Loading tests/server/sockfilt.c +172 −24 Original line number Diff line number Diff line Loading @@ -46,6 +46,40 @@ * * (Source originally based on sws.c) */ /* * Signal handling notes for sockfilt * ---------------------------------- * * This program is a single-threaded process. * * This program is intended to be highly portable and as such it must be kept as * simple as possible, due to this the only signal handling mechanisms used will * be those of ANSI C, and used only in the most basic form which is good enough * for the purpose of this program. * * For the above reason and the specific needs of this program signals SIGHUP, * SIGPIPE and SIGALRM will be simply ignored on systems where this can be done. * If possible, signals SIGINT and SIGTERM will be handled by this program as an * indication to cleanup and finish execution as soon as possible. This will be * achieved with a single signal handler 'exit_signal_handler' for both signals. * * The 'exit_signal_handler' upon the first SIGINT or SIGTERM received signal * will just set to one the global var 'got_exit_signal' storing in global var * 'exit_signal' the signal that triggered this change. * * Nothing fancy that could introduce problems is used, the program at certain * points in its normal flow checks if var 'got_exit_signal' is set and in case * this is true it just makes its way out of loops and functions in structured * and well behaved manner to achieve proper program cleanup and termination. * * Even with the above mechanism implemented it is worthwile to note that other * signals might still be received, or that there might be systems on which it * is not possible to trap and ignore some of the above signals. This implies * that for increased portability and reliability the program must be coded as * if no signal was being ignored or handled at all. Enjoy it! */ #include "setup.h" /* portability help from the lib directory */ #ifdef HAVE_SIGNAL_H Loading Loading @@ -85,10 +119,6 @@ #define DEFAULT_LOGFILE "log/sockfilt.log" #endif #ifdef SIGPIPE static volatile int sigpipe; /* Why? It's not used */ #endif const char *serverlogfile = (char *)DEFAULT_LOGFILE; bool verbose = FALSE; Loading @@ -103,6 +133,103 @@ enum sockmode { ACTIVE_DISCONNECT /* as a client, disconnected from server */ }; /* do-nothing macro replacement for systems which lack siginterrupt() */ #ifndef HAVE_SIGINTERRUPT #define siginterrupt(x,y) do {} while(0) #endif /* vars used to keep around previous signal handlers */ typedef RETSIGTYPE (*SIGHANDLER_T)(int); static SIGHANDLER_T old_sighup_handler = SIG_ERR; static SIGHANDLER_T old_sigpipe_handler = SIG_ERR; static SIGHANDLER_T old_sigalrm_handler = SIG_ERR; static SIGHANDLER_T old_sigint_handler = SIG_ERR; static SIGHANDLER_T old_sigterm_handler = SIG_ERR; /* var which if set indicates that the program should finish execution */ SIG_ATOMIC_T got_exit_signal = 0; /* if next is set indicates the first signal handled in exit_signal_handler */ static volatile int exit_signal = 0; /* signal handler that will be triggered to indicate that the program should finish its execution in a controlled manner as soon as possible. The first time this is called it will set got_exit_signal to one and store in exit_signal the signal that triggered its execution. */ static RETSIGTYPE exit_signal_handler(int signum) { int old_errno = ERRNO; if(got_exit_signal == 0) { got_exit_signal = 1; exit_signal = signum; } (void)signal(signum, exit_signal_handler); SET_ERRNO(old_errno); } static void install_signal_handlers(void) { #ifdef SIGHUP /* ignore SIGHUP signal */ if((old_sighup_handler = signal(SIGHUP, SIG_IGN)) == SIG_ERR) logmsg("cannot install SIGHUP handler: 5s", strerror(ERRNO)); #endif #ifdef SIGPIPE /* ignore SIGPIPE signal */ if((old_sigpipe_handler = signal(SIGPIPE, SIG_IGN)) == SIG_ERR) logmsg("cannot install SIGPIPE handler: 5s", strerror(ERRNO)); #endif #ifdef SIGALRM /* ignore SIGALRM signal */ if((old_sigalrm_handler = signal(SIGALRM, SIG_IGN)) == SIG_ERR) logmsg("cannot install SIGALRM handler: 5s", strerror(ERRNO)); #endif #ifdef SIGINT /* handle SIGINT signal with our exit_signal_handler */ if((old_sigint_handler = signal(SIGINT, exit_signal_handler)) == SIG_ERR) logmsg("cannot install SIGINT handler: 5s", strerror(ERRNO)); else siginterrupt(SIGINT, 1); #endif #ifdef SIGTERM /* handle SIGTERM signal with our exit_signal_handler */ if((old_sigterm_handler = signal(SIGTERM, exit_signal_handler)) == SIG_ERR) logmsg("cannot install SIGTERM handler: 5s", strerror(ERRNO)); else siginterrupt(SIGTERM, 1); #endif } static void restore_signal_handlers(void) { #ifdef SIGHUP if(SIG_ERR != old_sighup_handler) (void)signal(SIGHUP, old_sighup_handler); #endif #ifdef SIGPIPE if(SIG_ERR != old_sigpipe_handler) (void)signal(SIGPIPE, old_sigpipe_handler); #endif #ifdef SIGALRM if(SIG_ERR != old_sigalrm_handler) (void)signal(SIGALRM, old_sigalrm_handler); #endif #ifdef SIGINT if(SIG_ERR != old_sigint_handler) (void)signal(SIGINT, old_sigint_handler); #endif #ifdef SIGTERM if(SIG_ERR != old_sigterm_handler) (void)signal(SIGTERM, old_sigterm_handler); #endif } /* * fullread is a wrapper around the read() function. This will repeat the call * to read() until it actually has read the complete number of bytes indicated Loading @@ -119,6 +246,11 @@ static ssize_t fullread(int filedes, void *buffer, size_t nbytes) do { rc = read(filedes, (unsigned char *)buffer + nread, nbytes - nread); if(got_exit_signal) { logmsg("signalled to die"); return -1; } if(rc < 0) { error = ERRNO; if((error == EINTR) || (error == EAGAIN)) Loading Loading @@ -158,6 +290,11 @@ static ssize_t fullwrite(int filedes, const void *buffer, size_t nbytes) do { wc = write(filedes, (unsigned char *)buffer + nwrite, nbytes - nwrite); if(got_exit_signal) { logmsg("signalled to die"); return -1; } if(wc < 0) { error = ERRNO; if((error == EINTR) || (error == EAGAIN)) Loading Loading @@ -252,14 +389,6 @@ static void lograw(unsigned char *buffer, ssize_t len) logmsg("'%s'", data); } #ifdef SIGPIPE static void sigpipe_handler(int sig) { (void)sig; /* prevent warning */ sigpipe = 1; } #endif /* sockfdp is a pointer to an established stream or CURL_SOCKET_BAD Loading Loading @@ -287,6 +416,11 @@ static bool juggle(curl_socket_t *sockfdp, unsigned char buffer[17010]; char data[16]; if(got_exit_signal) { logmsg("signalled to die, exiting..."); return FALSE; } #ifdef HAVE_GETPPID /* As a last resort, quit if sockfilt process becomes orphan. Just in case parent ftpserver process has died without killing its sockfilt children */ Loading Loading @@ -359,6 +493,11 @@ static bool juggle(curl_socket_t *sockfdp, rc = select((int)maxfd + 1, &fds_read, &fds_write, &fds_err, &timeout); if(got_exit_signal) { logmsg("signalled to die, exiting..."); return FALSE; } } while((rc == -1) && ((error = SOCKERRNO) == EINTR)); if(rc < 0) { Loading Loading @@ -549,6 +688,11 @@ static curl_socket_t sockdaemon(curl_socket_t sock, sclose(sock); return CURL_SOCKET_BAD; } if(got_exit_signal) { logmsg("signalled to die, exiting..."); sclose(sock); return CURL_SOCKET_BAD; } totdelay += delay; delay *= 2; /* double the sleep for next attempt */ } Loading Loading @@ -712,18 +856,10 @@ int main(int argc, char *argv[]) #ifdef WIN32 win32_init(); atexit(win32_cleanup); #else #ifdef SIGPIPE #ifdef HAVE_SIGNAL signal(SIGPIPE, sigpipe_handler); #endif #ifdef HAVE_SIGINTERRUPT siginterrupt(SIGPIPE, 1); #endif #endif #endif install_signal_handlers(); #ifdef ENABLE_IPV6 if(!use_ipv6) #endif Loading Loading @@ -810,6 +946,18 @@ sockfilt_cleanup: if(wrotepidfile) unlink(pidname); restore_signal_handlers(); if(got_exit_signal) { logmsg("============> sockfilt exits with signal (%d)", exit_signal); /* * To properly set the return status of the process we * must raise the same signal SIGINT or SIGTERM that we * caught and let the old handler take care of it. */ raise(exit_signal); } logmsg("============> sockfilt quits"); return 0; } Loading Loading
