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inetd: close new udp fd in "udp nowait" case

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Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2011-09-11 16:48:21 +02:00
parent d2fe2ba08d
commit 223b9417b3
1 changed files with 55 additions and 11 deletions
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66
networking/inetd.c
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@ -357,10 +357,26 @@ struct BUG_G_too_big {
config_filename = "/etc/inetd.conf"; \
} while (0)
#if 1
# define dbg(...) ((void)0)
#else
# define dbg(...) \
do { \
int dbg_fd = open("inetd_debug.log", O_WRONLY | O_CREAT | O_APPEND, 0666); \
if (dbg_fd >= 0) { \
fdprintf(dbg_fd, "%d: ", getpid()); \
fdprintf(dbg_fd, __VA_ARGS__); \
close(dbg_fd); \
} \
} while (0)
#endif
static void maybe_close(int fd)
{
if (fd >= 0)
if (fd >= 0) {
close(fd);
dbg("closed fd:%d\n", fd);
}
}
// TODO: move to libbb?
@ -464,7 +480,9 @@ static void remove_fd_from_set(int fd)
{
if (fd >= 0) {
FD_CLR(fd, &allsock);
dbg("stopped listening on fd:%d\n", fd);
maxsock = -1;
dbg("maxsock:%d\n", maxsock);
}
}
@ -472,8 +490,10 @@ static void add_fd_to_set(int fd)
{
if (fd >= 0) {
FD_SET(fd, &allsock);
dbg("started listening on fd:%d\n", fd);
if (maxsock >= 0 && fd > maxsock) {
prev_maxsock = maxsock = fd;
dbg("maxsock:%d\n", maxsock);
if ((rlim_t)fd > rlim_ofile_cur - FD_MARGIN)
bump_nofile();
}
@ -492,6 +512,7 @@ static void recalculate_maxsock(void)
maxsock = fd;
fd++;
}
dbg("recalculated maxsock:%d\n", maxsock);
prev_maxsock = maxsock;
if ((rlim_t)maxsock > rlim_ofile_cur - FD_MARGIN)
bump_nofile();
@ -549,8 +570,13 @@ static void prepare_socket_fd(servtab_t *sep)
rearm_alarm();
return;
}
if (sep->se_socktype == SOCK_STREAM)
if (sep->se_socktype == SOCK_STREAM) {
listen(fd, global_queuelen);
dbg("new sep->se_fd:%d (stream)\n", fd);
} else {
dbg("new sep->se_fd:%d (!stream)\n", fd);
}
add_fd_to_set(fd);
sep->se_fd = fd;
@ -1012,7 +1038,7 @@ static void reread_config_file(int sig UNUSED_PARAM)
* new config file doesnt have them. */
block_CHLD_HUP_ALRM(&omask);
sepp = &serv_list;
while ((sep = *sepp)) {
while ((sep = *sepp) != NULL) {
if (sep->se_checked) {
sepp = &sep->se_next;
continue;
@ -1206,11 +1232,13 @@ int inetd_main(int argc UNUSED_PARAM, char **argv)
}
continue;
}
dbg("ready_fd_cnt:%d\n", ready_fd_cnt);
for (sep = serv_list; ready_fd_cnt && sep; sep = sep->se_next) {
if (sep->se_fd == -1 || !FD_ISSET(sep->se_fd, &readable))
continue;
dbg("ready fd:%d\n", sep->se_fd);
ready_fd_cnt--;
ctrl = sep->se_fd;
accepted_fd = -1;
@ -1218,6 +1246,7 @@ int inetd_main(int argc UNUSED_PARAM, char **argv)
if (!sep->se_wait) {
if (sep->se_socktype == SOCK_STREAM) {
ctrl = accepted_fd = accept(sep->se_fd, NULL, NULL);
dbg("accepted_fd:%d\n", accepted_fd);
if (ctrl < 0) {
if (errno != EINTR)
bb_perror_msg("accept (for %s)", sep->se_service);
@ -1238,19 +1267,22 @@ int inetd_main(int argc UNUSED_PARAM, char **argv)
* (can create many copies of same child, etc).
