/*
	 * Copyright 2004-2026 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 <crm_internal.h>
	
	#include <dirent.h>
	#include <errno.h>
	#include <fcntl.h>
	#include <limits.h>
	#include <stdbool.h>            // bool, true, false
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <sys/param.h>
	#include <sys/resource.h>
	#include <sys/stat.h>
	#include <sys/types.h>
	#include <unistd.h>
	
	#include <crm/crm.h>
	#include <crm/common/util.h>
	
	/*!
	 * \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);
	
	    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 pcmk__assert_asprintf("%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 = pcmk__assert_asprintf("%s/%s.last", directory, series);
	    fp = fopen(series_file, "r");
	    if (fp == NULL) {
	        rc = errno;
	        pcmk__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;
	        pcmk__debug("Could not read sequence number from series file %s: %s",
	                    series_file, pcmk_rc_str(rc));
	        fclose(fp);
	        free(series_file);
	        return rc;
	    }
	    fclose(fp);
	    pcmk__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)
	{
	    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 = pcmk__assert_asprintf("%s/%s.last", directory, series);
	    file_strm = fopen(series_file, "w");
	    if (file_strm != NULL) {
	        int rc = fprintf(file_strm, "%u", sequence);
	
	        if (rc < 0) {
	            pcmk__err("Cannot write to series file %s", series_file);
	        }
	        fflush(file_strm);
	        fclose(file_strm);
	
	    } else {
	        pcmk__err("Cannot open series file %s for writing", 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 = pcmk__assert_asprintf("%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)
	{
	    uid_t daemon_uid = 0;
	    int rc = pcmk__daemon_user(&daemon_uid, NULL);
	
	    if (rc != pcmk_rc_ok) {
	        pcmk__notice("Could not find user " CRM_DAEMON_USER ": %s",
	                     pcmk_rc_str(rc));
	        return false;
	    }
	    if (target_stat->st_uid != daemon_uid) {
	        pcmk__notice("%s is not owned by user " CRM_DAEMON_USER " "
	                     QB_XS " uid %lld != %lld",
	                     target_name, (long long) daemon_uid,
	                     (long long) target_stat->st_uid);
	        return false;
	    }
	    if ((target_stat->st_mode & (S_IRUSR | S_IWUSR)) == 0) {
	        pcmk__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)
	{
	    gid_t daemon_gid = 0;
	    int rc = pcmk__daemon_user(NULL, &daemon_gid);
	
	    if (rc != pcmk_rc_ok) {
	        pcmk__notice("Could not find group " CRM_DAEMON_GROUP ": %s",
	                     pcmk_rc_str(rc));
	        return false;
	    }
	
	    if (target_stat->st_gid != daemon_gid) {
	        pcmk__notice("%s is not owned by group " CRM_DAEMON_GROUP " "
	                     QB_XS " gid %lld != %lld",
	                     target_name, (long long) daemon_gid,
	                     (long long) target_stat->st_gid);
	        return false;
	    }
	
	    if ((target_stat->st_mode & (S_IRGRP | S_IWGRP)) == 0) {
	        pcmk__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 = pcmk__assert_asprintf("%s/%s", dir, file);
	        target = full_file;
	
	        s_res = stat(full_file, &buf);

	        if (s_res < 0) {
	            pcmk__notice("%s not found: %s", target, pcmk_rc_str(errno));

	            g_clear_pointer(&full_file, &free);
	            target = NULL;
	
	        } else if (!S_ISREG(buf.st_mode)) {
	            pcmk__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) {
	            pcmk__err("%s not found: %s", dir, pcmk_rc_str(errno));
	            return false;
	
	        } else if (!S_ISDIR(buf.st_mode)) {
	            pcmk__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)) {
	
	        pcmk__err("%s must be owned and writable by either user "
	                  CRM_DAEMON_USER " or group " CRM_DAEMON_GROUP " "
	                  QB_XS " st_mode=0%lo",
	                  target, (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) {
	        pcmk__err("Could not open %s for syncing: %s", name, strerror(errno));
	        return;
	    }
	
	    fd = dirfd(directory);
	    if (fd < 0) {
	        pcmk__err("Could not obtain file descriptor for %s: %s", name,
	                  strerror(errno));
	        return;
	    }
	
	    if (fsync(fd) < 0) {
	        pcmk__err("Could not sync %s: %s", name, strerror(errno));
	    }
	    if (closedir(directory) < 0) {
	        pcmk__err("Could not close %s after fsync: %s", name, strerror(errno));
	    }
	}
	
	/*!
	 * \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;
	        }
	
	        errno = 0;
	
	        rewind(fp);
	        if (errno != 0) {
	            rc = errno;
	            goto bail;
	        }
	
	        read_len = fread(*contents, 1, length, fp);
	        if (read_len != length) {
	            g_clear_pointer(contents, &free);
	            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 except standard streams
	 *
	 * Close all file descriptors (except stdin, stdout, and stderr), which is a
	 * best practice for a new child process forked for the purpose of executing an
	 * external program.
	 */
	void
	pcmk__close_fds_in_child(void)
	{
	    DIR *dir;
	    struct rlimit rlim;
	    rlim_t max_fd;
	    const int min_fd = 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;
	    }
	
	    /* 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.
	     */
	    dir = pcmk__procfs_fd_dir();
	    if (dir == NULL) {
	        dir = opendir("/dev/fd");
	    }
	
	    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 pcmk__assert_asprintf("%s/%s", dirname, filename);
	}