diff --git a/include/crm/common/internal.h b/include/crm/common/internal.h index a354f0cb32..ddbe67457d 100644 --- a/include/crm/common/internal.h +++ b/include/crm/common/internal.h @@ -1,360 +1,361 @@ /* * Copyright 2015-2024 the Pacemaker project contributors * * The version control history for this file may have further details. * * This source code is licensed under the GNU Lesser General Public License * version 2.1 or later (LGPLv2.1+) WITHOUT ANY WARRANTY. */ #ifndef PCMK__CRM_COMMON_INTERNAL__H #define PCMK__CRM_COMMON_INTERNAL__H #include // pid_t, getpid() #include // bool #include // uint8_t, uint64_t #include // guint, GList, GHashTable #include // xmlNode #include // do_crm_log_unlikely(), etc. #include // mainloop_io_t, struct ipc_client_callbacks #include // crm_strdup_printf() #include #include #include #include #include #include #include #include #include #include #include #ifdef __cplusplus extern "C" { #endif /* This says whether the current application is a Pacemaker daemon or not, * and is used to change default logging settings such as whether to log to * stderr, etc., as well as a few other details such as whether blackbox signal * handling is enabled. * * It is set when logging is initialized, and does not need to be set directly. */ extern bool pcmk__is_daemon; // Number of elements in a statically defined array #define PCMK__NELEM(a) ((int) (sizeof(a)/sizeof(a[0])) ) #if PCMK__ENABLE_CIBSECRETS /* internal CIB utilities (from cib_secrets.c) */ int pcmk__substitute_secrets(const char *rsc_id, GHashTable *params); #endif /* internal main loop utilities (from mainloop.c) */ int pcmk__add_mainloop_ipc(crm_ipc_t *ipc, int priority, void *userdata, const struct ipc_client_callbacks *callbacks, mainloop_io_t **source); guint pcmk__mainloop_timer_get_period(const mainloop_timer_t *timer); /* internal node-related XML utilities (from nodes.c) */ /*! * \internal * \brief Add local node name and ID to an XML node * * \param[in,out] request XML node to modify * \param[in] node The local node's name * \param[in] nodeid The local node's ID (can be 0) */ void pcmk__xe_add_node(xmlNode *xml, const char *node, int nodeid); /* internal name/value utilities (from nvpair.c) */ int pcmk__scan_nvpair(const char *input, char **name, char **value); char *pcmk__format_nvpair(const char *name, const char *value, const char *units); /* internal procfs utilities (from procfs.c) */ pid_t pcmk__procfs_pid_of(const char *name); unsigned int pcmk__procfs_num_cores(void); int pcmk__procfs_pid2path(pid_t pid, char path[], size_t path_size); bool pcmk__procfs_has_pids(void); +DIR *pcmk__procfs_fd_dir(void); void pcmk__sysrq_trigger(char t); /* internal functions related to process IDs (from pid.c) */ /*! * \internal * \brief Check whether process exists (by PID and optionally executable path) * * \param[in] pid PID of process to check * \param[in] daemon If not NULL, path component to match with procfs entry * * \return Standard Pacemaker return code * \note Particular return codes of interest include pcmk_rc_ok for alive, * ESRCH for process is not alive (verified by kill and/or executable path * match), EACCES for caller unable or not allowed to check. A result of * "alive" is less reliable when \p daemon is not provided or procfs is * not available, since there is no guarantee that the PID has not been * recycled for another process. * \note This function cannot be used to verify \e authenticity of the process. */ int pcmk__pid_active(pid_t pid, const char *daemon); int pcmk__read_pidfile(const char *filename, pid_t *pid); int pcmk__pidfile_matches(const char *filename, pid_t expected_pid, const char *expected_name, pid_t *pid); int pcmk__lock_pidfile(const char *filename, const char *name); // bitwise arithmetic utilities /*! * \internal * \brief Set specified flags in a flag group * * \param[in] function Function name of caller * \param[in] line Line number of caller * \param[in] log_level Log a message at this level * \param[in] flag_type Label