From 04a8f3ceedefa63f9344311e5ff05ab3ce754fda Mon Sep 17 00:00:00 2001 From: dimitri staessens Date: Thu, 7 Jul 2016 15:12:42 +0200 Subject: lib: Add lockfile The pid of the IRMd is stored in a lockfile in shared memory. This makes checking if the IRMd is running independent of the configuration, as previously the IRMd pid was stored at the end of the shm_du_map, which could not be read by an IRMd that would be compiled with different configuration options. Also corrects some unnecessary includes Fixes #21. --- src/ipcpd/local/main.c | 1 + src/irmd/main.c | 32 ++++++---- src/lib/CMakeLists.txt | 1 + src/lib/lockfile.c | 170 +++++++++++++++++++++++++++++++++++++++++++++++++ src/lib/shm_ap_rbuff.c | 14 ++-- src/lib/shm_du_map.c | 10 +-- 6 files changed, 203 insertions(+), 25 deletions(-) create mode 100644 src/lib/lockfile.c (limited to 'src') diff --git a/src/ipcpd/local/main.c b/src/ipcpd/local/main.c index ae75ae5e..fee7fd22 100644 --- a/src/ipcpd/local/main.c +++ b/src/ipcpd/local/main.c @@ -38,6 +38,7 @@ #include +#include #include #include #include diff --git a/src/irmd/main.c b/src/irmd/main.c index 1f72fa1a..c1481a67 100644 --- a/src/irmd/main.c +++ b/src/irmd/main.c @@ -31,6 +31,7 @@ #include #include #include +#include #include #include #include @@ -106,6 +107,7 @@ struct irm { pthread_rwlock_t flows_lock; enum irm_state state; + struct lockfile * lf; struct shm_du_map * dum; pthread_t * threadpool; int sockfd; @@ -1331,6 +1333,9 @@ static void irm_destroy() if (instance->dum != NULL) shm_du_map_destroy(instance->dum); + if (instance->lf != NULL) + lockfile_destroy(instance->lf); + close(instance->sockfd); pthread_rwlock_unlock(&instance->state_lock); @@ -1698,28 +1703,28 @@ static struct irm * irm_create() instance->state = IRMD_NULL; - if (access("/dev/shm/" SHM_DU_MAP_FILENAME, F_OK) != -1) { - struct shm_du_map * dum = shm_du_map_open(); - - if (dum == NULL) { - LOG_ERR("Could not examine existing shm file."); + if (access("/dev/shm/" LOCKFILE_NAME, F_OK) != -1) { + struct lockfile * lf = lockfile_open(); + if (lf == NULL) { + LOG_ERR("Failed to open existing lockfile."); free(instance); return NULL; } - if (kill(shm_du_map_owner(dum), 0) < 0) { + if (kill(lockfile_owner(lf), 0) < 0) { LOG_INFO("IRMd didn't properly shut down last time."); - shm_du_map_destroy(dum); - LOG_INFO("Stale shm file removed."); + shm_du_map_destroy(shm_du_map_open()); + LOG_INFO("Stale resources cleaned"); + lockfile_destroy(lf); } else { LOG_INFO("IRMd already running (%d), exiting.", - shm_du_map_owner(dum)); - shm_du_map_close(dum); + lockfile_owner(lf)); + lockfile_close(lf); free(instance); return NULL; } - shm_du_map_close(dum); + lockfile_close(lf); } if (pthread_rwlock_init(&instance->state_lock, NULL)) { @@ -1777,6 +1782,11 @@ static struct irm * irm_create() return NULL; } + if ((instance->lf = lockfile_create()) == NULL) { + irm_destroy(); + return NULL; + } + if ((instance->dum = shm_du_map_create()) == NULL) { irm_destroy(); return NULL; diff --git a/src/lib/CMakeLists.txt b/src/lib/CMakeLists.txt index 9c45269c..a440f7be 100644 --- a/src/lib/CMakeLists.txt +++ b/src/lib/CMakeLists.txt @@ -31,6 +31,7 @@ set(SOURCE_FILES ipcp.c irm.c list.c + lockfile.c logs.c nsm.c shm_ap_rbuff.c diff --git a/src/lib/lockfile.c b/src/lib/lockfile.c new file mode 100644 index 00000000..a93d5f17 --- /dev/null +++ b/src/lib/lockfile.c @@ -0,0 +1,170 @@ +/* + * Ouroboros - Copyright (C) 2016 + * + * Lockfile for ouroboros system + * + * Dimitri Staessens + * + * 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 2 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, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include +#include + +#define OUROBOROS_PREFIX "lockfile" + +#include + +#include +#include +#include +#include +#include +#include +#include + +#define LF_SIZE (sizeof(pid_t)) + +struct lockfile { + pid_t * api; + int fd; +}; + +struct lockfile * lockfile_create() { + struct lockfile * lf = malloc(sizeof(*lf)); + if (lf == NULL) + return NULL; + + lf->fd = shm_open(LOCKFILE_NAME, O_CREAT | O_EXCL | O_RDWR, 0666); + if (lf->fd == -1) { + LOG_DBGF("Could not create lock file."); + free(lf); + return NULL; + } + + if (fchmod(lf->fd, 0666)) { + LOG_DBGF("Failed to chmod lockfile."); + free(lf); + return NULL; + } + + if (lseek(lf->fd, LF_SIZE - 1, SEEK_SET) < 0) { + LOG_DBGF("Failed to extend lockfile."); + free(lf); + return NULL; + } + + if (write(lf->fd, "", 1) != 1) { + LOG_DBGF("Failed to finalise lockfile."); + free(lf); + return NULL; + } + + lf->api = mmap(NULL, + LF_SIZE, PROT_READ | PROT_WRITE, + MAP_SHARED, + lf->fd, + 0); + + if (lf->api == MAP_FAILED) { + LOG_DBGF("Failed to map lockfile."); + + if (shm_unlink(LOCKFILE_NAME) == -1) + LOG_DBGF("Failed to remove invalid lockfile."); + + free(lf); + return NULL; + } + + *lf->api = getpid(); + + return lf; +} + +struct lockfile * lockfile_open() { + struct lockfile * lf = malloc(sizeof(*lf)); + if (lf == NULL) + return NULL; + + lf->fd = shm_open(LOCKFILE_NAME, O_RDWR, 0666); + if (lf->fd == -1) { + LOG_DBGF("Could not open lock file."); + free(lf); + return NULL; + } + + lf->api = mmap(NULL, + LF_SIZE, PROT_READ | PROT_WRITE, + MAP_SHARED, + lf->fd, + 0); + + if (lf->api == MAP_FAILED) { + LOG_DBGF("Failed to map lockfile."); + + if (shm_unlink(LOCKFILE_NAME) == -1) + LOG_DBGF("Failed to remove invalid lockfile."); + + free(lf); + return NULL; + } + + return lf; +} + +void lockfile_close(struct lockfile * lf) +{ + if (lf == NULL) { + LOG_DBGF("Bogus input. Bugging out."); + return; + } + + if (close(lf->fd) < 0) + LOG_DBGF("Couldn't close lockfile."); + + if (munmap(lf->api, LF_SIZE) == -1) + LOG_DBGF("Couldn't unmap lockfile."); + + free(lf); +} + +void lockfile_destroy(struct lockfile * lf) +{ + if (lf == NULL) { + LOG_DBGF("Bogus input. Bugging out."); + return; + } + + if (getpid() != *lf->api && kill(*lf->api, 0) == 0) { + LOG_DBGF("Only IRMd can destroy %s.", LOCKFILE_NAME); + return; + } + + if (close(lf->fd) < 0) + LOG_DBGF("Couldn't close lockfile."); + + if (munmap(lf->api, LF_SIZE) == -1) + LOG_DBGF("Couldn't unmap lockfile."); + + if (shm_unlink(LOCKFILE_NAME) == -1) + LOG_DBGF("Failed to remove lockfile."); + + free(lf); +} + +pid_t lockfile_owner(struct lockfile * lf) +{ + return *lf->api; +} diff --git a/src/lib/shm_ap_rbuff.c b/src/lib/shm_ap_rbuff.c index 4eb91136..cf795601 100644 --- a/src/lib/shm_ap_rbuff.c +++ b/src/lib/shm_ap_rbuff.c @@ -26,7 +26,7 @@ #include #include -#include +#include #include #include @@ -215,7 +215,7 @@ void shm_ap_rbuff_close(struct shm_ap_rbuff * rb) void shm_ap_rbuff_destroy(struct shm_ap_rbuff * rb) { char fn[25]; - struct shm_du_map * dum = NULL; + struct lockfile * lf = NULL; if (rb == NULL) { LOG_DBGF("Bogus input. Bugging out."); @@ -223,15 +223,17 @@ void shm_ap_rbuff_destroy(struct shm_ap_rbuff * rb) } if (rb->api != getpid()) { - dum = shm_du_map_open(); - if (shm_du_map_owner(dum) == getpid()) { + lf = lockfile_open(); + if (lf == NULL) + return; + if (lockfile_owner(lf) == getpid()) { LOG_DBGF("Ringbuffer %d destroyed by IRMd %d.", rb->api, getpid()); - shm_du_map_close(dum); + lockfile_close(lf); } else { LOG_ERR("AP-I %d tried to destroy rbuff owned by %d.", getpid(), rb->api); - shm_du_map_close(dum); + lockfile_close(lf); return; } } diff --git a/src/lib/shm_du_map.c b/src/lib/shm_du_map.c index 53959676..01d1e23d 100644 --- a/src/lib/shm_du_map.c +++ b/src/lib/shm_du_map.c @@ -29,9 +29,11 @@ #include #include #include +#include #include #include #include +#include #include #define OUROBOROS_PREFIX "shm_du_map" @@ -270,14 +272,6 @@ struct shm_du_map * shm_du_map_open() return dum; } -pid_t shm_du_map_owner(struct shm_du_map * dum) -{ - if (dum == NULL) - return -1; - - return *dum->api; -} - void * shm_du_map_sanitize(void * o) { struct shm_du_map * dum = (struct shm_du_map *) o; -- cgit v1.2.3