Adding upstream version 241.upstream/241upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 290 insertions, 0 deletions

diff --git a/src/basic/signal-util.c b/src/basic/signal-util.c
new file mode 100644
index 0000000..fb8a63f
--- /dev/null
+++ b/src/basic/signal-util.c
@@ -0,0 +1,290 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <stdarg.h>
+#include <stdio.h>
+
+#include "macro.h"
+#include "parse-util.h"
+#include "signal-util.h"
+#include "stdio-util.h"
+#include "string-table.h"
+#include "string-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 (IN_SET(sig, SIGKILL, 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, sigset_t *old, ...) {
+        va_list ap;
+        sigset_t ss;
+        int r;
+
+        if (sigemptyset(&ss) < 0)
+                return -errno;
+
+        va_start(ap, old);
+        r = sigset_add_many_ap(&ss, ap);
+        va_end(ap);
+
+        if (r < 0)
+                return r;
+
+        if (sigprocmask(how, &ss, old) < 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[STRLEN("RTMIN+") + DECIMAL_STR_MAX(int) + 1];
+        const char *name;
+
+        name = __signal_to_string(signo);
+        if (name)
+                return name;
+
+        if (signo >= SIGRTMIN && signo <= SIGRTMAX)
+                xsprintf(buf, "RTMIN+%d", signo - SIGRTMIN);
+        else
+                xsprintf(buf, "%d", signo);
+
+        return buf;
+}
+
+int signal_from_string(const char *s) {
+        const char *p;
+        int signo, r;
+
+        /* Check that the input is a signal number. */
+        if (safe_atoi(s, &signo) >= 0) {
+                if (SIGNAL_VALID(signo))
+                        return signo;
+                else
+                        return -ERANGE;
+        }
+
+        /* Drop "SIG" prefix. */
+        if (startswith(s, "SIG"))
+                s += 3;
+
+        /* Check that the input is a signal name. */
+        signo = __signal_from_string(s);
+        if (signo > 0)
+                return signo;
+
+        /* Check that the input is RTMIN or
+         * RTMIN+n (0 <= n <= SIGRTMAX-SIGRTMIN). */
+        p = startswith(s, "RTMIN");
+        if (p) {
+                if (*p == '\0')
+                        return SIGRTMIN;
+                if (*p != '+')
+                        return -EINVAL;
+
+                r = safe_atoi(p, &signo);
+                if (r < 0)
+                        return r;
+
+                if (signo < 0 || signo > SIGRTMAX - SIGRTMIN)
+                        return -ERANGE;
+
+                return signo + SIGRTMIN;
+        }
+
+        /* Check that the input is RTMAX or
+         * RTMAX-n (0 <= n <= SIGRTMAX-SIGRTMIN). */
+        p = startswith(s, "RTMAX");
+        if (p) {
+                if (*p == '\0')
+                        return SIGRTMAX;
+                if (*p != '-')
+                        return -EINVAL;
+
+                r = safe_atoi(p, &signo);
+                if (r < 0)
+                        return r;
+
+                if (signo > 0 || signo < SIGRTMIN - SIGRTMAX)
+                        return -ERANGE;
+
+                return signo + SIGRTMAX;
+        }
+
+        return -EINVAL;
+}
+
+void nop_signal_handler(int sig) {
+        /* nothing here */
+}