describing this flag group (for logging) * \param[in] target Name of object whose flags these are (for logging) * \param[in] flag_group Flag group being manipulated * \param[in] flags Which flags in the group should be set * \param[in] flags_str Readable equivalent of \p flags (for logging) * * \return Possibly modified flag group */ static inline uint64_t pcmk__set_flags_as(const char *function, int line, uint8_t log_level, const char *flag_type, const char *target, uint64_t flag_group, uint64_t flags, const char *flags_str) { uint64_t result = flag_group | flags; if (result != flag_group) { do_crm_log_unlikely(log_level, "%s flags %#.8llx (%s) for %s set by %s:%d", ((flag_type == NULL)? "Group of" : flag_type), (unsigned long long) flags, ((flags_str == NULL)? "flags" : flags_str), ((target == NULL)? "target" : target), function, line); } return result; } /*! * \internal * \brief Clear specified flags in a flag group * * \param[in] function Function name of caller * \param[in] line Line number of caller * \param[in] log_level Log a message at this level * \param[in] flag_type Label describing this flag group (for logging) * \param[in] target Name of object whose flags these are (for logging) * \param[in] flag_group Flag group being manipulated * \param[in] flags Which flags in the group should be cleared * \param[in] flags_str Readable equivalent of \p flags (for logging) * * \return Possibly modified flag group */ static inline uint64_t pcmk__clear_flags_as(const char *function, int line, uint8_t log_level, const char *flag_type, const char *target, uint64_t flag_group, uint64_t flags, const char *flags_str) { uint64_t result = flag_group & ~flags; if (result != flag_group) { do_crm_log_unlikely(log_level, "%s flags %#.8llx (%s) for %s cleared by %s:%d", ((flag_type == NULL)? "Group of" : flag_type), (unsigned long long) flags, ((flags_str == NULL)? "flags" : flags_str), ((target == NULL)? "target" : target), function, line); } return result; } /*! * \internal * \brief Get readable string for whether specified flags are set * * \param[in] flag_group Group of flags to check * \param[in] flags Which flags in \p flag_group should be checked * * \return "true" if all \p flags are set in \p flag_group, otherwise "false" */ static inline const char * pcmk__flag_text(uint64_t flag_group, uint64_t flags) { return pcmk__btoa(pcmk_all_flags_set(flag_group, flags)); } // miscellaneous utilities (from utils.c) void pcmk__daemonize(const char *name, const char *pidfile); void pcmk__panic(const char *reason); pid_t pcmk__locate_sbd(void); void pcmk__sleep_ms(unsigned int ms); guint pcmk__create_timer(guint interval_ms, GSourceFunc fn, gpointer data); guint pcmk__timeout_ms2s(guint timeout_ms); extern int pcmk__score_red; extern int pcmk__score_green; extern int pcmk__score_yellow; /*! * \internal * \brief Allocate new zero-initialized memory, asserting on failure * * \param[in] file File where \p function is located * \param[in] function Calling function * \param[in] line Line within \p file * \param[in] nmemb Number of elements to allocate memory for * \param[in] size Size of each element * * \return Newly allocated memory of of size nmemb * size (guaranteed * not to be \c NULL) * * \note The caller is responsible for freeing the return value using \c free(). */ static inline void * pcmk__assert_alloc_as(const char *file, const char *function, uint32_t line, size_t nmemb, size_t size) { void *ptr = calloc(nmemb, size); if (ptr == NULL) { crm_abort(file, function, line, "Out of memory", FALSE, TRUE); crm_exit(CRM_EX_OSERR); } return ptr; } /*! * \internal * \brief Allocate new zero-initialized memory, asserting on failure * * \param[in] nmemb Number of elements to allocate memory for * \param[in] size Size of each element * * \return Newly allocated memory of of size nmemb * size (guaranteed * not to be \c NULL) * * \note The caller is responsible for freeing the return value using \c free(). */ #define pcmk__assert_alloc(nmemb, size) \ pcmk__assert_alloc_as(__FILE__, __func__, __LINE__, nmemb, size) /*! * \internal * \brief Resize a dynamically allocated memory block * * \param[in] ptr Memory block to resize (or NULL to allocate new memory) * \param[in] size New size of memory block in bytes (must be > 0) * * \return Pointer to resized memory block * * \note This asserts on error, so the result is guaranteed to be non-NULL * (which is the main advantage of this over directly using realloc()). */ static inline void * pcmk__realloc(void *ptr, size_t size) { void *new_ptr; // realloc(p, 0) can replace free(p) but this wrapper can't pcmk__assert(size > 0); new_ptr = realloc(ptr, size); if (new_ptr == NULL) { free(ptr); abort(); } return new_ptr; } static inline char * pcmk__getpid_s(void) { return crm_strdup_printf("%lu", (unsigned long) getpid()); } // More efficient than g_list_length(list) == 1 static inline bool pcmk__list_of_1(GList *list) { return list && (list->next == NULL); } // More efficient than g_list_length(list) > 1 static inline bool pcmk__list_of_multiple(GList *list) { return list && (list->next != NULL); } /* convenience functions for failure-related node attributes */ #define PCMK__FAIL_COUNT_PREFIX "fail-count" #define PCMK__LAST_FAILURE_PREFIX "last-failure" /*! * \internal * \brief Generate a failure-related node attribute name for a resource * * \param[in] prefix Start of attribute name * \param[in] rsc_id Resource name * \param[in] op Operation name * \param[in] interval_ms Operation interval * * \return Newly allocated string with attribute name * * \note Failure attributes are named like PREFIX-RSC#OP_INTERVAL (for example, * "fail-count-myrsc#monitor_30000"). The '#' is used because it is not * a valid character in a resource ID, to reliably distinguish where the * operation name begins. The '_' is used simply to be more comparable to * action labels like "myrsc_monitor_30000". */ static inline char * pcmk__fail_attr_name(const char *prefix, const char *rsc_id, const char *op, guint interval_ms) { CRM_CHECK(prefix && rsc_id && op, return NULL); return crm_strdup_printf("%s-%s#%s_%u", prefix, rsc_id, op, interval_ms); } static inline char * pcmk__failcount_name(const char *rsc_id, const char *op, guint interval_ms) { return pcmk__fail_attr_name(PCMK__FAIL_COUNT_PREFIX, rsc_id, op, interval_ms); } static inline char * pcmk__lastfailure_name(const char *rsc_id, const char *op, guint interval_ms) { return pcmk__fail_attr_name(PCMK__LAST_FAILURE_PREFIX, rsc_id, op, interval_ms); } // internal resource agent functions (from agents.c) int pcmk__effective_rc(int rc); #ifdef __cplusplus } #endif #endif // PCMK__CRM_COMMON_INTERNAL__H diff --git a/lib/common/io.c b/lib/common/io.c index 102d7f1bf0..972b927888 100644 --- a/lib/common/io.c +++ b/lib/common/io.c @@ -1,639 +1,635 @@ /* * Copyright 2004-2024 the Pacemaker project contributors * * The version control history for this file may have further details. * * This source code is licensed under the GNU Lesser General Public License * version 2.1 or later (LGPLv2.1+) WITHOUT ANY WARRANTY. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /*! * \internal * \brief Create a directory, including any parent directories needed * * \param[in] path_c Pathname of the directory to create * \param[in] mode Permissions to be used (with current umask) when creating * * \return Standard Pacemaker return code */ int pcmk__build_path(const char *path_c, mode_t mode) { int offset = 1, len = 0; int rc = pcmk_rc_ok; char *path = strdup(path_c); // cppcheck seems not to understand the abort logic in CRM_CHECK // cppcheck-suppress memleak CRM_CHECK(path != NULL, return -ENOMEM); for (len = strlen(path); offset < len; offset++) { if (path[offset] == '/') { path[offset] = 0; if ((mkdir(path, mode) < 0) && (errno != EEXIST)) { rc = errno; goto done; } path[offset] = '/'; } } if ((mkdir(path, mode) < 0) && (errno != EEXIST)) { rc = errno; } done: free(path); return rc; } /*! * \internal * \brief Return canonicalized form of a path name * * \param[in] path