initial session backup implementation

1 files changed, 169 insertions, 8 deletions

diff --git a/accel-pppd/main.c b/accel-pppd/main.c
index e153caf4..9e515564 100644
--- a/accel-pppd/main.c
+++ b/accel-pppd/main.c
@@ -4,6 +4,11 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <errno.h>
+#include <fcntl.h>
+#include <time.h>
+#include <limits.h>
+#include <malloc.h>
+#include <dirent.h>
 #include <sys/stat.h>
 #include <sys/mman.h>
 #include <sys/resource.h>
@@ -13,9 +18,16 @@
 #include "memdebug.h"
 #include "log.h"
 #include "events.h"
+#include "backup.h"
+
+#ifndef ARG_MAX
+#define ARG_MAX 128*1024
+#endif
 
 static char *pid_file;
 static char *conf_file;
+static char *conf_dump;
+static char *exec_file;
 
 static void change_limits(void)
 {
@@ -50,19 +62,138 @@ static void config_reload_notify(int r)
 	if (!r)
 		triton_event_fire(EV_CONFIG_RELOAD, NULL);
 }
+
 static void config_reload(int num)
 {
 	triton_conf_reload(config_reload_notify);
 }
 
+static void close_all_fd(void)
+{
+	DIR *dirp;
+	struct dirent ent, *res;
+	char path[128];
+
+	sprintf(path, "/proc/%u/fd", getpid());
+	
+	dirp = opendir(path);
+	if (!dirp)
+		return;
+
+	while (1) {
+		if (readdir_r(dirp, &ent, &res))
+			return;
+		if (!res)
+			break;
+		close((unsigned long)atol(ent.d_name));
+	}
+
+	closedir(dirp);
+}
+
+void core_restart(int soft)
+{
+	char fname[128];
+	int fd, n;
+	char cmdline[ARG_MAX];
+	char *args[16];
+	char *ptr = cmdline, *endptr;
+	sigset_t set;
+
+	if (fork()) {
+		close_all_fd();
+		return;
+	}
+
+	sigfillset(&set);
+	pthread_sigmask(SIG_SETMASK, &set, NULL);
+
+	sprintf(fname, "/proc/%i/cmdline", getpid());
+
+	fd = open(fname, O_RDONLY);
+	n = read(fd, cmdline, ARG_MAX);
+
+	endptr = ptr + n;
+
+	n = 0;
+	while (ptr < endptr) {
+		args[n++] = ptr;
+		while (ptr < endptr && *ptr++);
+	}
+
+	args[n++] = NULL;
+	
+#ifdef USE_BACKUP
+	if (soft)
+		backup_restore_fd();
+	else
+#endif
+	if (fork()) {
+		close_all_fd();
+		_exit(0);
+	}
+
+
+	while (1) {
+		sleep(3);
+		execv(args[0], args);
+	}
+}
+
+static void sigsegv(int num)
+{
+	char cmd[PATH_MAX];
+	char fname[PATH_MAX];
+	struct rlimit lim;
+
+#ifdef USE_BACKUP
+	core_restart(1);
+#else
+	core_restart(0);
+#endif
+
+	if (conf_dump) {
+		FILE *f;
+		unsigned int t = time(NULL);
+		sprintf(fname, "%s/cmd-%u", conf_dump, t);
+		f = fopen(fname, "w");
+		if (!f)
+			goto out;
+		fprintf(f, "thread apply all bt full\ndetach\nquit\n");
+		fclose(f);
+
+		sprintf(cmd, "gdb -x %s %s %d > %s/dump-%u", fname, exec_file, getpid(), conf_dump, t);
+		system(cmd);
+		unlink(fname);
+	
+		lim.rlim_cur = RLIM_INFINITY;
+		lim.rlim_max = RLIM_INFINITY;
+
+		setrlimit(RLIMIT_CORE, &lim);
+	
+		chdir(conf_dump);
+	}
+
+out:
+	abort();
+}
+
 int main(int argc, char **argv)
 {
 	sigset_t set;
-	int i, sig, goto_daemon = 0;
+	int i, sig, goto_daemon = 0, len;
+	pid_t pid = 0;
+	struct sigaction sa;
+	int pagesize = sysconf(_SC_PAGE_SIZE);
+#ifdef USE_BACKUP
+	int internal = 0;
+#endif
 
 	if (argc < 2)
 		goto usage;
 
+	exec_file = argv[0];
+
 	for(i = 1; i < argc; i++) {
 		if (!strcmp(argv[i], "-d"))
 			goto_daemon = 1;
@@ -74,16 +205,38 @@ int main(int argc, char **argv)
 			if (i == argc - 1)
 				goto usage;
 			conf_file = argv[++i];
+		} else if (!strcmp(argv[i], "--dump")) {
+			if (i == argc - 1)
+				goto usage;
+			len = (strlen(argv[i + 1]) / pagesize + 1) * pagesize;
+			conf_dump = memalign(pagesize, len);
+			strcpy(conf_dump, argv[++i]);
+			mprotect(conf_dump, len, PROT_READ);
 		}
 	}
 
 	if (!conf_file)
 		goto usage;
+	
+	if (pid_file) {
+		FILE *f = fopen(pid_file, "r");
+		if (f) {
+			fscanf(f, "%u", &pid);
+			fclose(f);
+		}
+#ifdef USE_BACKUP
+		internal = pid == getppid();
+#endif
+		/*if (pid) {
+			printf("%i %i %i\n", pid, getppid(), getpid());
+			return 0;
+		}*/
+	}
 
 	if (triton_init(conf_file))
 		_exit(EXIT_FAILURE);
 
-	if (goto_daemon) {
+	if (goto_daemon && pid != getpid()) {
 		/*pid_t pid = fork();
 		if (pid > 0)
 			_exit(EXIT_SUCCESS);
@@ -121,15 +274,19 @@ int main(int argc, char **argv)
 
 	triton_run();
 
-	sigfillset(&set);
 
-	struct sigaction sa = {
-		.sa_handler = config_reload,
-		.sa_mask = set,
-	};
+	sigfillset(&set);
 
+	memset(&sa, 0, sizeof(sa));
+	sa.sa_handler = config_reload;
+	sa.sa_mask = set;
 	sigaction(SIGUSR1, &sa, NULL);
+	
+	sa.sa_handler = sigsegv;
+	sa.sa_mask = set;
+	sigaction(SIGSEGV, &sa, NULL);
 
+	
 	sigdelset(&set, SIGKILL);
 	sigdelset(&set, SIGSTOP);
 	sigdelset(&set, SIGSEGV);
@@ -151,7 +308,11 @@ int main(int argc, char **argv)
 	sigaddset(&set, SIGILL);
 	sigaddset(&set, SIGFPE);
 	sigaddset(&set, SIGBUS);
-	
+
+#ifdef USE_BACKUP
+	backup_restore(internal);
+#endif
+
 	sigwait(&set, &sig);
 	log_info1("terminate, sig = %i\n", sig);