build-sys: split internal basic/ library from shared/

basic/      can be used by everything
            cannot use anything outside of basic/

libsystemd/ can use basic/
            cannot use shared/

shared/     can use libsystemd/

1 files changed, 268 insertions, 0 deletions

diff --git a/src/basic/signal-util.c b/src/basic/signal-util.c
new file mode 100644
index 0000000000..84cf42b285
--- /dev/null
+++ b/src/basic/signal-util.c
@@ -0,0 +1,268 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2015 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include "util.h"
+#include "signal-util.h"
+
+int reset_all_signal_handlers(void) {
+        static const struct sigaction sa = {
+                .sa_handler = SIG_DFL,
+                .sa_flags = SA_RESTART,
+        };
+        int sig, r = 0;
+
+        for (sig = 1; sig < _NSIG; sig++) {
+
+                /* These two cannot be caught... */
+                if (sig == SIGKILL || sig == SIGSTOP)
+                        continue;
+
+                /* On Linux the first two RT signals are reserved by
+                 * glibc, and sigaction() will return EINVAL for them. */
+                if ((sigaction(sig, &sa, NULL) < 0))
+                        if (errno != EINVAL && r >= 0)
+                                r = -errno;
+        }
+
+        return r;
+}
+
+int reset_signal_mask(void) {
+        sigset_t ss;
+
+        if (sigemptyset(&ss) < 0)
+                return -errno;
+
+        if (sigprocmask(SIG_SETMASK, &ss, NULL) < 0)
+                return -errno;
+
+        return 0;
+}
+
+static int sigaction_many_ap(const struct sigaction *sa, int sig, va_list ap) {
+        int r = 0;
+
+        /* negative signal ends the list. 0 signal is skipped. */
+
+        if (sig < 0)
+                return 0;
+
+        if (sig > 0) {
+                if (sigaction(sig, sa, NULL) < 0)
+                        r = -errno;
+        }
+
+        while ((sig = va_arg(ap, int)) >= 0) {
+
+                if (sig == 0)
+                        continue;
+
+                if (sigaction(sig, sa, NULL) < 0) {
+                        if (r >= 0)
+                                r = -errno;
+                }
+        }
+
+        return r;
+}
+
+int sigaction_many(const struct sigaction *sa, ...) {
+        va_list ap;
+        int r;
+
+        va_start(ap, sa);
+        r = sigaction_many_ap(sa, 0, ap);
+        va_end(ap);
+
+        return r;
+}
+
+int ignore_signals(int sig, ...) {
+
+        static const struct sigaction sa = {
+                .sa_handler = SIG_IGN,
+                .sa_flags = SA_RESTART,
+        };
+
+        va_list ap;
+        int r;
+
+        va_start(ap, sig);
+        r = sigaction_many_ap(&sa, sig, ap);
+        va_end(ap);
+
+        return r;
+}
+
+int default_signals(int sig, ...) {
+
+        static const struct sigaction sa = {
+                .sa_handler = SIG_DFL,
+                .sa_flags = SA_RESTART,
+        };
+
+        va_list ap;
+        int r;
+
+        va_start(ap, sig);
+        r = sigaction_many_ap(&sa, sig, ap);
+        va_end(ap);
+
+        return r;
+}
+
+static int sigset_add_many_ap(sigset_t *ss, va_list ap) {
+        int sig, r = 0;
+
+        assert(ss);
+
+        while ((sig = va_arg(ap, int)) >= 0) {
+
+                if (sig == 0)
+                        continue;
+
+                if (sigaddset(ss, sig) < 0) {
+                        if (r >= 0)
+                                r = -errno;
+                }
+        }
+
+        return r;
+}
+
+int sigset_add_many(sigset_t *ss, ...) {
+        va_list ap;
+        int r;
+
+        va_start(ap, ss);
+        r = sigset_add_many_ap(ss, ap);
+        va_end(ap);
+
+        return r;
+}
+
+int sigprocmask_many(int how, ...) {
+        va_list ap;
+        sigset_t ss;
+        int r;
+
+        if (sigemptyset(&ss) < 0)
+                return -errno;
+
+        va_start(ap, how);
+        r = sigset_add_many_ap(&ss, ap);
+        va_end(ap);
+
+        if (r < 0)
+                return r;
+
+        if (sigprocmask(how, &ss, NULL) < 0)
+                return -errno;
+
+        return 0;
+}
+
+static const char *const __signal_table[] = {
+        [SIGHUP] = "HUP",
+        [SIGINT] = "INT",
+        [SIGQUIT] = "QUIT",
+        [SIGILL] = "ILL",
+        [SIGTRAP] = "TRAP",
+        [SIGABRT] = "ABRT",
+        [SIGBUS] = "BUS",
+        [SIGFPE] = "FPE",
+        [SIGKILL] = "KILL",
+        [SIGUSR1] = "USR1",
+        [SIGSEGV] = "SEGV",
+        [SIGUSR2] = "USR2",
+        [SIGPIPE] = "PIPE",
+        [SIGALRM] = "ALRM",
+        [SIGTERM] = "TERM",
+#ifdef SIGSTKFLT
+        [SIGSTKFLT] = "STKFLT",  /* Linux on SPARC doesn't know SIGSTKFLT */
+#endif
+        [SIGCHLD] = "CHLD",
+        [SIGCONT] = "CONT",
+        [SIGSTOP] = "STOP",
+        [SIGTSTP] = "TSTP",
+        [SIGTTIN] = "TTIN",
+        [SIGTTOU] = "TTOU",
+        [SIGURG] = "URG",
+        [SIGXCPU] = "XCPU",
+        [SIGXFSZ] = "XFSZ",
+        [SIGVTALRM] = "VTALRM",
+        [SIGPROF] = "PROF",
+        [SIGWINCH] = "WINCH",
+        [SIGIO] = "IO",
+        [SIGPWR] = "PWR",
+        [SIGSYS] = "SYS"
+};
+
+DEFINE_PRIVATE_STRING_TABLE_LOOKUP(__signal, int);
+
+const char *signal_to_string(int signo) {
+        static thread_local char buf[sizeof("RTMIN+")-1 + DECIMAL_STR_MAX(int) + 1];
+        const char *name;
+
+        name = __signal_to_string(signo);
+        if (name)
+                return name;
+
+        if (signo >= SIGRTMIN && signo <= SIGRTMAX)
+                snprintf(buf, sizeof(buf), "RTMIN+%d", signo - SIGRTMIN);
+        else
+                snprintf(buf, sizeof(buf), "%d", signo);
+
+        return buf;
+}
+
+int signal_from_string(const char *s) {
+        int signo;
+        int offset = 0;
+        unsigned u;
+
+        signo = __signal_from_string(s);
+        if (signo > 0)
+                return signo;
+
+        if (startswith(s, "RTMIN+")) {
+                s += 6;
+                offset = SIGRTMIN;
+        }
+        if (safe_atou(s, &u) >= 0) {
+                signo = (int) u + offset;
+                if (signo > 0 && signo < _NSIG)
+                        return signo;
+        }
+        return -EINVAL;
+}
+
+int signal_from_string_try_harder(const char *s) {
+        int signo;
+        assert(s);
+
+        signo = signal_from_string(s);
+        if (signo <= 0)
+                if (startswith(s, "SIG"))
+                        return signal_from_string(s+3);
+
+        return signo;
+}