Pathname to canonicalize * \param[out] resolved_path Where to store canonicalized pathname * * \return Standard Pacemaker return code * \note The caller is responsible for freeing \p resolved_path on success. * \note This function exists because not all C library versions of * realpath(path, resolved_path) support a NULL resolved_path. */ int pcmk__real_path(const char *path, char **resolved_path) { CRM_CHECK((path != NULL) && (resolved_path != NULL), return EINVAL); #if _POSIX_VERSION >= 200809L /* Recent C libraries can dynamically allocate memory as needed */ *resolved_path = realpath(path, NULL); return (*resolved_path == NULL)? errno : pcmk_rc_ok; #elif defined(PATH_MAX) /* Older implementations require pre-allocated memory */ /* (this is less desirable because PATH_MAX may be huge or not defined) */ *resolved_path = malloc(PATH_MAX); if ((*resolved_path == NULL) || (realpath(path, *resolved_path) == NULL)) { return errno; } return pcmk_rc_ok; #else *resolved_path = NULL; return ENOTSUP; #endif } /*! * \internal * \brief Create a file name using a sequence number * * \param[in] directory Directory that contains the file series * \param[in] series Start of file name * \param[in] sequence Sequence number * \param[in] bzip Whether to use ".bz2" instead of ".raw" as extension * * \return Newly allocated file path (asserts on error, so always non-NULL) * \note The caller is responsible for freeing the return value. */ char * pcmk__series_filename(const char *directory, const char *series, unsigned int sequence, bool bzip) { pcmk__assert((directory != NULL) && (series != NULL)); return crm_strdup_printf("%s/%s-%u.%s", directory, series, sequence, (bzip? "bz2" : "raw")); } /*! * \internal * \brief Read sequence number stored in a file series' .last file * * \param[in] directory Directory that contains the file series * \param[in] series Start of file name * \param[out] seq Where to store the sequence number * * \return Standard Pacemaker return code */ int pcmk__read_series_sequence(const char *directory, const char *series, unsigned int *seq) { int rc; FILE *fp = NULL; char *series_file = NULL; if ((directory == NULL) || (series == NULL) || (seq == NULL)) { return EINVAL; } series_file = crm_strdup_printf("%s/%s.last", directory, series); fp = fopen(series_file, "r"); if (fp == NULL) { rc = errno; crm_debug("Could not open series file %s: %s", series_file, strerror(rc)); free(series_file); return rc; } errno = 0; if (fscanf(fp, "%u", seq) != 1) { rc = (errno == 0)? ENODATA : errno; crm_debug("Could not read sequence number from series file %s: %s", series_file, pcmk_rc_str(rc)); fclose(fp); return rc; } fclose(fp); crm_trace("Found last sequence number %u in series file %s", *seq, series_file); free(series_file); return pcmk_rc_ok; } /*! * \internal * \brief Write sequence number to a file series' .last file * * \param[in] directory Directory that contains the file series * \param[in] series Start of file name * \param[in] sequence Sequence number to write * \param[in] max Maximum sequence value, after which it is reset to 0 * * \note This function logs some errors but does not return any to the caller */ void pcmk__write_series_sequence(const char *directory, const char *series, unsigned int sequence, int max) { int rc = 0; FILE *file_strm = NULL; char *series_file = NULL; CRM_CHECK(directory != NULL, return); CRM_CHECK(series != NULL, return); if (max == 0) { return; } if (max > 0 && sequence >= max) { sequence = 0; } series_file = crm_strdup_printf("%s/%s.last", directory, series); file_strm = fopen(series_file, "w"); if (file_strm != NULL) { rc = fprintf(file_strm, "%u", sequence); if (rc < 0) { crm_perror(LOG_ERR, "Cannot write to series file %s", series_file); } } else { crm_err("Cannot open series file %s for writing", series_file); } if (file_strm != NULL) { fflush(file_strm); fclose(file_strm); } crm_trace("Wrote %d to %s", sequence, series_file); free(series_file); } /*! * \internal * \brief Change the owner and group of a file series' .last