commit: c119fe8e393540224c803ab5036ddb80b800716c Author: Mike Frysinger <vapier <AT> gentoo <DOT> org> AuthorDate: Sat Feb 23 04:52:47 2013 +0000 Commit: Mike Frysinger <vapier <AT> gentoo <DOT> org> CommitDate: Sat Feb 23 04:52:47 2013 +0000 URL: https://gitweb.gentoo.org/proj/sandbox.git/commit/?id=c119fe8e
sandbox: pass child signals back up to the parent We were incorrectly passing signal information back up to the parent. See the URL for more information. URL: http://www.cons.org/cracauer/sigint.html Signed-off-by: Mike Frysinger <vapier <AT> gentoo.org> src/sandbox.c | 72 +++++++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 48 insertions(+), 24 deletions(-) diff --git a/src/sandbox.c b/src/sandbox.c index 3783bca..c2a1d25 100644 --- a/src/sandbox.c +++ b/src/sandbox.c @@ -131,7 +131,7 @@ static void print_sandbox_log(char *sandbox_log) static void stop(int signum) { if (0 == stop_called) { - stop_called = 1; + stop_called = signum; sb_warn("caught signal %d in pid %d", signum, getpid()); } else sb_warn("signal already caught and busy still cleaning up!"); @@ -140,7 +140,7 @@ static void stop(int signum) static void usr1_handler(int signum, siginfo_t *siginfo, void *ucontext) { if (0 == stop_called) { - stop_called = 1; + stop_called = signum; sb_warn("caught signal %d in pid %d", signum, getpid()); /* FIXME: This is really bad form, as we should kill the whole process @@ -183,12 +183,11 @@ static int spawn_shell(char *argv_bash[], char **env, int debug) sb_pwarn("failed to waitpid for child"); return 1; } else if (status != 0) { - if (WIFSIGNALED(status)) { + if (WIFSIGNALED(status)) psignal(WTERMSIG(status), "Sandboxed process killed by signal"); - return 128 + WTERMSIG(status); - } else if (debug) + else if (debug) sb_warn("process returned with failed exit status %d!", WEXITSTATUS(status)); - return WEXITSTATUS(status) ? : 1; + return status; } return 0; @@ -196,8 +195,6 @@ static int spawn_shell(char *argv_bash[], char **env, int debug) int main(int argc, char **argv) { - struct sigaction act_new; - int sandbox_log_presence = 0; struct sandbox_info_t sandbox_info; @@ -308,26 +305,39 @@ int main(int argc, char **argv) } } - /* set up the required signal handlers ... but allow SIGHUP to be - * ignored in case people are running `nohup ...` #217898 - */ - if (signal(SIGHUP, &stop) == SIG_IGN) - signal(SIGHUP, SIG_IGN); -#define wsignal(sig, act) \ + /* Set up the required signal handlers */ + int sigs[] = { SIGHUP, SIGINT, SIGQUIT, SIGTERM, SIGUSR1, }; + struct sigaction act_new, act_old[ARRAY_SIZE(sigs)]; + size_t si = 0; + +#define wsigaction() \ do { \ - sighandler_t _old = signal(sig, act); \ - if (_old == SIG_ERR) \ - sb_pwarn("unable to bind signal %s", #sig); \ - else if (_old != SIG_DFL && _old != SIG_IGN) \ - sb_warn("signal %s already had a handler ...", #sig); \ + if (sigaction(sigs[si], &act_new, &act_old[si])) \ + sb_pwarn("unable to bind signal %i", sigs[si]); \ + else if (act_old[si].sa_handler != SIG_DFL && \ + act_old[si].sa_handler != SIG_IGN) \ + sb_warn("signal %i already had a handler ...", sigs[si]); \ + ++si; \ } while (0) - wsignal(SIGINT, &stop); - wsignal(SIGQUIT, &stop); - wsignal(SIGTERM, &stop); + + sigemptyset(&act_new.sa_mask); + act_new.sa_sigaction = NULL; + act_new.sa_handler = stop; + act_new.sa_flags = SA_RESTART; + wsigaction(); + wsigaction(); + wsigaction(); + wsigaction(); + + sigemptyset(&act_new.sa_mask); + act_new.sa_handler = NULL; act_new.sa_sigaction = usr1_handler; - sigemptyset (&act_new.sa_mask); act_new.sa_flags = SA_SIGINFO | SA_RESTART; - sigaction (SIGUSR1, &act_new, NULL); + wsigaction(); + + /* Allow SIGHUP to be ignored in case people are running `nohup ...` #217898 */ + if (act_old[0].sa_handler == SIG_IGN) + sigaction(SIGHUP, &act_old[0], NULL); /* STARTING PROTECTED ENVIRONMENT */ dputs("The protected environment has been started."); @@ -353,6 +363,20 @@ int main(int argc, char **argv) } else dputs(sandbox_footer); + /* Do the right thing and pass the signal back up. See: + * http://www.cons.org/cracauer/sigint.html + */ + if (stop_called != SIGUSR1 && WIFSIGNALED(shell_exit)) { + int signum = WTERMSIG(shell_exit); + for (si = 0; si < ARRAY_SIZE(sigs); ++si) + sigaction(sigs[si], &act_old[si], NULL); + kill(getpid(), signum); + return 128 + signum; + } else if (WIFEXITED(shell_exit)) + shell_exit = WEXITSTATUS(shell_exit); + else + shell_exit = 1; /* ??? */ + if (!is_env_on(ENV_SANDBOX_TESTING)) if (sandbox_log_presence && shell_exit == 0) shell_exit = 1;
