X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=server.c;h=be97516f1e66272cf53abde69122d80906d53159;hp=1e4caf08c90d0e04233a987f6e520e19850c20c5;hb=a4eb244ecdf9aaa0f167b3c91d3e276bde99d681;hpb=46f2f102fa22ddffe515546e7db21cf208db0d90 diff --git a/server.c b/server.c index 1e4caf08..be97516f 100644 --- a/server.c +++ b/server.c @@ -14,7 +14,7 @@ * * * - The main programs: \ref server.c, \ref audiod.c, \ref client.c, - * \ref audioc.c, \ref fsck.c, \ref afh.c + * \ref audioc.c, \ref afh.c * - Server: \ref server_command, \ref sender, * - Audio file selector: \ref audio_format_handler, \ref mood, \ref afs_table, * - Client: \ref receiver, \ref receiver_node, \ref filter, \ref filter_node. @@ -47,7 +47,6 @@ * - Time: \ref time.c, * - Spawning processes: \ref exec.c, * - Inter process communication: \ref ipc.c, - * - The object storage layer: \ref osl.c, * - Blob tables: \ref blob.c, * - The error subssystem: \ref error.h. * - Access control for paraslash senders: \ref acl.c, \ref acl.h. @@ -55,19 +54,22 @@ * Low-level data structures: * * - Doubly linked lists: \ref list.h, - * - Red-black trees: \ref rbtree.h, \ref rbtree.c, * - Ring buffer: \ref ringbuffer.c, \ref ringbuffer.h, * - Hashing: \ref hash.h, \ref sha1.h, \ref sha1.c, * - Crypto: \ref crypt.c. - * + * - Forward error correction: \ref fec.c */ #include #include #include +#include +#include +#include #include "para.h" #include "error.h" +#include "crypt.h" #include "server.cmdline.h" #include "afh.h" #include "string.h" @@ -291,17 +293,33 @@ static void signal_post_select(struct sched *s, struct task *t) if (pid != mmd->afs_pid) continue; PARA_EMERG_LOG("fatal: afs died\n"); - goto genocide; + kill(0, SIGTERM); + goto cleanup; } break; /* die on sigint/sigterm. Kill all children too. */ case SIGINT: case SIGTERM: PARA_EMERG_LOG("terminating on signal %d\n", st->signum); -genocide: kill(0, SIGTERM); + /* + * We must wait for afs because afs catches SIGINT/SIGTERM. + * Before reacting to the signal, afs might want to use the + * shared memory area and the mmd mutex. If we destroy this + * mutex too early and afs tries to lock the shared memory + * area, the call to mutex_lock() will fail and terminate the + * afs process. This leads to dirty osl tables. + * + * There's no such problem with the other children of the + * server process (the command handlers) as these reset their + * SIGINT/SIGTERM handlers to the default action, i.e. these + * processes get killed immediately by the above kill(). + */ + PARA_INFO_LOG("waiting for afs (pid %d) to die\n", + (int)mmd->afs_pid); + waitpid(mmd->afs_pid, NULL, 0); +cleanup: free(mmd->afd.afhi.chunk_table); - free(mmd->afd.afhi.info_string); close_listed_fds(); mutex_destroy(mmd_mutex); shm_detach(mmd); @@ -318,25 +336,15 @@ static void init_signal_task(void) st->task.post_select = signal_post_select; sprintf(st->task.status, "signal task"); + PARA_NOTICE_LOG("setting up signal handling\n"); st->fd = para_signal_init(); /* always successful */ - - PARA_NOTICE_LOG("setting up signal handlers\n"); - if (para_install_sighandler(SIGINT) < 0) - goto err; - if (para_install_sighandler(SIGTERM) < 0) - goto err; - if (para_install_sighandler(SIGHUP) < 0) - goto err; - if (para_install_sighandler(SIGCHLD) < 0) - goto err; - if (signal(SIGPIPE, SIG_IGN) == SIG_ERR) - goto err; + para_install_sighandler(SIGINT); + para_install_sighandler(SIGTERM); + para_install_sighandler(SIGHUP); + para_install_sighandler(SIGCHLD); + para_sigaction(SIGPIPE, SIG_IGN); add_close_on_fork_list(st->fd); register_task(&st->task); - return; -err: - PARA_EMERG_LOG("could not install signal handlers\n"); - exit(EXIT_FAILURE); } static void command_pre_select(struct sched *s, struct task *t) @@ -352,6 +360,7 @@ static void command_post_select(struct sched *s, struct task *t) int new_fd, ret, i; char *peer_name; pid_t child_pid; + uint32_t *chunk_table; if (!FD_ISSET(sct->listen_fd, &s->rfds)) return; @@ -363,7 +372,16 @@ static void command_post_select(struct sched *s, struct task *t) PARA_INFO_LOG("got connection from %s, forking\n", peer_name); mmd->num_connects++; mmd->active_connections++; - random(); + /* + * The chunk table is a pointer located in the mmd struct that points + * to dynamically allocated memory, i.e. it must be freed by the parent + * and the child. However, as the mmd struct is in a shared memory + * area, there's no guarantee that after the fork this pointer is still + * valid in child context. As it is not used in the child anyway, we + * save it to a local variable before the fork and free the memory via + * that copy in the child directly after the fork. + */ + chunk_table = mmd->afd.afhi.chunk_table; child_pid = fork(); if (child_pid < 0) { ret = -ERRNO_TO_PARA_ERROR(errno); @@ -374,6 +392,8 @@ static void command_post_select(struct sched *s, struct task *t) /* parent keeps accepting connections */ return; } + /* mmd might already have changed at this point */ + free(chunk_table); alarm(ALARM_TIMEOUT); close_listed_fds(); para_signal_shutdown(); @@ -416,35 +436,6 @@ err: exit(EXIT_FAILURE); } -static void init_random_seed(void) -{ - unsigned int seed; - int fd, ret = para_open("/dev/urandom", O_RDONLY, 0); - - if (ret < 0) - goto err; - fd = ret; - ret = read(fd, &seed, sizeof(seed)); - if (ret < 0) { - ret = -ERRNO_TO_PARA_ERROR(errno); - goto out; - } - if (ret != sizeof(seed)) { - ret = -ERRNO_TO_PARA_ERROR(EIO); - goto out; - } - srandom(seed); - ret = 1; -out: - close(fd); - if (ret >= 0) - return; -err: - PARA_EMERG_LOG("can not seed pseudo random number generator: %s\n", - para_strerror(-ret)); - exit(EXIT_FAILURE); -} - static int init_afs(void) { int ret, afs_server_socket[2]; @@ -452,7 +443,8 @@ static int init_afs(void) ret = socketpair(PF_UNIX, SOCK_DGRAM, 0, afs_server_socket); if (ret < 0) exit(EXIT_FAILURE); - afs_socket_cookie = para_random((uint32_t)-1); + get_random_bytes_or_die((unsigned char *)&afs_socket_cookie, + sizeof(afs_socket_cookie)); mmd->afs_pid = fork(); if (mmd->afs_pid < 0) exit(EXIT_FAILURE); @@ -488,7 +480,7 @@ static void server_init(int argc, char **argv) int afs_socket; valid_fd_012(); - init_random_seed(); + init_random_seed_or_die(); /* parse command line options */ server_cmdline_parser_ext(argc, argv, &conf, ¶ms); HANDLE_VERSION_FLAG("server", conf); @@ -514,19 +506,13 @@ static void server_init(int argc, char **argv) * before the child gets a chance to ignore this signal -- only the * good die young. */ - if (signal(SIGUSR1, SIG_IGN) == SIG_ERR) { - PARA_EMERG_LOG("failed to ignore SIGUSR1\n"); - exit(EXIT_FAILURE); - } + para_sigaction(SIGUSR1, SIG_IGN); /* * We have to install a SIGCHLD handler before the afs process is being * forked off. Otherwise, para_server does not notice if afs dies before * the SIGCHLD handler has been installed by init_signal_task() below. */ - if (signal(SIGCHLD, tmp_sigchld_handler) == SIG_ERR) { - PARA_EMERG_LOG("failed to install temporary SIGCHLD handler\n"); - exit(EXIT_FAILURE); - } + para_sigaction(SIGCHLD, tmp_sigchld_handler); PARA_NOTICE_LOG("initializing the audio file selector\n"); afs_socket = init_afs(); init_signal_task();