file * * \param[in] directory Directory that contains series * \param[in] series Series to change * \param[in] uid User ID of desired file owner * \param[in] gid Group ID of desired file group * * \return Standard Pacemaker return code * \note The caller must have the appropriate privileges. */ int pcmk__chown_series_sequence(const char *directory, const char *series, uid_t uid, gid_t gid) { char *series_file = NULL; int rc = pcmk_rc_ok; if ((directory == NULL) || (series == NULL)) { return EINVAL; } series_file = crm_strdup_printf("%s/%s.last", directory, series); if (chown(series_file, uid, gid) < 0) { rc = errno; } free(series_file); return rc; } static bool pcmk__daemon_user_can_write(const char *target_name, struct stat *target_stat) { struct passwd *sys_user = NULL; errno = 0; sys_user = getpwnam(CRM_DAEMON_USER); if (sys_user == NULL) { crm_notice("Could not find user %s: %s", CRM_DAEMON_USER, pcmk_rc_str(errno)); return FALSE; } if (target_stat->st_uid != sys_user->pw_uid) { crm_notice("%s is not owned by user %s " QB_XS " uid %d != %d", target_name, CRM_DAEMON_USER, sys_user->pw_uid, target_stat->st_uid); return FALSE; } if ((target_stat->st_mode & (S_IRUSR | S_IWUSR)) == 0) { crm_notice("%s is not readable and writable by user %s " QB_XS " st_mode=0%lo", target_name, CRM_DAEMON_USER, (unsigned long) target_stat->st_mode); return FALSE; } return TRUE; } static bool pcmk__daemon_group_can_write(const char *target_name, struct stat *target_stat) { struct group *sys_grp = NULL; errno = 0; sys_grp = getgrnam(CRM_DAEMON_GROUP); if (sys_grp == NULL) { crm_notice("Could not find group %s: %s", CRM_DAEMON_GROUP, pcmk_rc_str(errno)); return FALSE; } if (target_stat->st_gid != sys_grp->gr_gid) { crm_notice("%s is not owned by group %s " QB_XS " uid %d != %d", target_name, CRM_DAEMON_GROUP, sys_grp->gr_gid, target_stat->st_gid); return FALSE; } if ((target_stat->st_mode & (S_IRGRP | S_IWGRP)) == 0) { crm_notice("%s is not readable and writable by group %s " QB_XS " st_mode=0%lo", target_name, CRM_DAEMON_GROUP, (unsigned long) target_stat->st_mode); return FALSE; } return TRUE; } /*! * \internal * \brief Check whether a directory or file is writable by the cluster daemon * * Return true if either the cluster daemon user or cluster daemon group has * write permission on a specified file or directory. * * \param[in] dir Directory to check (this argument must be specified, and * the directory must exist) * \param[in] file File to check (only the directory will be checked if this * argument is not specified or the file does not exist) * * \return true if target is writable by cluster daemon, false otherwise */ bool pcmk__daemon_can_write(const char *dir, const char *file) { int s_res = 0; struct stat buf; char *full_file = NULL; const char *target = NULL; // Caller must supply directory pcmk__assert(dir != NULL); // If file is given, check whether it exists as a regular file if (file != NULL) { full_file = crm_strdup_printf("%s/%s", dir, file); target = full_file; s_res = stat(full_file, &buf); if (s_res < 0) { crm_notice("%s not found: %s", target, pcmk_rc_str(errno)); free(full_file); full_file = NULL; target = NULL; } else if (S_ISREG(buf.st_mode) == FALSE) { crm_err("%s must be a regular file " QB_XS " st_mode=0%lo", target, (unsigned long) buf.st_mode); free(full_file); return false; } } // If file is not given, ensure dir exists as directory if (target == NULL) { target = dir; s_res = stat(dir, &buf); if (s_res < 0) { crm_err("%s not found: %s", dir, pcmk_rc_str(errno)); return false; } else if (S_ISDIR(buf.st_mode) == FALSE) { crm_err("%s must be a directory " QB_XS " st_mode=0%lo", dir, (unsigned long) buf.st_mode); return false; } } if (!pcmk__daemon_user_can_write(target, &buf) && !pcmk__daemon_group_can_write(target, &buf)) { crm_err("%s must be owned and writable by either user %s or group %s " QB_XS " st_mode=0%lo", target, CRM_DAEMON_USER, CRM_DAEMON_GROUP, (unsigned long) buf.st_mode); free(full_file); return false; } free(full_file); return