X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Futils.c;h=ca4eb44481c7d3e7fc90500c91112f50aaacef09;hp=f3718f00fa8ddabb7c921ac55287626dd83f45b8;hb=7a946bebe4a23b07f257906b90c88fed383835aa;hpb=70d0b120691e90d81de7b38af8b845e261b5b40c diff --git a/src/common/utils.c b/src/common/utils.c index f3718f00f..ca4eb4448 100644 --- a/src/common/utils.c +++ b/src/common/utils.c @@ -1,5 +1,7 @@ /* * Copyright (C) 2012 - David Goulet + * Copyright (C) 2013 - Raphaël Beamonte + * Copyright (C) 2013 - Jérémie Galarneau * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License, version 2 only, as @@ -16,76 +18,284 @@ */ #define _GNU_SOURCE +#define _LGPL_SOURCE #include #include #include #include #include -#include -#include #include +#include #include #include -#include +#include +#include +#include +#include #include #include +#include +#include #include "utils.h" +#include "defaults.h" /* - * Return the realpath(3) of the path even if the last directory token does not - * exist. For example, with /tmp/test1/test2, if test2/ does not exist but the - * /tmp/test1 does, the real path is returned. In normal time, realpath(3) - * fails if the end point directory does not exist. + * Return a partial realpath(3) of the path even if the full path does not + * exist. For instance, with /tmp/test1/test2/test3, if test2/ does not exist + * but the /tmp/test1 does, the real path for /tmp/test1 is concatened with + * /test2/test3 then returned. In normal time, realpath(3) fails if the end + * point directory does not exist. + * In case resolved_path is NULL, the string returned was allocated in the + * function and thus need to be freed by the caller. The size argument allows + * to specify the size of the resolved_path argument if given, or the size to + * allocate. */ LTTNG_HIDDEN -char *utils_expand_path(const char *path) +char *utils_partial_realpath(const char *path, char *resolved_path, size_t size) { - const char *end_path = path; - char *next, *cut_path = NULL, *expanded_path = NULL; + char *cut_path = NULL, *try_path = NULL, *try_path_prev = NULL; + const char *next, *prev, *end; /* Safety net */ if (path == NULL) { goto error; } - /* Find last token delimited by '/' */ - while ((next = strpbrk(end_path + 1, "/"))) { - end_path = next; + /* + * Identify the end of the path, we don't want to treat the + * last char if it is a '/', we will just keep it on the side + * to be added at the end, and return a value coherent with + * the path given as argument + */ + end = path + strlen(path); + if (*(end-1) == '/') { + end--; + } + + /* Initiate the values of the pointers before looping */ + next = path; + prev = next; + /* Only to ensure try_path is not NULL to enter the while */ + try_path = (char *)next; + + /* Resolve the canonical path of the first part of the path */ + while (try_path != NULL && next != end) { + /* + * If there is not any '/' left, we want to try with + * the full path + */ + next = strpbrk(next + 1, "/"); + if (next == NULL) { + next = end; + } + + /* Cut the part we will be trying to resolve */ + cut_path = lttng_strndup(path, next - path); + if (cut_path == NULL) { + PERROR("lttng_strndup"); + goto error; + } + + /* Try to resolve this part */ + try_path = realpath((char *)cut_path, NULL); + if (try_path == NULL) { + /* + * There was an error, we just want to be assured it + * is linked to an unexistent directory, if it's another + * reason, we spawn an error + */ + switch (errno) { + case ENOENT: + /* Ignore the error */ + break; + default: + PERROR("realpath (partial_realpath)"); + goto error; + break; + } + } else { + /* Save the place we are before trying the next step */ + free(try_path_prev); + try_path_prev = try_path; + prev = next; + } + + /* Free the allocated memory */ + free(cut_path); + cut_path = NULL; + } + + /* Allocate memory for the resolved path if necessary */ + if (resolved_path == NULL) { + resolved_path = zmalloc(size); + if (resolved_path == NULL) { + PERROR("zmalloc resolved path"); + goto error; + } } - /* Cut last token from original path */ - cut_path = strndup(path, end_path - path); + /* + * If we were able to solve at least partially the path, we can concatenate + * what worked and what didn't work + */ + if (try_path_prev != NULL) { + /* If we risk to concatenate two '/', we remove one of them */ + if (try_path_prev[strlen(try_path_prev) - 1] == '/' && prev[0] == '/') { + try_path_prev[strlen(try_path_prev) - 1] = '\0'; + } - expanded_path = zmalloc(PATH_MAX); - if (expanded_path == NULL) { + /* + * Duplicate the memory used by prev in case resolved_path and + * path are pointers for the same memory space + */ + cut_path = strdup(prev); + if (cut_path == NULL) { + PERROR("strdup"); + goto error; + } + + /* Concatenate the strings */ + snprintf(resolved_path, size, "%s%s", try_path_prev, cut_path); + + /* Free the allocated memory */ + free(cut_path); + free(try_path_prev); + cut_path = NULL; + try_path_prev = NULL; + /* + * Else, we just copy the path in our resolved_path to + * return it as is + */ + } else { + strncpy(resolved_path, path, size); + } + + /* Then we return the 'partially' resolved path */ + return resolved_path; + +error: + free(resolved_path); + free(cut_path); + return NULL; +} + +/* + * Make a full resolution of the given path even if it doesn't exist. + * This function uses the utils_partial_realpath function to resolve + * symlinks and relatives paths at the start of the string, and + * implements functionnalities to resolve the './' and '../' strings + * in the middle of a path. This function is only necessary because + * realpath(3) does not accept to resolve unexistent paths. + * The returned string was allocated in the function, it is thus of + * the responsibility of the caller to free this memory. + */ +LTTNG_HIDDEN +char *utils_expand_path(const char *path) +{ + char *next, *previous, *slash, *start_path, *absolute_path = NULL; + char *last_token; + int is_dot, is_dotdot; + + /* Safety net */ + if (path == NULL) { + goto error; + } + + /* Allocate memory for the absolute_path */ + absolute_path = zmalloc(PATH_MAX); + if (absolute_path == NULL) { PERROR("zmalloc expand path"); goto error; } - expanded_path = realpath((char *)cut_path, expanded_path); - if (expanded_path == NULL) { - switch (errno) { - case ENOENT: - ERR("%s: No such file or directory", cut_path); - break; - default: - PERROR("realpath utils expand path"); - break; + /* + * If the path is not already absolute nor explicitly relative, + * consider we're in the current directory + */ + if (*path != '/' && strncmp(path, "./", 2) != 0 && + strncmp(path, "../", 3) != 0) { + snprintf(absolute_path, PATH_MAX, "./%s", path); + /* Else, we just copy the path */ + } else { + strncpy(absolute_path, path, PATH_MAX); + } + + /* Resolve partially our path */ + absolute_path = utils_partial_realpath(absolute_path, + absolute_path, PATH_MAX); + + /* As long as we find '/./' in the working_path string */ + while ((next = strstr(absolute_path, "/./"))) { + + /* We prepare the start_path not containing it */ + start_path = lttng_strndup(absolute_path, next - absolute_path); + if (!start_path) { + PERROR("lttng_strndup"); + goto error; } - goto error; + /* And we concatenate it with the part after this string */ + snprintf(absolute_path, PATH_MAX, "%s%s", start_path, next + 2); + + free(start_path); } - /* Add end part to expanded path */ - strncat(expanded_path, end_path, PATH_MAX - strlen(expanded_path) - 1); + /* As long as we find '/../' in the working_path string */ + while ((next = strstr(absolute_path, "/../"))) { + /* We find the last level of directory */ + previous = absolute_path; + while ((slash = strpbrk(previous, "/")) && slash != next) { + previous = slash + 1; + } - free(cut_path); - return expanded_path; + /* Then we prepare the start_path not containing it */ + start_path = lttng_strndup(absolute_path, previous - absolute_path); + if (!start_path) { + PERROR("lttng_strndup"); + goto error; + } + + /* And we concatenate it with the part after the '/../' */ + snprintf(absolute_path, PATH_MAX, "%s%s", start_path, next + 4); + + /* We can free the memory used for the start path*/ + free(start_path); + + /* Then we verify for symlinks using partial_realpath */ + absolute_path = utils_partial_realpath(absolute_path, + absolute_path, PATH_MAX); + } + + /* Identify the last token */ + last_token = strrchr(absolute_path, '/'); + + /* Verify that this token is not a relative path */ + is_dotdot = (strcmp(last_token, "/..") == 0); + is_dot = (strcmp(last_token, "/.") == 0); + + /* If it is, take action */ + if (is_dot || is_dotdot) { + /* For both, remove this token */ + *last_token = '\0'; + + /* If it was a reference to parent directory, go back one more time */ + if (is_dotdot) { + last_token = strrchr(absolute_path, '/'); + + /* If there was only one level left, we keep the first '/' */ + if (last_token == absolute_path) { + last_token++; + } + + *last_token = '\0'; + } + } + + return absolute_path; error: - free(expanded_path); - free(cut_path); + free(absolute_path); return NULL; } @@ -141,6 +351,48 @@ error: return ret; } +/* + * Create pipe and set fd flags to FD_CLOEXEC and O_NONBLOCK. + * + * Make sure the pipe opened by this function are closed at some point. Use + * utils_close_pipe(). Using pipe() and fcntl rather than pipe2() to + * support OSes other than Linux 2.6.23+. + */ +LTTNG_HIDDEN +int utils_create_pipe_cloexec_nonblock(int *dst) +{ + int ret, i; + + if (dst == NULL) { + return -1; + } + + ret = utils_create_pipe(dst); + if (ret < 