https://github.com/gnosek/fcgiwrap/pull/60 From 93ce8e8489bda4a7ebe5161020c83a68f744481f Mon Sep 17 00:00:00 2001 From: flu0r1ne Date: Sat, 9 Sep 2023 22:56:05 -0500 Subject: [PATCH 1/4] Fix implicit fallthrough false positive, noreturn With warnings and pedantic mode enabled, `gcc (GCC) 13.2.1` returns an implicit fall through warning. This can be fixed by annotating the error function with NORETURN. --- fcgiwrap.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/fcgiwrap.c b/fcgiwrap.c index b44d8aa..8310284 100644 --- a/fcgiwrap.c +++ b/fcgiwrap.c @@ -56,6 +56,12 @@ #define UNIX_PATH_MAX 108 #endif +#if defined(__GNUC__) || defined(__clang__) +# define NORETURN __attribute__((__noreturn__)) +#else +# define NORETURN +#endif + extern char **environ; static char * const * inherited_environ; static const char **allowed_programs; @@ -500,7 +506,7 @@ static bool is_allowed_program(const char *program) { return false; } -static void cgi_error(const char *message, const char *reason, const char *filename) +static void NORETURN cgi_error(const char *message, const char *reason, const char *filename) { printf("Status: %s\r\nContent-Type: text/plain\r\n\r\n%s\r\n", message, message); From 8b8aae2ac99bc91a72a32ca2040302f785e10e2b Mon Sep 17 00:00:00 2001 From: flu0r1ne Date: Sun, 10 Sep 2023 03:50:27 -0500 Subject: [PATCH 2/4] close() always results in a duplicate call Remove close as it always results in a duplicated call, simplify logic --- fcgiwrap.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-) diff --git a/fcgiwrap.c b/fcgiwrap.c index 8310284..cfb7797 100644 --- a/fcgiwrap.c +++ b/fcgiwrap.c @@ -62,6 +62,8 @@ # define NORETURN #endif +#define FCGI_FD 0 + extern char **environ; static char * const * inherited_environ; static const char **allowed_programs; @@ -706,8 +708,8 @@ static int listen_on_fd(int fd) { perror("Failed to enable SO_REUSEADDR"); return -1; } - if (dup2(fd, 0) < 0) { - perror("Failed to move socket to fd 0"); + if (dup2(fd, FCGI_FD) < 0) { + fprintf(stderr, "Failed to move socket to fd %d", FCGI_FD); return -1; } if (close(fd) < 0) { @@ -809,7 +811,7 @@ int main(int argc, char **argv) { int nchildren = 1; char *socket_url = NULL; - int fd = 0; + int fd = FCGI_FD; int c; while ((c = getopt(argc, argv, "c:hfs:p:")) != -1) { @@ -860,6 +862,10 @@ int main(int argc, char **argv) #ifdef HAVE_SYSTEMD if (sd_listen_fds(true) > 0) { + if(socket_url) { + perror("warning: a systemd socket has been provding, ignoring '-s'\n"); + } + /* systemd woke us up. we should never see more than one FD passed to us. */ if (listen_on_fd(SD_LISTEN_FDS_START) < 0) { return 1; @@ -876,16 +882,15 @@ int main(int argc, char **argv) prefork(nchildren); fcgiwrap_main(); - if (fd) { - const char *p = socket_url; - close(fd); + close(FCGI_FD); - if (socket_url) { - if (!strncmp(p, "unix:", sizeof("unix:") - 1)) { - p += sizeof("unix:") - 1; - unlink(p); - } + if (fd && socket_url) { // fd > 0 indicates a socket was setup by us + const char *p = socket_url; + if (!strncmp(p, "unix:", sizeof("unix:") - 1)) { + p += sizeof("unix:") - 1; + unlink(p); } } + return 0; } From b4f2469369960fb914c1d1eb4942feebf648835a Mon Sep 17 00:00:00 2001 From: flu0r1ne Date: Sun, 10 Sep 2023 04:14:17 -0500 Subject: [PATCH 3/4] Add better error handling for socket setup --- fcgiwrap.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/fcgiwrap.c b/fcgiwrap.c index cfb7797..5b8af47 100644 --- a/fcgiwrap.c +++ b/fcgiwrap.c @@ -793,18 +793,30 @@ static int setup_socket(char *url) { fd = socket(sa.sa.sa_family, SOCK_STREAM, 0); if (fd < 0) { perror("Failed to create socket"); - return -1; + goto cleanup_socket; } if (bind(fd, &sa.sa, sockaddr_size) < 0) { perror("Failed to bind"); - return -1; + goto cleanup_fd; } if (listen_on_fd(fd) < 0) { - return -1; + goto cleanup_fd; } return fd; + +cleanup_fd: + + close(fd); + +cleanup_socket: + + if(sa.sa.sa_family == AF_UNIX) { + unlink(sa.sa_un.sun_path); + } + + return -1; } int main(int argc, char **argv) From 2870d2729a3930988f0041e2d78fec672e69afac Mon Sep 17 00:00:00 2001 From: flu0r1ne Date: Sun, 10 Sep 2023 04:36:16 -0500 Subject: [PATCH 4/4] Kill all child processes on parent SIGTERM When attached to a terminal, a SIGINT signal is sent to the parent and all children, instructing them to exit. In some environments including docker, only the parent receives the SIGTERM and is responsible for propagating it to the children. This patch kills all child processes when the parent receives a SIGTERM or a SIGINT. --- fcgiwrap.c | 38 ++++++++++++++++++++++++++++---------- 1 file changed, 28 insertions(+), 10 deletions(-) diff --git a/fcgiwrap.c b/fcgiwrap.c index 5b8af47..123d279 100644 --- a/fcgiwrap.c +++ b/fcgiwrap.c @@ -62,6 +62,12 @@ # define NORETURN #endif +#if defined(__GNUC__) +# define UNUSED __attribute__((__unused__)) +#else +# define UNUSED +#endif + #define FCGI_FD 0 extern char **environ; @@ -646,6 +652,8 @@ static void fcgiwrap_main(void) while (FCGI_Accept() >= 0 && !sigint_received) { handle_fcgi_request(); } + + close(FCGI_FD); } static volatile sig_atomic_t nrunning; @@ -665,21 +673,26 @@ static void sigchld_handler(int dummy) } } +static volatile sig_atomic_t stop_requested; + +static void stop_request_handler(int UNUSED signum) { + stop_requested = 1; +} + static void prefork(int nchildren) { int startup = 1; - if (nchildren == 1) { - return; - } - signal(SIGCHLD, sigchld_handler); + signal(SIGINT, stop_request_handler); + signal(SIGTERM, stop_request_handler); - while (1) { + while (!stop_requested) { while (nrunning < nchildren) { pid_t pid = fork(); if (pid == 0) { - return; + fcgiwrap_main(); + exit(0); } else if (pid != -1) { nrunning++; } else { @@ -695,6 +708,10 @@ static void prefork(int nchildren) startup = 0; pause(); } + + if(killpg(0, SIGTERM) != 0) { + fprintf(stderr, "killpg() encountered an error, child processes may have to be killed"); + } } static int listen_on_fd(int fd) { @@ -891,10 +908,11 @@ int main(int argc, char **argv) } } - prefork(nchildren); - fcgiwrap_main(); - - close(FCGI_FD); + if(nchildren > 1) { + prefork(nchildren); + } else { + fcgiwrap_main(); + } if (fd && socket_url) { // fd > 0 indicates a socket was setup by us const char *p = socket_url;