true; } /*! * \internal * \brief Flush and sync a directory to disk * * \param[in] name Directory to flush and sync * \note This function logs errors but does not return them to the caller */ void pcmk__sync_directory(const char *name) { int fd; DIR *directory; directory = opendir(name); if (directory == NULL) { crm_perror(LOG_ERR, "Could not open %s for syncing", name); return; } fd = dirfd(directory); if (fd < 0) { crm_perror(LOG_ERR, "Could not obtain file descriptor for %s", name); return; } if (fsync(fd) < 0) { crm_perror(LOG_ERR, "Could not sync %s", name); } if (closedir(directory) < 0) { crm_perror(LOG_ERR, "Could not close %s after fsync", name); } } /*! * \internal * \brief Read the contents of a file * * \param[in] filename Name of file to read * \param[out] contents Where to store file contents * * \return Standard Pacemaker return code * \note On success, the caller is responsible for freeing contents. */ int pcmk__file_contents(const char *filename, char **contents) { FILE *fp; int length, read_len; int rc = pcmk_rc_ok; if ((filename == NULL) || (contents == NULL)) { return EINVAL; } fp = fopen(filename, "r"); if ((fp == NULL) || (fseek(fp, 0L, SEEK_END) < 0)) { rc = errno; goto bail; } length = ftell(fp); if (length < 0) { rc = errno; goto bail; } if (length == 0) { *contents = NULL; } else { *contents = calloc(length + 1, sizeof(char)); if (*contents == NULL) { rc = errno; goto bail; } rewind(fp); read_len = fread(*contents, 1, length, fp); if (read_len != length) { free(*contents); *contents = NULL; rc = EIO; } else { /* Coverity thinks *contents isn't null-terminated. It doesn't * understand calloc(). */ (*contents)[length] = '\0'; } } bail: if (fp != NULL) { fclose(fp); } return rc; } /*! * \internal * \brief Write text to a file, flush and sync it to disk, then close the file * * \param[in] fd File descriptor opened for writing * \param[in] contents String to write to file * * \return Standard Pacemaker return code */ int pcmk__write_sync(int fd, const char *contents) { int rc = 0; FILE *fp = fdopen(fd, "w"); if (fp == NULL) { return errno; } if ((contents != NULL) && (fprintf(fp, "%s", contents) < 0)) { rc = EIO; } if (fflush(fp) != 0) { rc = errno; } if (fsync(fileno(fp)) < 0) { rc = errno; } fclose(fp); return rc; } /*! * \internal * \brief Set a file descriptor to non-blocking * * \param[in] fd File descriptor to use * * \return Standard Pacemaker return code */ int pcmk__set_nonblocking(int fd) { int flag = fcntl(fd, F_GETFL); if (flag < 0) { return errno; } if (fcntl(fd, F_SETFL, flag | O_NONBLOCK) < 0) { return errno; } return pcmk_rc_ok; } /*! * \internal * \brief Get directory name for temporary files * * Return the value of the TMPDIR environment variable if it is set to a * full path, otherwise return "/tmp". * * \return Name of directory to be used for temporary files */ const char * pcmk__get_tmpdir(void) { const char *dir = getenv("TMPDIR"); return (dir && (*dir == '/'))? dir : "/tmp"; } /*! * \internal * \brief Close open file descriptors * * Close all file descriptors (except optionally stdin, stdout, and stderr), * which is a best practice for a new child process forked for the purpose of * executing an external program. * * \param[in] bool If true, close stdin, stdout, and stderr as well */ void pcmk__close_fds_in_child(bool all) { DIR *dir; struct rlimit rlim; rlim_t max_fd; int min_fd = (all? 0 : (STDERR_FILENO + 1)); /* Find the current process's (soft) limit for open files. getrlimit() * should always work, but have a fallback just in case. */ if (getrlimit(RLIMIT_NOFILE, &rlim) == 0) { max_fd = rlim.rlim_cur - 1; } else { long conf_max = sysconf(_SC_OPEN_MAX); max_fd = (conf_max > 0)? conf_max : 1024; } - /* /proc/self/fd (on Linux) or /dev/fd (on most OSes) contains symlinks to - * all open files for the current process, named as the file descriptor. - * Use this if available, because it's more efficient than a shotgun - * approach to closing descriptors. + /* First try /proc. If that returns