From 5d1ce25728856956c1fbfe05b491067f83bd2216 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Mon, 25 Apr 2016 00:31:24 +0200 Subject: sd-journal: add API for opening journal files or directories by fd Also, expose this via the "journalctl --file=-" syntax for STDIN. This feature remains undocumented though, as it is probably not too useful in real-life as this still requires fds that support mmaping and seeking, i.e. does not work for pipes, for which reading from STDIN is most commonly used. --- src/journal/sd-journal.c | 259 ++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 220 insertions(+), 39 deletions(-) (limited to 'src/journal/sd-journal.c') diff --git a/src/journal/sd-journal.c b/src/journal/sd-journal.c index 5104bc3e01..0798247326 100644 --- a/src/journal/sd-journal.c +++ b/src/journal/sd-journal.c @@ -1233,14 +1233,37 @@ static bool file_type_wanted(int flags, const char *filename) { return false; } -static int add_any_file(sd_journal *j, const char *path) { +static bool path_has_prefix(sd_journal *j, const char *path, const char *prefix) { + assert(j); + assert(path); + assert(prefix); + + if (j->toplevel_fd >= 0) + return false; + + return path_startswith(path, prefix); +} + +static const char *skip_slash(const char *p) { + + if (!p) + return NULL; + + while (*p == '/') + p++; + + return p; +} + +static int add_any_file(sd_journal *j, int fd, const char *path) { JournalFile *f = NULL; + bool close_fd = false; int r, k; assert(j); - assert(path); + assert(fd >= 0 || path); - if (ordered_hashmap_get(j->files, path)) + if (path && ordered_hashmap_get(j->files, path)) return 0; if (ordered_hashmap_size(j->files) >= JOURNAL_FILES_MAX) { @@ -1249,8 +1272,24 @@ static int add_any_file(sd_journal *j, const char *path) { goto fail; } - r = journal_file_open(path, O_RDONLY, 0, false, false, NULL, j->mmap, NULL, NULL, &f); + if (fd < 0 && j->toplevel_fd >= 0) { + + /* If there's a top-level fd defined, open the file relative to this now. (Make the path relative, + * explicitly, since otherwise openat() ignores the first argument.) */ + + fd = openat(j->toplevel_fd, skip_slash(path), O_RDONLY|O_CLOEXEC); + if (fd < 0) { + r = log_debug_errno(errno, "Failed to open journal file %s: %m", path); + goto fail; + } + + close_fd = true; + } + + r = journal_file_open(fd, path, O_RDONLY, 0, false, false, NULL, j->mmap, NULL, NULL, &f); if (r < 0) { + if (close_fd) + safe_close(fd); log_debug_errno(r, "Failed to open journal file %s: %m", path); goto fail; } @@ -1259,10 +1298,16 @@ static int add_any_file(sd_journal *j, const char *path) { r = ordered_hashmap_put(j->files, f->path, f); if (r < 0) { + f->close_fd = close_fd; (void) journal_file_close(f); goto fail; } + if (!j->has_runtime_files && path_has_prefix(j, f->path, "/run")) + j->has_runtime_files = true; + else if (!j->has_persistent_files && path_has_prefix(j, f->path, "/var")) + j->has_persistent_files = true; + log_debug("File %s added.", f->path); check_network(j, f->fd); @@ -1286,18 +1331,14 @@ static int add_file(sd_journal *j, const char *prefix, const char *filename) { assert(prefix); assert(filename); - if (j->no_new_files || - !file_type_wanted(j->flags, filename)) + if (j->no_new_files) return 0; - path = strjoina(prefix, "/", filename); - - if (!j->has_runtime_files && path_startswith(path, "/run/log/journal")) - j->has_runtime_files = true; - else if (!j->has_persistent_files && path_startswith(path, "/var/log/journal")) - j->has_persistent_files = true; + if (!file_type_wanted(j->flags, filename)) + return 0; - return add_any_file(j, path); + path = strjoina(prefix, "/", filename); + return add_any_file(j, -1, path); } static void remove_file(sd_journal *j, const char *prefix, const char *filename) { @@ -1373,21 +1414,33 @@ static int add_directory(sd_journal *j, const char *prefix, const char *dirname) assert(j); assert(prefix); - assert(dirname); - log_debug("Considering %s/%s.", prefix, dirname); + /* Adds a journal file directory to watch. If the directory is already tracked this updates the inotify watch + * and reenumerates directory contents */ - if ((j->flags & SD_JOURNAL_LOCAL_ONLY) && - !