diff --git a/cmd/ifupdown.c b/cmd/ifupdown.c index 50b9e33..bf19a0e 100644 --- a/cmd/ifupdown.c +++ b/cmd/ifupdown.c @@ -34,6 +34,7 @@ static bool up; static struct lif_execute_opts exec_opts = { .executor_path = EXECUTOR_PATH, .interfaces_file = INTERFACES_FILE, + .state_file = STATE_FILE, }; void @@ -67,9 +68,65 @@ is_ifdown() return false; } +int +acquire_state_lock(const char *state_path, const char *lifname) +{ + if (exec_opts.mock || exec_opts.no_lock) + return -1; + + char lockpath[4096] = {}; + + snprintf(lockpath, sizeof lockpath, "%s.%s.lock", state_path, lifname); + + int fd = open(lockpath, O_CREAT | O_WRONLY | O_TRUNC); + if (fd < 0) + { + fprintf(stderr, "opening lockfile %s: %s\n", lockpath, strerror(errno)); + return -1; + } + + int flags = fcntl(fd, F_GETFD); + if (flags < 0) + { + close(fd); + + fprintf(stderr, "getting flags for lockfile: %s\n", strerror(errno)); + return -1; + } + + flags |= FD_CLOEXEC; + if (fcntl(fd, F_SETFD, flags) == -1) + { + close(fd); + + fprintf(stderr, "setting lockfile close-on-exec: %s\n", strerror(errno)); + return -1; + } + + struct flock fl = { + .l_type = F_WRLCK, + .l_whence = SEEK_SET + }; + + if (exec_opts.verbose) + fprintf(stderr, "ifupdown: acquiring lock on %s\n", lockpath); + + if (fcntl(fd, F_SETLKW, &fl) == -1) + { + close(fd); + + fprintf(stderr, "locking lockfile: %s\n", strerror(errno)); + return -1; + } + + return fd; +} + bool change_interface(struct lif_interface *iface, struct lif_dict *collection, struct lif_dict *state, const char *ifname) { + int lockfd = acquire_state_lock(exec_opts.state_file, ifname); + if (exec_opts.verbose) { fprintf(stderr, "%s: changing state of interface %s to '%s'\n", @@ -80,9 +137,16 @@ change_interface(struct lif_interface *iface, struct lif_dict *collection, struc { fprintf(stderr, "%s: failed to change interface %s state to '%s'\n", argv0, ifname, up ? "up" : "down"); + + if (lockfd != -1) + close(lockfd); + return false; } + if (lockfd != -1) + close(lockfd); + return true; } @@ -114,54 +178,6 @@ change_auto_interfaces(struct lif_dict *collection, struct lif_dict *state, stru return true; } -int -acquire_state_lock(const char *state_path) -{ - char lockpath[4096] = {}; - - snprintf(lockpath, sizeof lockpath, "%s.lock", state_path); - - int fd = open(lockpath, O_CREAT | O_WRONLY | O_TRUNC); - if (fd < 0) - { - fprintf(stderr, "opening lockfile %s: %s\n", lockpath, strerror(errno)); - return -1; - } - - int flags = fcntl(fd, F_GETFD); - if (flags < 0) - { - close(fd); - - fprintf(stderr, "getting flags for lockfile: %s\n", strerror(errno)); - return -1; - } - - flags |= FD_CLOEXEC; - if (fcntl(fd, F_SETFD, flags) == -1) - { - close(fd); - - fprintf(stderr, "setting lockfile close-on-exec: %s\n", strerror(errno)); - return -1; - } - - struct flock fl = { - .l_type = F_WRLCK, - .l_whence = SEEK_SET - }; - - if (fcntl(fd, F_SETLKW, &fl) == -1) - { - close(fd); - - fprintf(stderr, "locking lockfile: %s\n", strerror(errno)); - return -1; - } - - return fd; -} - int ifupdown_main(int argc, char *argv[]) { @@ -185,9 +201,6 @@ ifupdown_main(int argc, char *argv[]) {NULL, 0, 0, 0} }; struct match_options match_opts = {}; - char *state_file = STATE_FILE; - int lockfd = -1; - bool no_lock = false; for (;;) { @@ -215,7 +228,7 @@ ifupdown_main(int argc, char *argv[]) match_opts.exclude_pattern = optarg; break; case 'S': - state_file = optarg; + exec_opts.state_file = optarg; break; case 'n': exec_opts.mock = true; @@ -230,17 +243,14 @@ ifupdown_main(int argc, char *argv[]) case 'f': break; case 'L': - no_lock = true; + exec_opts.no_lock = true; break; } } - if (!exec_opts.mock && !no_lock) - lockfd = acquire_state_lock(state_file); - - if (!lif_state_read_path(&state, state_file)) + if (!lif_state_read_path(&state, exec_opts.state_file)) { - fprintf(stderr, "%s: could not parse %s\n", argv0, state_file); + fprintf(stderr, "%s: could not parse %s\n", argv0, exec_opts.state_file); return EXIT_FAILURE; } @@ -300,15 +310,12 @@ ifupdown_main(int argc, char *argv[]) return EXIT_FAILURE; } - if (!exec_opts.mock && !lif_state_write_path(&state, state_file)) + if (!exec_opts.mock && !lif_state_write_path(&state, exec_opts.state_file)) { - fprintf(stderr, "%s: could not update %s\n", argv0, state_file); + fprintf(stderr, "%s: could not update %s\n", argv0, exec_opts.state_file); return EXIT_FAILURE; } - if (lockfd >= 0) - close(lockfd); - return EXIT_SUCCESS; } diff --git a/libifupdown/execute.h b/libifupdown/execute.h index 3fbde45..625171d 100644 --- a/libifupdown/execute.h +++ b/libifupdown/execute.h @@ -22,8 +22,10 @@ struct lif_execute_opts { bool verbose; bool mock; + bool no_lock; const char *executor_path; const char *interfaces_file; + const char *state_file; }; extern bool lif_execute_fmt(const struct lif_execute_opts *opts, char *const envp[], const char *fmt, ...);