[package] uhttpd: fix a signal related race condition exposed by LuCI on fast machines

[openwrt.git] / package / uhttpd / src / uhttpd.c

diff --git a/package/uhttpd/src/uhttpd.c b/package/uhttpd/src/uhttpd.c
index a7db794..c6a8b6c 100644 (file)
--- a/package/uhttpd/src/uhttpd.c
+++ b/package/uhttpd/src/uhttpd.c
@@ -42,6 +42,11 @@ static void uh_sigterm(int sig)
        run = 0;
 }
 
+static void uh_sigchld(int sig)
+{
+       while( waitpid(-1, NULL, WNOHANG) > 0 ) { }
+}
+
 static void uh_config_parse(const char *path)
 {
        FILE *c;
@@ -155,6 +160,7 @@ static int uh_socket_bind(
 
                /* add socket to server fd set */
                FD_SET(sock, serv_fds);
+               fd_cloexec(sock);
                *max_fd = max(*max_fd, sock);
 
                bound++;
@@ -404,6 +410,9 @@ int main (int argc, char **argv)
        struct sigaction sa;
        struct config conf;
 
+       /* signal mask */
+       sigset_t ss;
+
        /* maximum file descriptor number */
        int new_fd, cur_fd, max_fd = 0;
 
@@ -413,7 +422,7 @@ int main (int argc, char **argv)
        int nofork = 0;
 
        /* args */
-       char opt;
+       int opt;
        char bind[128];
        char *port = NULL;
 
@@ -426,18 +435,25 @@ int main (int argc, char **argv)
        FD_ZERO(&serv_fds);
        FD_ZERO(&read_fds);
 
-       /* handle SIGPIPE, SIGCHILD */
+       /* handle SIGPIPE, SIGINT, SIGTERM, SIGCHLD */
        sa.sa_flags = 0;
        sigemptyset(&sa.sa_mask);
 
        sa.sa_handler = SIG_IGN;
        sigaction(SIGPIPE, &sa, NULL);
+
+       sa.sa_handler = uh_sigchld;
        sigaction(SIGCHLD, &sa, NULL);
 
        sa.sa_handler = uh_sigterm;
        sigaction(SIGINT,  &sa, NULL);
        sigaction(SIGTERM, &sa, NULL);
 
+       /* defer SIGCHLD */
+       sigemptyset(&ss);
+       sigaddset(&ss, SIGCHLD);
+       sigprocmask(SIG_BLOCK, &ss, NULL);
+
        /* prepare addrinfo hints */
        memset(&hints, 0, sizeof(hints));
        hints.ai_family   = AF_UNSPEC;
@@ -485,7 +501,7 @@ int main (int argc, char **argv)
        }
 #endif
 
-       while( (opt = getopt(argc, argv, "fC:K:p:s:h:c:l:L:d:r:m:x:")) > 0 )
+       while( (opt = getopt(argc, argv, "fC:K:p:s:h:c:l:L:d:r:m:x:t:")) > 0 )
        {
                switch(opt)
                {
@@ -593,6 +609,13 @@ int main (int argc, char **argv)
                                break;
 #endif
 
+#if defined(HAVE_CGI) || defined(HAVE_LUA)
+                       /* script timeout */
+                       case 't':
+                               conf.script_timeout = atoi(optarg);
+                               break;
+#endif
+
                        /* no fork */
                        case 'f':
                                nofork = 1;
@@ -644,6 +667,9 @@ int main (int argc, char **argv)
 #endif
 #ifdef HAVE_CGI
                                        "       -x string       URL prefix for CGI handler, default is '/cgi-bin'\n"
+#endif
+#if defined(HAVE_CGI) || defined(HAVE_LUA)
+                                       "       -t seconds      CGI and Lua script timeout in seconds, default is 60\n"
 #endif
                                        "       -d string       URL decode given string\n"
                                        "       -r string       Specify basic auth realm\n"
@@ -684,6 +710,12 @@ int main (int argc, char **argv)
        /* config file */
        uh_config_parse(conf.file);
 
+#if defined(HAVE_CGI) || defined(HAVE_LUA)
+       /* default script timeout */
+       if( conf.script_timeout <= 0 )
+               conf.script_timeout = 60;
+#endif
+
 #ifdef HAVE_CGI
        /* default cgi prefix */
        if( ! conf.cgi_prefix )
@@ -794,6 +826,7 @@ int main (int argc, char **argv)
 
                                                        /* add client socket to global fdset */
                                                        FD_SET(new_fd, &used_fds);
+                                                       fd_cloexec(new_fd);
                                                        max_fd = max(max_fd, new_fd);
                                                }