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Diffstat (limited to 'src/util/server.c')
| -rw-r--r-- | src/util/server.c | 433 |
1 files changed, 433 insertions, 0 deletions
diff --git a/src/util/server.c b/src/util/server.c new file mode 100644 index 000000000..fd6c46531 --- /dev/null +++ b/src/util/server.c @@ -0,0 +1,433 @@ +/* + SSSD + + Servers setup routines + + Copyright (C) Andrew Tridgell 1992-2005 + Copyright (C) Martin Pool 2002 + Copyright (C) Jelmer Vernooij 2002 + Copyright (C) James J Myers 2003 <myersjj@samba.org> + Copyright (C) Simo Sorce 2008 + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#define _GNU_SOURCE +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <unistd.h> +#include "util/util.h" +#include "ldb.h" +#include "confdb/confdb.h" + +#ifdef HAVE_PRCTL +#include <sys/prctl.h> +#endif + +/******************************************************************* + Close the low 3 fd's and open dev/null in their place. +********************************************************************/ +static void close_low_fds(void) +{ +#ifndef VALGRIND + int fd; + int i; + + close(0); + close(1); + close(2); + + /* try and use up these file descriptors, so silly + library routines writing to stdout etc won't cause havoc */ + for (i=0;i<3;i++) { + fd = open("/dev/null",O_RDWR,0); + if (fd < 0) + fd = open("/dev/null",O_WRONLY,0); + if (fd < 0) { + DEBUG(0,("Can't open /dev/null\n")); + return; + } + if (fd != i) { + DEBUG(0,("Didn't get file descriptor %d\n",i)); + return; + } + } +#endif +} + +/** + Become a daemon, discarding the controlling terminal. +**/ + +void become_daemon(bool Fork) +{ + int ret; + + if (Fork) { + if (fork()) { + _exit(0); + } + } + + /* detach from the terminal */ + setsid(); + + /* chdir to / to be sure we're not on a remote filesystem */ + errno = 0; + if(chdir("/") == -1) { + ret = errno; + DEBUG(0, ("Cannot change directory (%d [%s])\n", + ret, strerror(ret))); + return; + } + + /* Close fd's 0,1,2. Needed if started by rsh */ + close_low_fds(); +} + +int pidfile(const char *path, const char *name) +{ + char pid_str[32]; + pid_t pid; + char *file; + int fd; + int ret, err; + + file = talloc_asprintf(NULL, "%s/%s.pid", path, name); + if (!file) { + return ENOMEM; + } + + fd = open(file, O_RDONLY, 0644); + err = errno; + if (fd != -1) { + + pid_str[sizeof(pid_str) -1] = '\0'; + ret = read(fd, pid_str, sizeof(pid_str) -1); + if (ret > 0) { + /* let's check the pid */ + + pid = (pid_t)atoi(pid_str); + if (pid != 0) { + errno = 0; + ret = kill(pid, 0); + /* succeeded in signaling the process -> another sssd process */ + if (ret == 0) { + close(fd); + talloc_free(file); + return EEXIST; + } + if (ret != 0 && errno != ESRCH) { + err = errno; + close(fd); + talloc_free(file); + return err; + } + } + } + + /* nothing in the file or no process */ + close(fd); + unlink(file); + + } else { + if (err != ENOENT) { + talloc_free(file); + return err; + } + } + + fd = open(file, O_CREAT | O_WRONLY | O_EXCL, 0644); + err = errno; + if (fd == -1) { + talloc_free(file); + return err; + } + talloc_free(file); + + memset(pid_str, 0, sizeof(pid_str)); + snprintf(pid_str, sizeof(pid_str) -1, "%u\n", (unsigned int) getpid()); + + ret = write(fd, pid_str, strlen(pid_str)); + err = errno; + if (ret != strlen(pid_str)) { + close(fd); + return err; + } + + close(fd); + + return 0; +} + +static void sig_hup(int sig) +{ + /* cycle log/debug files */ + return; +} + +static void sig_term(int sig) +{ +#if HAVE_GETPGRP + static int done_sigterm; + if (done_sigterm == 0 && getpgrp() == getpid()) { + DEBUG(0,("SIGTERM: killing children\n")); + done_sigterm = 1; + kill(-getpgrp(), SIGTERM); + } +#endif + exit(0); +} + +#ifndef HAVE_PRCTL +static void sig_segv_abrt(int sig) +{ +#if HAVE_GETPGRP + static int done; + if (done == 0 && getpgrp() == getpid()) { + DEBUG(0,("%s: killing children\n", strsignal(sig))); + done = 1; + kill(-getpgrp(), SIGTERM); + } +#endif /* HAVE_GETPGRP */ + exit(1); +} +#endif /* HAVE_PRCTL */ + +/* + setup signal masks +*/ +static void setup_signals(void) +{ + /* we are never interested in SIGPIPE */ + BlockSignals(true, SIGPIPE); + +#if defined(SIGFPE) + /* we are never interested in SIGFPE */ + BlockSignals(true, SIGFPE); +#endif + + /* We are no longer interested in USR1 */ + BlockSignals(true, SIGUSR1); + +#if defined(SIGUSR2) + /* We are no longer interested in USR2 */ + BlockSignals(true, SIGUSR2); +#endif + + /* POSIX demands that signals are inherited. If the invoking process has + * these signals masked, we will have problems, as we won't recieve them. */ + BlockSignals(false, SIGHUP); + BlockSignals(false, SIGTERM); + + CatchSignal(SIGHUP, sig_hup); + CatchSignal(SIGTERM, sig_term); + +#ifndef HAVE_PRCTL + /* If prctl is not defined on the system, try to handle + * some common termination signals gracefully */ + CatchSignal(SIGSEGV, sig_segv_abrt); + CatchSignal(SIGABRT, sig_segv_abrt); +#endif + +} + +/* + handle io on stdin +*/ +static void server_stdin_handler(struct tevent_context *event_ctx, + struct tevent_fd *fde, + uint16_t flags, void *private) +{ + const char *binary_name = (const char *)private; + uint8_t c; + if (read(0, &c, 1) == 0) { + DEBUG(0,("%s: EOF on stdin - terminating\n", binary_name)); +#if HAVE_GETPGRP + if (getpgrp() == getpid()) { + kill(-getpgrp(), SIGTERM); + } +#endif + exit(0); + } +} + +/* + main server helpers. +*/ + +int die_if_parent_died(void) +{ +#ifdef HAVE_PRCTL + int ret; + + errno = 0; + ret = prctl(PR_SET_PDEATHSIG, SIGTERM, 0, 0, 0); + if (ret != 0) { + ret = errno; + DEBUG(2, ("prctl failed [%d]: %s", ret, strerror(ret))); + return ret; + } +#endif + return EOK; +} + +int server_setup(const char *name, int flags, + const char *conf_entry, + struct main_context **main_ctx) +{ + struct tevent_context *event_ctx; + struct main_context *ctx; + uint16_t stdin_event_flags; + char *conf_db; + int ret = EOK; + bool dt; + bool dl; + + debug_prg_name = strdup(name); + if (!debug_prg_name) { + return ENOMEM; + } + + setenv("_SSS_LOOPS", "NO", 0); + + setup_signals(); + + /* we want default permissions on created files to be very strict, + so set our umask to 0177 */ + umask(0177); + + if (flags & FLAGS_DAEMON) { + DEBUG(3,("Becoming a daemon.\n")); + become_daemon(true); + } + + if (flags & FLAGS_PID_FILE) { + ret = pidfile(PID_PATH, name); + if (ret != EOK) { + DEBUG(0, ("Error creating pidfile! (%d [%s])\n", + ret, strerror(ret))); + return ret; + } + } + + /* Set up locale */ + setlocale (LC_ALL, ""); + bindtextdomain (PACKAGE, LOCALEDIR); + textdomain (PACKAGE); + + /* the event context is the top level structure. + * Everything else should hang off that */ + event_ctx = tevent_context_init(talloc_autofree_context()); + if (event_ctx == NULL) { + DEBUG(0,("The event context initialiaziton failed\n")); + return 1; + } + + ctx = talloc(event_ctx, struct main_context); + if (ctx == NULL) { + DEBUG(0,("Out of memory, aborting!\n")); + return ENOMEM; + } + + ctx->event_ctx = event_ctx; + + conf_db = talloc_asprintf(ctx, "%s/%s", DB_PATH, CONFDB_FILE); + if (conf_db == NULL) { + DEBUG(0,("Out of memory, aborting!\n")); + return ENOMEM; + } + + ret = confdb_init(ctx, &ctx->confdb_ctx, conf_db); + if (ret != EOK) { + DEBUG(0,("The confdb initialization failed\n")); + return ret; + } + + /* set debug level if any in conf_entry */ + ret = confdb_get_int(ctx->confdb_ctx, ctx, conf_entry, + CONFDB_SERVICE_DEBUG_LEVEL, + debug_level, &debug_level); + if (ret != EOK) { + DEBUG(0, ("Error reading from confdb (%d) [%s]\n", + ret, strerror(ret))); + return ret; + } + + /* same for debug timestamps */ + dt = (debug_timestamps != 0); + ret = confdb_get_bool(ctx->confdb_ctx, ctx, conf_entry, + CONFDB_SERVICE_DEBUG_TIMESTAMPS, + dt, &dt); + if (ret != EOK) { + DEBUG(0, ("Error reading from confdb (%d) [%s]\n", + ret, strerror(ret))); + return ret; + } + if (dt) debug_timestamps = 1; + + /* same for debug to file */ + dl = (debug_to_file != 0); + ret = confdb_get_bool(ctx->confdb_ctx, ctx, conf_entry, + CONFDB_SERVICE_DEBUG_TO_FILES, + dl, &dl); + if (ret != EOK) { + DEBUG(0, ("Error reading from confdb (%d) [%s]\n", + ret, strerror(ret))); + return ret; + } + if (dl) debug_to_file = 1; + + /* open log file if told so */ + if (debug_to_file) { + ret = open_debug_file(); + if (ret != EOK) { + DEBUG(0, ("Error setting up logging (%d) [%s]\n", + ret, strerror(ret))); + return ret; + } + } + + DEBUG(3, ("CONFDB: %s\n", conf_db)); + + if (flags & FLAGS_INTERACTIVE) { + /* terminate when stdin goes away */ + stdin_event_flags = TEVENT_FD_READ; + } else { + /* stay alive forever */ + stdin_event_flags = 0; + } + + /* catch EOF on stdin */ +#ifdef SIGTTIN + signal(SIGTTIN, SIG_IGN); +#endif + tevent_add_fd(event_ctx, event_ctx, 0, stdin_event_flags, + server_stdin_handler, discard_const(name)); + + *main_ctx = ctx; + return EOK; +} + +void server_loop(struct main_context *main_ctx) +{ + /* wait for events - this is where the server sits for most of its + life */ + tevent_loop_wait(main_ctx->event_ctx); + + /* as everything hangs off this event context, freeing it + should initiate a clean shutdown of all services */ + talloc_free(main_ctx->event_ctx); +} |