freebsd-dev/libexec/fingerd/fingerd.c
Colin Percival f9bcf9cabf Mark functions as __dead2 in order to help the LLVM static checker
understand which code paths aren't possible.

This commit eliminates 117 false positive bug reports of the form
"allocate memory; error out if pointer is NULL; use pointer".
2008-08-04 01:25:48 +00:00

222 lines
5.5 KiB
C

/*
* Copyright (c) 1983, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1983, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
#if 0
static char sccsid[] = "@(#)fingerd.c 8.1 (Berkeley) 6/4/93";
#endif
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <errno.h>
#include <unistd.h>
#include <syslog.h>
#include <libutil.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "pathnames.h"
void logerr(const char *, ...) __printflike(1, 2) __dead2;
int
main(int argc, char *argv[])
{
FILE *fp;
int ch;
char *lp;
struct sockaddr_storage ss;
socklen_t sval;
int p[2], logging, pflag, secure;
#define ENTRIES 50
char **ap, *av[ENTRIES + 1], **comp, line[1024], *prog;
char rhost[MAXHOSTNAMELEN];
prog = _PATH_FINGER;
logging = pflag = secure = 0;
openlog("fingerd", LOG_PID | LOG_CONS, LOG_DAEMON);
opterr = 0;
while ((ch = getopt(argc, argv, "lp:s")) != -1)
switch (ch) {
case 'l':
logging = 1;
break;
case 'p':
prog = optarg;
pflag = 1;
break;
case 's':
secure = 1;
break;
case '?':
default:
logerr("illegal option -- %c", optopt);
}
/*
* Enable server-side Transaction TCP.
*/
{
int one = 1;
if (setsockopt(STDOUT_FILENO, IPPROTO_TCP, TCP_NOPUSH, &one,
sizeof one) < 0) {
logerr("setsockopt(TCP_NOPUSH) failed: %m");
}
}
if (!fgets(line, sizeof(line), stdin))
exit(1);
if (logging || pflag) {
sval = sizeof(ss);
if (getpeername(0, (struct sockaddr *)&ss, &sval) < 0)
logerr("getpeername: %s", strerror(errno));
realhostname_sa(rhost, sizeof rhost - 1,
(struct sockaddr *)&ss, sval);
rhost[sizeof(rhost) - 1] = '\0';
if (pflag)
setenv("FINGERD_REMOTE_HOST", rhost, 1);
}
if (logging) {
char *t;
char *end;
end = memchr(line, 0, sizeof(line));
if (end == NULL) {
if ((t = malloc(sizeof(line) + 1)) == NULL)
logerr("malloc: %s", strerror(errno));
memcpy(t, line, sizeof(line));
t[sizeof(line)] = 0;
} else {
if ((t = strdup(line)) == NULL)
logerr("strdup: %s", strerror(errno));
}
for (end = t; *end; end++)
if (*end == '\n' || *end == '\r')
*end = ' ';
syslog(LOG_NOTICE, "query from %s: `%s'", rhost, t);
}
comp = &av[1];
av[2] = "--";
for (lp = line, ap = &av[3];;) {
*ap = strtok(lp, " \t\r\n");
if (!*ap) {
if (secure && ap == &av[3]) {
puts("must provide username\r\n");
exit(1);
}
break;
}
if (secure && strchr(*ap, '@')) {
puts("forwarding service denied\r\n");
exit(1);
}
/* RFC742: "/[Ww]" == "-l" */
if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) {
av[1] = "-l";
comp = &av[0];
}
else if (++ap == av + ENTRIES) {
*ap = NULL;
break;
}
lp = NULL;
}
if ((lp = strrchr(prog, '/')) != NULL)
*comp = ++lp;
else
*comp = prog;
if (pipe(p) < 0)
logerr("pipe: %s", strerror(errno));
switch(vfork()) {
case 0:
(void)close(p[0]);
if (p[1] != STDOUT_FILENO) {
(void)dup2(p[1], STDOUT_FILENO);
(void)close(p[1]);
}
dup2(STDOUT_FILENO, STDERR_FILENO);
execv(prog, comp);
write(STDERR_FILENO, prog, strlen(prog));
#define MSG ": cannot execute\n"
write(STDERR_FILENO, MSG, strlen(MSG));
#undef MSG
_exit(1);
case -1:
logerr("fork: %s", strerror(errno));
}
(void)close(p[1]);
if (!(fp = fdopen(p[0], "r")))
logerr("fdopen: %s", strerror(errno));
while ((ch = getc(fp)) != EOF) {
if (ch == '\n')
putchar('\r');
putchar(ch);
}
exit(0);
}
#include <stdarg.h>
void
logerr(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
(void)vsyslog(LOG_ERR, fmt, ap);
va_end(ap);
exit(1);
/* NOTREACHED */
}