(dirname_is_machine_id(dirname) > 0 || path_startswith(prefix, "/run"))) - return 0; - - path = strjoin(prefix, "/", dirname, NULL); + if (dirname) + path = strjoin(prefix, "/", dirname, NULL); + else + path = strdup(prefix); if (!path) { r = -ENOMEM; goto fail; } - d = opendir(path); + log_debug("Considering directory %s.", path); + + /* We consider everything local that is in a directory for the local machine ID, or that is stored in /run */ + if ((j->flags & SD_JOURNAL_LOCAL_ONLY) && + !((dirname && dirname_is_machine_id(dirname) > 0) || path_has_prefix(j, path, "/run"))) + return 0; + + + if (j->toplevel_fd < 0) + d = opendir(path); + else + /* Open the specified directory relative to the the toplevel fd. Enforce that the path specified is + * relative, by dropping the initial slash */ + d = xopendirat(j->toplevel_fd, skip_slash(path), 0); if (!d) { r = log_debug_errno(errno, "Failed to open directory %s: %m", path); goto fail; @@ -1419,6 +1472,7 @@ static int add_directory(sd_journal *j, const char *prefix, const char *dirname) return 0; if (m->wd <= 0 && j->inotify_fd >= 0) { + /* Watch this directory, if it not being watched yet. */ m->wd = inotify_add_watch_fd(j->inotify_fd, dirfd(d), IN_CREATE|IN_MOVED_TO|IN_MODIFY|IN_ATTRIB|IN_DELETE| @@ -1441,7 +1495,7 @@ static int add_directory(sd_journal *j, const char *prefix, const char *dirname) return 0; fail: - k = journal_put_error(j, r, path ?: dirname); + k = journal_put_error(j, r, path ?: prefix); if (k < 0) return k; @@ -1449,28 +1503,62 @@ fail: } static int add_root_directory(sd_journal *j, const char *p, bool missing_ok) { + _cleanup_closedir_ DIR *d = NULL; struct dirent *de; Directory *m; int r, k; assert(j); - assert(p); - if ((j->flags & SD_JOURNAL_RUNTIME_ONLY) && - !path_startswith(p, "/run")) - return -EINVAL; + /* Adds a root directory to our set of directories to use. If the root directory is already in the set, we + * update the inotify logic, and renumerate the directory entries. This call may hence be called to initially + * populate the set, as well as to update it later. */ - if (j->prefix) - p = strjoina(j->prefix, p); + if (p) { + /* If there's a path specified, use it. */ - d = opendir(p); - if (!d) { - if (errno == ENOENT && missing_ok) - return 0; + if ((j->flags & SD_JOURNAL_RUNTIME_ONLY) && + !path_has_prefix(j, p, "/run")) + return -EINVAL; - r = log_debug_errno(errno, "Failed to open root directory %s: %m", p); - goto fail; + if (j->prefix) + p = strjoina(j->prefix, p); + + if (j->toplevel_fd < 0) + d = opendir(p); + else + d = xopendirat(j->toplevel_fd, skip_slash(p), 0); + + if (!d) { + if (errno == ENOENT && missing_ok) + return 0; + + r = log_debug_errno(errno, "Failed to open root directory %s: %m", p); + goto fail; + } + } else { + int dfd; + + /* If there's no path specified, then we use the top-level fd itself. We duplicate the fd here, since + * opendir() will take possession of the fd, and close it, which we don't want. */ + + p = "."; /* store this as "." in the directories hashmap */ + + dfd = fcntl(j->toplevel_fd, F_DUPFD_CLOEXEC, 3); + if (dfd < 0) { + r = -errno; + goto fail; + } + + d = fdopendir(dfd); + if (!d) { + r = -errno; + safe_close(dfd); + goto fail; + } + + rewinddir(d); } m = hashmap_get(j->directories_by_path, p); @@ -1482,6 +1570,7 @@ static int add_root_directory(sd_journal *j, const char *p, bool missing_ok) { } m->is_root = true; + m->path = strdup(p); if (!m->path) { free(m); @@ -1585,8 +1674,7 @@ static int add_current_paths(sd_journal *j) { assert(j); assert(j->no_new_files); - /* Simply adds all directories for files we have open as - * "root" directories. We don't expect errors here, so we + /* Simply adds all directories for files we have open as directories. We don't expect errors here, so we * treat them as fatal. */ ORDERED_HASHMAP_FOREACH(f, j->files, i) { @@ -1597,7 +1685,7 @@ static int add_current_paths(sd_journal *j) { if (!dir) return -ENOMEM; - r = add_root_directory(j, dir, true); + r = add_directory(j, dir, NULL); if (r < 0) return r; } @@ -1625,6 +1713,7 @@ static sd_journal *journal_new(int flags, const char *path) { return NULL; j->original_pid = getpid(); + j->toplevel_fd = -1; j->inotify_fd = -1; j->flags = flags; j->data_threshold = DEFAULT_DATA_THRESHOLD; @@ -1735,7 +1824,6 @@ _public_ int sd_journal_open_directory(sd_journal **ret, const char *path, int f fail: sd_journal_close(j); - return r; } @@ -1752,7 +1840,7 @@ _public_ int sd_journal_open_files(sd_journal **ret, const char **paths, int fla return -ENOMEM; STRV_FOREACH(path, paths) { - r = add_any_file(j, *path); + r = add_any_file(j, -1, *path); if (r < 0) goto fail; } @@ -1764,7 +1852,93 @@ _public_ int sd_journal_open_files(sd_journal **ret, const char **paths, int fla fail: sd_journal_close(j); + return r; +} + +_public_ int sd_journal_open_directory_fd(sd_journal **ret, int fd, int flags) { + sd_journal *j; + struct stat st; + int r; + + assert_return(ret, -EINVAL); + assert_return(fd >= 0, -EBADF); + assert_return(flags == 0, -EINVAL); + + if (fstat(fd, &st) < 0) + return -errno; + + if (!S_ISDIR(st.st_mode)) + return -EBADFD; + + j = journal_new(flags, NULL); + if (!j) + return -ENOMEM; + j->toplevel_fd = fd; + + r = add_root_directory(j, NULL, false); + if (r < 0) + goto fail; + + *ret = j; + return 0; + +fail: + sd_journal_close(j); + return r; +} + +_public_ int sd_journal_open_files_fd(sd_journal **ret, int fds[], unsigned n_fds, int flags) { + Iterator iterator; + JournalFile *f; + sd_journal *j; + unsigned i; + int r; + + assert_return(ret, -EINVAL); + assert_return(n_fds > 0, -EBADF); + assert_return(flags == 0, -EINVAL); + + j = journal_new(flags, NULL); + if (!j) + return -ENOMEM; + + for (i = 0; i < n_fds; i++) { + struct stat st; + + if (fds[i] < 0) { + r = -EBADF; + goto fail; + } + + if (fstat(fds[i], &st) < 0) { + r = -errno; + goto fail; + } + + if (!S_ISREG(st.st_mode)) { + r = -EBADFD; + goto fail; + } + + r = add_any_file(j, fds[i], NULL); + if (r < 0) + goto fail; + } + + j->no_new_files = true; + j->no_inotify = true; + + *ret = j; + return 0; + +fail: + /* If we fail, make sure we don't take possession of the files we managed to make use of successfuly, and they + * remain open */ + ORDERED_HASHMAP_FOREACH(f, j->files, iterator) + f->close_fd = false; + + sd_journal_close(j); return r; } @@ -2091,6 +2265,9 @@ _public_ int sd_journal_get_fd(sd_journal *j) { assert_return(j, -EINVAL); assert_return(!journal_pid_changed(j), -ECHILD); + if (j->no_inotify) + return -EMEDIUMTYPE; + if (j->inotify_fd >= 0) return j->inotify_fd; @@ -2098,10 +2275,14 @@ _public_ int sd_journal_get_fd(sd_journal *j) { if (r < 0) return r; + log_debug("Reiterating files to get inotify watches established"); + /* Iterate through all dirs again, to add them to the * inotify */ if (j->no_new_files) r = add_current_paths(j); + else if (j->toplevel_fd >= 0) + r = add_root_directory(j, NULL, false); else if (j->path) r = add_root_directory(j, j->path, true); else -- cgit v1.2.3-54-g00ecf