* Parent must create and use new socket instead. */
new_udp_fd = socket(sep->se_family, SOCK_DGRAM, 0);
dbg("new_udp_fd:%d\n", new_udp_fd);
if (new_udp_fd < 0) { /* error: eat packet, forget about it */
udp_err:
recv(sep->se_fd, line, LINE_SIZE, MSG_DONTWAIT);
continue;
}
setsockopt_reuseaddr(new_udp_fd);
/* TODO: better do bind after vfork in parent,
/* TODO: better do bind after fork in parent,
* so that we don't have two wildcard bound sockets
* even for a brief moment? */
if (bind(new_udp_fd, &sep->se_lsa->u.sa, sep->se_lsa->len) < 0) {
dbg("bind(new_udp_fd) failed\n");
close(new_udp_fd);
goto udp_err;
}
dbg("bind(new_udp_fd) succeeded\n");
}
}
@ -1278,6 +1310,7 @@ int inetd_main(int argc UNUSED_PARAM, char **argv)
sep->se_count = 0;
rearm_alarm(); /* will revive it in RETRYTIME sec */
restore_sigmask(&omask);
maybe_close(new_udp_fd);
maybe_close(accepted_fd);
continue; /* -> check next fd in fd set */
}
@ -1298,17 +1331,18 @@ int inetd_main(int argc UNUSED_PARAM, char **argv)
bb_perror_msg("vfork"+1);
sleep(1);
restore_sigmask(&omask);
maybe_close(new_udp_fd);
maybe_close(accepted_fd);
continue; /* -> check next fd in fd set */
}
if (pid == 0)
pid--; /* -1: "we did fork and we are child" */
}
/* if pid == 0 here, we never forked */
/* if pid == 0 here, we didn't fork */
if (pid > 0) { /* parent */
if (sep->se_wait) {
/* tcp wait: we passed listening socket to child,
/* wait: we passed socket to child,
* will wait for child to terminate */
sep->se_wait = pid;
remove_fd_from_set(sep->se_fd);
@ -1317,17 +1351,19 @@ int inetd_main(int argc UNUSED_PARAM, char **argv)
/* udp nowait: child connected the socket,
* we created and will use new, unconnected one */
xmove_fd(new_udp_fd, sep->se_fd);
dbg("moved new_udp_fd:%d to sep->se_fd:%d\n", new_udp_fd, sep->se_fd);
}
restore_sigmask(&omask);
maybe_close(accepted_fd);
continue; /* -> check next fd in fd set */
}
/* we are either child or didn't vfork at all */
/* we are either child or didn't fork at all */
#ifdef INETD_BUILTINS_ENABLED
if (sep->se_builtin) {
if (pid) { /* "pid" is -1: we did vfork */
if (pid) { /* "pid" is -1: we did fork */
close(sep->se_fd); /* listening socket */
dbg("closed sep->se_fd:%d\n", sep->se_fd);
logmode = LOGMODE_NONE; /* make xwrite etc silent */
}
restore_sigmask(&omask);
@ -1335,7 +1371,7 @@ int inetd_main(int argc UNUSED_PARAM, char **argv)
sep->se_builtin->bi_stream_fn(ctrl, sep);
else
sep->se_builtin->bi_dgram_fn(ctrl, sep);
if (pid) /* we did vfork */
if (pid) /* we did fork */
_exit(EXIT_FAILURE);
maybe_close(accepted_fd);
continue; /* -> check next fd in fd set */
@ -1345,9 +1381,14 @@ int inetd_main(int argc UNUSED_PARAM, char **argv)
setsid();
/* "nowait" udp */
if (new_udp_fd >= 0) {
len_and_sockaddr *lsa = xzalloc_lsa(sep->se_family);
len_and_sockaddr *lsa;
int r;
close(new_udp_fd);
dbg("closed new_udp_fd:%d\n", new_udp_fd);
lsa = xzalloc_lsa(sep->se_family);
/* peek at the packet and remember peer addr */
int r = recvfrom(ctrl, NULL, 0, MSG_PEEK|MSG_DONTWAIT,
r = recvfrom(ctrl, NULL, 0, MSG_PEEK|MSG_DONTWAIT,
&lsa->u.sa, &lsa->len);
if (r < 0)
goto do_exit1;
@ -1355,6 +1396,7 @@ int inetd_main(int argc UNUSED_PARAM, char **argv)
* only packets from this peer will be recv'ed,
* and bare write()/send() will work on it */
connect(ctrl, &lsa->u.sa, lsa->len);
dbg("connected ctrl:%d to remote peer\n", ctrl);
free(lsa);
}
/* prepare env and exec program */
@ -1391,6 +1433,7 @@ int inetd_main(int argc UNUSED_PARAM, char **argv)
*/
xmove_fd(ctrl, STDIN_FILENO);
xdup2(STDIN_FILENO, STDOUT_FILENO);
dbg("moved ctrl:%d to fd 0,1[,2]\n", ctrl);
/* manpages of inetd I managed to find either say
* that stderr is also redirected to the network,
* or do not talk about redirection at all (!) */
@ -1403,6 +1446,7 @@ int inetd_main(int argc UNUSED_PARAM, char **argv)
maybe_close(sep2->se_fd);
sigaction_set(SIGPIPE, &saved_pipe_handler);
restore_sigmask(&omask);
dbg("execing:'%s'\n", sep->se_program);
BB_EXECVP(sep->se_program, sep->se_argv);
bb_perror_msg("can't execute '%s'", sep->se_program);
do_exit1: