telnetd: don't exit if waitpid() returns 0.
Noticed while using telnetd to manually test some telnet fixes: telnetd
would sometimes exit when I'd disconnect because it couldn't find pid 0
on its list of sessions.
I've not seen obscure exits because select() times out, but I've also
changed that `return` to an error_exit() so we'll at least know what's
happened if that ever occurs.
Also use <arpa/telnet.h> rather than manually #define'ing its constants,
use the FLAG() macro throughout, and xsetsockopt(). Don't pointlessly
set errno to 0 at the start of main and then never look at it again.
diff --git a/toys/pending/telnetd.c b/toys/pending/telnetd.c
index bb08e78..c82ff61 100644
--- a/toys/pending/telnetd.c
+++ b/toys/pending/telnetd.c
@@ -24,7 +24,9 @@
#define FOR_telnetd
#include "toys.h"
+#include <arpa/telnet.h>
#include <utmp.h>
+
GLOBALS(
char *login_path;
char *issue_path;
@@ -36,20 +38,6 @@
pid_t fork_pid;
)
-
-# define IAC 255 /* interpret as command: */
-# define DONT 254 /* you are not to use option */
-# define DO 253 /* please, you use option */
-# define WONT 252 /* I won't use option */
-# define WILL 251 /* I will use option */
-# define SB 250 /* interpret as subnegotiation */
-# define SE 240 /* end sub negotiation */
-# define NOP 241 /* No Operation */
-# define TELOPT_ECHO 1 /* echo */
-# define TELOPT_SGA 3 /* suppress go ahead */
-# define TELOPT_TTYPE 24 /* terminal type */
-# define TELOPT_NAWS 31 /* window size */
-
#define BUFSIZE 4*1024
struct term_session {
int new_fd, pty_fd;
@@ -132,7 +120,7 @@
char buf[sizeof(struct sockaddr_storage)];
memset(buf, 0, sizeof(buf));
- if (toys.optflags & FLAG_b) {
+ if (FLAG(b)) {
get_sockaddr(TT.host_addr, buf);
af = ((struct sockaddr *)buf)->sa_family;
} else {
@@ -140,8 +128,7 @@
((struct sockaddr_in*)buf)->sin_family = af;
}
s = xsocket(af, SOCK_STREAM, 0);
- if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (char *)&yes, sizeof(yes)) == -1)
- perror_exit("setsockopt");
+ xsetsockopt(s, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes));
xbind(s, (struct sockaddr *)buf, ((af == AF_INET)?
(sizeof(struct sockaddr_in)):(sizeof(struct sockaddr_in6))));
@@ -187,9 +174,9 @@
setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &i, sizeof(i));
flags = fcntl(sockfd, F_GETFL);
fcntl(sockfd, F_SETFL, flags | O_NONBLOCK);
- if (toys.optflags & FLAG_i) fcntl((sockfd + 1), F_SETFL, flags | O_NONBLOCK);
+ if (FLAG(i)) fcntl((sockfd + 1), F_SETFL, flags | O_NONBLOCK);
- writeall((toys.optflags & FLAG_i)?1:sockfd, intial_iacs, sizeof(intial_iacs));
+ writeall(FLAG(i)?1:sockfd, intial_iacs, sizeof(intial_iacs));
if ((TT.fork_pid = forkpty(&fd, tty_name, NULL, NULL)) > 0) {
flags = fcntl(fd, F_GETFL);
fcntl(fd, F_SETFL, flags | O_NONBLOCK);
@@ -300,21 +287,19 @@
void telnetd_main(void)
{
- errno = 0;
fd_set rd, wr;
struct term_session *tm = NULL;
struct timeval tv, *tv_ptr = NULL;
int pty_fd, new_fd, c = 0, w, master_fd = 0;
- int inetd_m = toys.optflags & FLAG_i;
- if (!(toys.optflags & FLAG_l)) TT.login_path = "/bin/login";
- if (!(toys.optflags & FLAG_f)) TT.issue_path = "/etc/issue.net";
- if (toys.optflags & FLAG_w) toys.optflags |= FLAG_F;
- if (!inetd_m) {
+ if (!FLAG(l)) TT.login_path = "/bin/login";
+ if (!FLAG(f)) TT.issue_path = "/etc/issue.net";
+ if (FLAG(w)) toys.optflags |= FLAG_F;
+ if (!FLAG(i)) {
master_fd = listen_socket();
fcntl(master_fd, F_SETFD, FD_CLOEXEC);
if (master_fd > TT.gmax_fd) TT.gmax_fd = master_fd;
- if (!(toys.optflags & FLAG_F)) daemon(0, 0);
+ if (!FLAG(F)) daemon(0, 0);
} else {
pty_fd = new_session(master_fd); //master_fd = 0
if (pty_fd > TT.gmax_fd) TT.gmax_fd = pty_fd;
@@ -328,7 +313,7 @@
} else session_list = tm;
}
- if ((toys.optflags & FLAG_w) && !session_list) {
+ if (FLAG(w) && !session_list) {
tv.tv_sec = TT.w_sec;
tv.tv_usec = 0;
tv_ptr = &tv;
@@ -338,7 +323,7 @@
for (;;) {
FD_ZERO(&rd);
FD_ZERO(&wr);
- if (!inetd_m) FD_SET(master_fd, &rd);
+ if (!FLAG(i)) FD_SET(master_fd, &rd);
tm = session_list;
while (tm) {
@@ -354,10 +339,10 @@
int r = select(TT.gmax_fd + 1, &rd, &wr, NULL, tv_ptr);
- if (!r) return; //timeout
+ if (!r) error_exit("select timed out");
if (r < -1) continue;
- if (!inetd_m && FD_ISSET(master_fd, &rd)) { //accept new connection
+ if (!FLAG(i) && FD_ISSET(master_fd, &rd)) { //accept new connection
new_fd = accept(master_fd, NULL, NULL);
if (new_fd < 0) continue;
tv_ptr = NULL;
@@ -382,7 +367,7 @@
if ((c = read(tm->pty_fd, tm->buff1 + tm->buff1_avail,
BUFSIZE-tm->buff1_avail)) <= 0) break;
tm->buff1_avail += c;
- if ((w = dup_iacs(tm->buff1 + tm->buff1_written, tm->new_fd + inetd_m,
+ if ((w = dup_iacs(tm->buff1 + tm->buff1_written, tm->new_fd + FLAG(i),
tm->buff1_avail - tm->buff1_written)) < 0) break;
tm->buff1_written += w;
}
@@ -401,7 +386,7 @@
tm->buff2_written += w;
}
if (FD_ISSET(tm->new_fd, &wr)) {
- if ((w = dup_iacs(tm->buff1 + tm->buff1_written, tm->new_fd + inetd_m,
+ if ((w = dup_iacs(tm->buff1 + tm->buff1_written, tm->new_fd + FLAG(i),
tm->buff1_avail - tm->buff1_written)) < 0) break;
tm->buff1_written += w;
}
@@ -421,17 +406,16 @@
// funny little dance to avoid race conditions.
toys.signal = 0;
pid = waitpid(-1, &status, WNOHANG);
- if (pid < 0) break;
+ if (pid <= 0) break;
toys.signal++;
-
for (tm = session_list; tm; tm = tm->next) {
if (tm->child_pid == pid) break;
prev = tm;
}
- if (!tm) return; // reparented child we don't care about
+ if (!tm) error_exit("unexpected reparenting of %d", pid);
- if (toys.optflags & FLAG_i) exit(EXIT_SUCCESS);
+ if (FLAG(i)) exit(EXIT_SUCCESS);
if (!prev) session_list = session_list->next;
else prev->next = tm->next;
utmp_entry();