tests/server/sockfilt.c +172 −24 Original line number Diff line number Diff line Loading @@ -46,6 +46,40 @@ * * (Source originally based on sws.c) */ /* * Signal handling notes for sockfilt * ---------------------------------- * * This program is a single-threaded process. * * This program is intended to be highly portable and as such it must be kept as * simple as possible, due to this the only signal handling mechanisms used will * be those of ANSI C, and used only in the most basic form which is good enough * for the purpose of this program. * * For the above reason and the specific needs of this program signals SIGHUP, * SIGPIPE and SIGALRM will be simply ignored on systems where this can be done. * If possible, signals SIGINT and SIGTERM will be handled by this program as an * indication to cleanup and finish execution as soon as possible. This will be * achieved with a single signal handler 'exit_signal_handler' for both signals. * * The 'exit_signal_handler' upon the first SIGINT or SIGTERM received signal * will just set to one the global var 'got_exit_signal' storing in global var * 'exit_signal' the signal that triggered this change. * * Nothing fancy that could introduce problems is used, the program at certain * points in its normal flow checks if var 'got_exit_signal' is set and in case * this is true it just makes its way out of loops and functions in structured * and well behaved manner to achieve proper program cleanup and termination. * * Even with the above mechanism implemented it is worthwile to note that other * signals might still be received, or that there might be systems on which it * is not possible to trap and ignore some of the above signals. This implies * that for increased portability and reliability the program must be coded as * if no signal was being ignored or handled at all. Enjoy it! */ #include "setup.h" /* portability help from the lib directory */ #ifdef HAVE_SIGNAL_H Loading Loading @@ -85,10 +119,6 @@ #define DEFAULT_LOGFILE "log/sockfilt.log" #endif #ifdef SIGPIPE static volatile int sigpipe; /* Why? It's not used */ #endif const char *serverlogfile = (char *)DEFAULT_LOGFILE; bool verbose = FALSE; Loading @@ -103,6 +133,103 @@ enum sockmode { ACTIVE_DISCONNECT /* as a client, disconnected from server */ }; /* do-nothing macro replacement for systems which lack siginterrupt() */ #ifndef HAVE_SIGINTERRUPT #define siginterrupt(x,y) do {} while(0) #endif /* vars used to keep around previous signal handlers */ typedef RETSIGTYPE (*SIGHANDLER_T)(int); static SIGHANDLER_T old_sighup_handler = SIG_ERR; static SIGHANDLER_T old_sigpipe_handler = SIG_ERR; static SIGHANDLER_T old_sigalrm_handler = SIG_ERR; static SIGHANDLER_T old_sigint_handler = SIG_ERR; static SIGHANDLER_T old_sigterm_handler = SIG_ERR; /* var which if set indicates that the program should finish execution */ SIG_ATOMIC_T got_exit_signal = 0; /* if next is set indicates the first signal handled in exit_signal_handler */ static volatile int exit_signal = 0; /* signal handler that will be triggered to indicate that the program should finish its execution in a controlled manner as soon as possible. The first time this is called it will set got_exit_signal to one and store in exit_signal the signal that triggered its execution. */ static RETSIGTYPE exit_signal_handler(int signum) { int old_errno = ERRNO; if(got_exit_signal == 0) { got_exit_signal = 1; exit_signal = signum; } (void)signal(signum, exit_signal_handler); SET_ERRNO(old_errno); } static void install_signal_handlers(void) { #ifdef SIGHUP /* ignore SIGHUP signal */ if((old_sighup_handler = signal(SIGHUP, SIG_IGN)) == SIG_ERR) logmsg("cannot install SIGHUP handler: 5s", strerror(ERRNO)); #endif #ifdef SIGPIPE /* ignore SIGPIPE signal */ if((old_sigpipe_handler = signal(SIGPIPE, SIG_IGN)) == SIG_ERR) logmsg("cannot install SIGPIPE handler: 5s", strerror(ERRNO)); #endif #ifdef SIGALRM /* ignore SIGALRM signal */ if((old_sigalrm_handler = signal(SIGALRM, SIG_IGN)) == SIG_ERR) logmsg("cannot install SIGALRM handler: 5s", strerror(ERRNO)); #endif #ifdef SIGINT /* handle SIGINT signal with our exit_signal_handler */ if((old_sigint_handler = signal(SIGINT, exit_signal_handler)) == SIG_ERR) logmsg("cannot install SIGINT handler: 5s", strerror(ERRNO)); else siginterrupt(SIGINT, 1); #endif #ifdef SIGTERM /* handle SIGTERM signal with our exit_signal_handler */ if((old_sigterm_handler = signal(SIGTERM, exit_signal_handler)) == SIG_ERR) logmsg("cannot install SIGTERM handler: 5s", strerror(ERRNO)); else siginterrupt(SIGTERM, 1); #endif } static void restore_signal_handlers(void) { #ifdef SIGHUP if(SIG_ERR != old_sighup_handler) (void)signal(SIGHUP, old_sighup_handler); #endif #ifdef SIGPIPE if(SIG_ERR != old_sigpipe_handler) (void)signal(SIGPIPE, old_sigpipe_handler); #endif #ifdef SIGALRM if(SIG_ERR != old_sigalrm_handler) (void)signal(SIGALRM, old_sigalrm_handler); #endif #ifdef SIGINT if(SIG_ERR != old_sigint_handler) (void)signal(SIGINT, old_sigint_handler); #endif #ifdef SIGTERM if(SIG_ERR != old_sigterm_handler) (void)signal(SIGTERM, old_sigterm_handler); #endif } /* * fullread is a wrapper around the read() function. This will repeat the call * to read() until it actually has read the complete number of bytes indicated Loading @@ -119,6 +246,11 @@ static ssize_t fullread(int filedes, void *buffer, size_t nbytes) do { rc = read(filedes, (unsigned char *)buffer + nread, nbytes - nread); if(got_exit_signal) { logmsg("signalled to die"); return -1; } if(rc < 0) { error = ERRNO; if((error == EINTR) || (error == EAGAIN)) Loading Loading @@ -158,6 +290,11 @@ static ssize_t fullwrite(int filedes, const void *buffer, size_t nbytes) do { wc = write(filedes, (unsigned char *)buffer + nwrite, nbytes - nwrite); if(got_exit_signal) { logmsg("signalled to die"); return -1; } if(wc < 0) { error = ERRNO; if((error == EINTR) || (error == EAGAIN)) Loading Loading @@ -252,14 +389,6 @@ static void lograw(unsigned char *buffer, ssize_t len) logmsg("'%s'", data); } #ifdef SIGPIPE static void sigpipe_handler(int sig) { (void)sig; /* prevent warning */ sigpipe = 1; } #endif /* sockfdp is a pointer to an established stream or CURL_SOCKET_BAD Loading Loading @@ -287,6 +416,11 @@ static bool juggle(curl_socket_t *sockfdp, unsigned char buffer[17010]; char data[16]; if(got_exit_signal) { logmsg("signalled to die, exiting..."); return FALSE; } #ifdef HAVE_GETPPID /* As a last resort, quit if sockfilt process becomes orphan. Just in case parent ftpserver process has died without killing its sockfilt children */ Loading Loading @@ -359,6 +493,11 @@ static bool juggle(curl_socket_t *sockfdp, rc = select((int)maxfd + 1, &fds_read, &fds_write, &fds_err, &timeout); if(got_exit_signal) { logmsg("signalled to die, exiting..."); return FALSE; } } while((rc == -1) && ((error = SOCKERRNO) == EINTR)); if(rc < 0) { Loading Loading @@ -549,6 +688,11 @@ static curl_socket_t sockdaemon(curl_socket_t sock, sclose(sock); return CURL_SOCKET_BAD; } if(got_exit_signal) { logmsg("signalled to die, exiting..."); sclose(sock); return CURL_SOCKET_BAD; } totdelay += delay; delay *= 2; /* double the sleep for next attempt */ } Loading Loading @@ -712,18 +856,10 @@ int main(int argc, char *argv[]) #ifdef WIN32 win32_init(); atexit(win32_cleanup); #else #ifdef SIGPIPE #ifdef HAVE_SIGNAL signal(SIGPIPE, sigpipe_handler); #endif #ifdef HAVE_SIGINTERRUPT siginterrupt(SIGPIPE, 1); #endif #endif #endif install_signal_handlers(); #ifdef ENABLE_IPV6 if(!use_ipv6) #endif Loading Loading @@ -810,6 +946,18 @@ sockfilt_cleanup: if(wrotepidfile) unlink(pidname); restore_signal_handlers(); if(got_exit_signal) { logmsg("============> sockfilt exits with signal (%d)", exit_signal); /* * To properly set the return status of the process we * must raise the same signal SIGINT or SIGTERM that we * caught and let the old handler take care of it. */ raise(exit_signal); } logmsg("============> sockfilt quits"); return 0; } Loading