NULL (either because opening the + * directory failed, or because procfs isn't supported on this platform), + * fall back to /dev/fd. */ -#if HAVE_LINUX_PROCFS - dir = opendir("/proc/self/fd"); + dir = pcmk__procfs_fd_dir(); if (dir == NULL) { dir = opendir("/dev/fd"); } -#else - dir = opendir("/dev/fd"); -#endif // HAVE_LINUX_PROCFS + if (dir != NULL) { struct dirent *entry; int dir_fd = dirfd(dir); while ((entry = readdir(dir)) != NULL) { int lpc = atoi(entry->d_name); /* How could one of these entries be higher than max_fd, you ask? * It isn't possible in normal operation, but when run under * valgrind, valgrind can open high-numbered file descriptors for * its own use that are higher than the process's soft limit. * These will show up in the fd directory but aren't closable. */ if ((lpc >= min_fd) && (lpc <= max_fd) && (lpc != dir_fd)) { close(lpc); } } closedir(dir); return; } /* If no fd directory is available, iterate over all possible descriptors. * This is less efficient due to the overhead of many system calls. */ for (int lpc = max_fd; lpc >= min_fd; lpc--) { close(lpc); } } /*! * \brief Duplicate a file path, inserting a prefix if not absolute * * \param[in] filename File path to duplicate * \param[in] dirname If filename is not absolute, prefix to add * * \return Newly allocated memory with full path (guaranteed non-NULL) */ char * pcmk__full_path(const char *filename, const char *dirname) { pcmk__assert(filename != NULL); if (filename[0] == '/') { return pcmk__str_copy(filename); } pcmk__assert(dirname != NULL); return crm_strdup_printf("%s/%s", dirname, filename); } diff --git a/lib/common/procfs.c b/lib/common/procfs.c index 91853aafe7..92738a9beb 100644 --- a/lib/common/procfs.c +++ b/lib/common/procfs.c @@ -1,255 +1,277 @@ /* * Copyright 2015-2024 the Pacemaker project contributors * * The version control history for this file may have further details. * * This source code is licensed under the GNU Lesser General Public License * version 2.1 or later (LGPLv2.1+) WITHOUT ANY WARRANTY. */ #include #include #include #include #include #include #include #include #if HAVE_LINUX_PROCFS /*! * \internal * \brief Get process ID and name associated with a /proc directory entry * * \param[in] entry Directory entry (must be result of readdir() on /proc) * \param[out] name If not NULL, a char[16] to hold the process name * \param[out] pid If not NULL, will be set to process ID of entry * * \return Standard Pacemaker return code * \note This should be called only on Linux systems, as not all systems that * support /proc store process names and IDs in the same way. The kernel * limits the process name to the first 15 characters (plus terminator). * It would be nice if there were a public kernel API constant for that * limit, but there isn't. */ static int pcmk__procfs_process_info(const struct dirent *entry, char *name, pid_t *pid) { int fd, local_pid; FILE *file; struct stat statbuf; char procpath[128] = { 0 }; /* We're only interested in entries whose name is a PID, * so skip anything non-numeric or that is too long. * * 114 = 128 - strlen("/proc/") - strlen("/status") - 1 */ local_pid = atoi(entry->d_name); if ((local_pid <= 0) || (strlen(entry->d_name) > 114)) { return -1; } if (pid) { *pid = (pid_t) local_pid; } /* Get this entry's file information */ strcpy(procpath, "/proc/"); strcat(procpath, entry->d_name); fd = open(procpath, O_RDONLY); if (fd < 0 ) { return -1; } if (fstat(fd, &statbuf) < 0) { close(fd); return -1; } close(fd); /* We're only interested in subdirectories */ if (!S_ISDIR(statbuf.st_mode)) { return -1; } /* Read the first entry ("Name:") from the process's status file. * We could handle the valgrind case if we parsed the cmdline file * instead, but that's more of a pain than it's worth. */ if (name != NULL) { strcat(procpath, "/status"); file = fopen(procpath, "r"); if (!file) { return -1; } if (fscanf(file, "Name:\t%15[^\n]", name) != 1) { fclose(file); return -1; } name[15] = 0; fclose(file); } return 0; } #endif // HAVE_LINUX_PROCFS /*! * \internal * \brief Return process ID of a named process * * \param[in] name Process name (as used in /proc/.../status) * * \return Process ID of named process if running, 0 otherwise * * \note This will return 0 if the process is being run via valgrind. * This should be called only on Linux systems. */ pid_t pcmk__procfs_pid_of(const char *name) { #if HAVE_LINUX_PROCFS DIR *dp; struct dirent *entry; pid_t pid = 0; char entry_name[64] = { 0 }; dp = opendir("/proc"); if (dp == NULL) { crm_notice("Can not read /proc directory to track existing components"); return 0; } while ((entry = readdir(dp)) != NULL) { if ((pcmk__procfs_process_info(entry, entry_name, &pid) == pcmk_rc_ok) && pcmk__str_eq(entry_name, name, pcmk__str_casei) && (pcmk__pid_active(pid, NULL) == pcmk_rc_ok)) { crm_info("Found %s active as process %lld", name, (long long) pid); break; } pid = 0; } closedir(dp); return pid; #else return 0; #endif // HAVE_LINUX_PROCFS } /*! * \internal * \brief Calculate number of logical CPU cores from procfs * * \return Number of cores (or 1 if unable to determine) */ unsigned int pcmk__procfs_num_cores(void) { #if HAVE_LINUX_PROCFS int cores = 0; FILE *stream = NULL; /* Parse /proc/stat instead of /proc/cpuinfo because it's smaller */ stream = fopen("/proc/stat", "r"); if (stream == NULL) { crm_perror(LOG_INFO, "Could not open /proc/stat"); } else { char buffer[2048]; while (fgets(buffer, sizeof(buffer), stream)) { if (pcmk__starts_with(buffer, "cpu") && isdigit(buffer[3])) { ++cores; } } fclose(stream); } return cores? cores : 1; #else return 1; #endif // HAVE_LINUX_PROCFS } /*! * \internal * \brief Get the executable path corresponding to a process ID * * \param[in] pid Process ID to check * \param[out] path Where to store executable path * \param[in] path_size Size of \p path in characters (ideally PATH_MAX) * * \return Standard Pacemaker error code (as possible errno values from * readlink()) */ int pcmk__procfs_pid2path(pid_t pid, char path[], size_t path_size) { #if HAVE_LINUX_PROCFS char procfs_exe_path[PATH_MAX]; ssize_t link_rc; if (snprintf(procfs_exe_path, PATH_MAX, "/proc/%lld/exe", (long long) pid) >= PATH_MAX) { return ENAMETOOLONG; // Truncated (shouldn't be possible in practice) } link_rc = readlink(procfs_exe_path, path, path_size - 1); if (link_rc < 0) { return errno; } else if (link_rc >= (path_size - 1)) { return ENAMETOOLONG; } path[link_rc] = '\0'; return pcmk_rc_ok; #else return EOPNOTSUPP; #endif // HAVE_LINUX_PROCFS } /*! * \internal * \brief Check whether process ID information is available from procfs * * \return true if process ID information is available, otherwise false */ bool pcmk__procfs_has_pids(void) { #if HAVE_LINUX_PROCFS static bool have_pids = false; static bool checked = false; if (!checked) { char path[PATH_MAX]; have_pids = pcmk__procfs_pid2path(getpid(), path, sizeof(path)) == pcmk_rc_ok; checked = true; } return have_pids; #else return false; #endif // HAVE_LINUX_PROCFS } +/*! + * \internal + * \brief Return an open handle on the directory containing links to open file + * descriptors, or NULL on error + */ +DIR * +pcmk__procfs_fd_dir(void) +{ + DIR *dir = NULL; + + /* /proc/self/fd (on Linux) or /dev/fd (on most OSes) contains symlinks to + * all open files for the current process, named as the file descriptor. + * Use this if available, because it's more efficient than a shotgun + * approach to closing descriptors. + */ +#if HAVE_LINUX_PROCFS + dir = opendir("/proc/self/fd"); +#endif // HAVE_LINUX_PROCFS + + return dir; +} + /*! * \internal * \brief Trigger a sysrq command if supported on current platform * * \param[in] t Sysrq command to trigger */ void pcmk__sysrq_trigger(char t) { #if HAVE_LINUX_PROCFS // Root can always write here, regardless of kernel.sysrq value FILE *procf = fopen("/proc/sysrq-trigger", "a"); if (procf == NULL) { crm_warn("Could not open sysrq-trigger: %s", strerror(errno)); } else { fprintf(procf, "%c\n", t); fclose(procf); } #endif // HAVE_LINUX_PROCFS }