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Fix handling of dropped privileges; broken support for libwrap.

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hpa 2001-04-23 21:22:17 +00:00
parent 6f61e9935c
commit 87eda11da8
3 changed files with 49 additions and 15 deletions
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60
tftpd/tftpd.c
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@ -78,8 +78,11 @@ static const char *rcsid = "tftp-hpa $Id$";
#ifdef HAVE_TCPWRAPPERS
#include <tcpd.h>
int deny_severity = LOG_WARNING;
int allow_severity = LOG_INFO;
struct request_info wrap_request;
#endif
void bsd_signal(int, void (*)(int));
@ -150,7 +153,7 @@ struct options {
static void
usage(void)
{
syslog(LOG_ERR, "Usage: %s [-cs] [-r option...] [directory ...]",
syslog(LOG_ERR, "Usage: %s [-c] [-u user] [-r option...] [-s] [directory ...]",
__progname);
exit(1);
}
@ -168,10 +171,12 @@ main(int argc, char **argv)
int pid;
int i, j;
int c;
int setrv;
char *user = "nobody"; /* Default user */
openlog("tftpd", LOG_PID | LOG_NDELAY, LOG_DAEMON);
while ((c = getopt(argc, argv, "csr:")) != -1)
while ((c = getopt(argc, argv, "csu:r:")) != -1)
switch (c) {
case 'c':
cancreate = 1;
@ -179,6 +184,9 @@ main(int argc, char **argv)
case 's':
secure = 1;
break;
case 'u':
user = optarg;
break;
case 'r':
for ( opt = options ; opt->o_opt ; opt++ ) {
if ( !strcasecmp(optarg, opt->o_opt) ) {
@ -226,26 +234,17 @@ main(int argc, char **argv)
}
}
pw = getpwnam("nobody");
pw = getpwnam(user);
if (!pw) {
syslog(LOG_ERR, "no nobody: %m");
syslog(LOG_ERR, "no user %s: %m", user);
exit(1);
}
if (secure && chroot(".")) {
syslog(LOG_ERR, "chroot: %m");
exit(1);
}
(void) setegid(pw->pw_gid);
(void) setgid(pw->pw_gid);
(void) seteuid(pw->pw_uid);
(void) setuid(pw->pw_uid);
if (ioctl(fd, FIONBIO, &on) < 0) {
syslog(LOG_ERR, "ioctl(FIONBIO): %m");
exit(1);
}
fromlen = sizeof (from);
n = myrecvfrom(fd, buf, sizeof (buf), 0,
(struct sockaddr *)&from, &fromlen,
@ -258,10 +257,41 @@ main(int argc, char **argv)
#ifdef HAVE_TCPWRAPPERS
/* Verify if this was a legal request for us. */
if ( hosts_ctl("tftp", STRING_UNKNOWN, inet_ntoa(from.sin_addr), STRING_UNKNOWN) == 0 )
request_init(&wrap_request,
RQ_DAEMON, "tftpd",
RQ_FILE, fd,
RQ_CLIENT_SIN, &from,
RQ_SERVER_SIN, &myaddr,
0);
if ( hosts_access(wrap_request) == 0 )
exit(1); /* Access denied */
#endif
/* Drop privileges */
if (secure && chroot(".")) {
syslog(LOG_ERR, "chroot: %m");
exit(1);
}
#ifdef HAVE_SETREGID
setrv = setregid(pw->pw_gid, pw->pw_gid);
#else
setrv = setegid(pw->pw_gid) || setgid(pw->pw_gid);
#endif
#ifdef HAVE_SETREUID
setrv = setrv || setreuid(pw->pw_uid, pw->pw_uid);
#else
/* Important: setuid() must come first */
setrv = setrv || setuid(pw->pw_uid) ||
(geteuid() != pw->pw_uid && seteuid(pw->pw_uid));
#endif
if ( setrv ) {
syslog(LOG_ERR, "cannot drop privileges: %m");
exit(1);
}
/*
* Now that we have read the message out of the UDP
* socket, we fork and exit. Thus, inetd will go back