
new->from_mask = from_mask;
new->id_addr = to_addr;
new->id_mask = to_mask;
new->next = readdr_list;
readdr_list = new;
}
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