0) { + goto error; + } + + for (i = 0; i < 2; i++) { + ret = fcntl(dst[i], F_SETFD, FD_CLOEXEC); + if (ret < 0) { + PERROR("fcntl pipe cloexec"); + goto error; + } + /* + * Note: we override any flag that could have been + * previously set on the fd. + */ + ret = fcntl(dst[i], F_SETFL, O_NONBLOCK); + if (ret < 0) { + PERROR("fcntl pipe nonblock"); + goto error; + } + } + +error: + return ret; +} + /* * Close both read and write side of the pipe. */ @@ -231,24 +483,97 @@ int utils_create_pid_file(pid_t pid, const char *filepath) ret = fprintf(fp, "%d\n", pid); if (ret < 0) { PERROR("fprintf pid file"); + goto error; } - fclose(fp); + if (fclose(fp)) { + PERROR("fclose"); + } DBG("Pid %d written in file %s", pid, filepath); + ret = 0; error: return ret; } /* - * Recursively create directory using the given path and mode. + * Create lock file to the given path and filename. + * Returns the associated file descriptor, -1 on error. + */ +LTTNG_HIDDEN +int utils_create_lock_file(const char *filepath) +{ + int ret; + int fd; + + assert(filepath); + + fd = open(filepath, O_CREAT, + O_WRONLY | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP); + if (fd < 0) { + PERROR("open lock file %s", filepath); + ret = -1; + goto error; + } + + /* + * Attempt to lock the file. If this fails, there is + * already a process using the same lock file running + * and we should exit. + */ + ret = flock(fd, LOCK_EX | LOCK_NB); + if (ret) { + ERR("Could not get lock file %s, another instance is running.", + filepath); + if (close(fd)) { + PERROR("close lock file"); + } + fd = ret; + goto error; + } + +error: + return fd; +} + +/* + * Create directory using the given path and mode. * * On success, return 0 else a negative error code. */ LTTNG_HIDDEN -int utils_mkdir_recursive(const char *path, mode_t mode) +int utils_mkdir(const char *path, mode_t mode, int uid, int gid) +{ + int ret; + + if (uid < 0 || gid < 0) { + ret = mkdir(path, mode); + } else { + ret = run_as_mkdir(path, mode, uid, gid); + } + if (ret < 0) { + if (errno != EEXIST) { + PERROR("mkdir %s, uid %d, gid %d", path ? path : "NULL", + uid, gid); + } else { + ret = 0; + } + } + + return ret; +} + +/* + * Internal version of mkdir_recursive. Runs as the current user. + * Don't call directly; use utils_mkdir_recursive(). + * + * This function is ominously marked as "unsafe" since it should only + * be called by a caller that has transitioned to the uid and gid under which + * the directory creation should occur. + */ +LTTNG_HIDDEN +int _utils_mkdir_recursive_unsafe(const char *path, mode_t mode) { char *p, tmp[PATH_MAX]; - struct stat statbuf; size_t len; int ret; @@ -276,15 +601,12 @@ int utils_mkdir_recursive(const char *path, mode_t mode) ret = -1; goto error; } - ret = stat(tmp, &statbuf); + ret = mkdir(tmp, mode); if (ret < 0) { - ret = mkdir(tmp, mode); - if (ret < 0) { - if (errno != EEXIST) { - PERROR("mkdir recursive"); - ret = -errno; - goto error; - } + if (errno != EEXIST) { + PERROR("mkdir recursive"); + ret = -errno; + goto error; } } *p = '/'; @@ -294,7 +616,7 @@ int utils_mkdir_recursive(const char *path, mode_t mode) ret = mkdir(tmp, mode); if (ret < 0) { if (errno != EEXIST) { - PERROR("mkdir recursive last piece"); + PERROR("mkdir recursive last element"); ret = -errno; } else { ret = 0; @@ -306,19 +628,44 @@ error: } /* - * Create the stream tracefile on disk. + * Recursively create directory using the given path and mode, under the + * provided uid and gid. * - * Return 0 on success or else a negative value. + * On success, return 0 else a negative error code. */ LTTNG_HIDDEN -int utils_create_stream_file(char *path_name, char *file_name, uint64_t size, - uint64_t count, int uid, int gid) +int utils_mkdir_recursive(const char *path, mode_t mode, int uid, int gid) { - int ret, out_fd, flags, mode; - char full_path[PATH_MAX], *path_name_id = NULL, *path; + int ret; + + if (uid < 0 || gid < 0) { + /* Run as current user. */ + ret = _utils_mkdir_recursive_unsafe(path, mode); + } else { + ret = run_as_mkdir_recursive(path, mode, uid, gid); + } + if (ret < 0) { + PERROR("mkdir %s, uid %d, gid %d", path ? path : "NULL", + uid, gid); + } - assert(path_name); - assert(file_name); + return ret; +} + +/* + * path is the output parameter. It needs to be PATH_MAX len. + * + * Return 0 on success or else a negative value. + */ +static int utils_stream_file_name(char *path, + const char *path_name, const char *file_name, + uint64_t size, uint64_t count, + const char *suffix) +{ + int ret; + char full_path[PATH_MAX]; + char *path_name_suffix = NULL; + char *extra = NULL; ret = snprintf(full_path, sizeof(full_path), "%s/%s", path_name, file_name); @@ -327,19 +674,60 @@ int utils_create_stream_file(char *path_name, char *file_name, uint64_t size, goto error; } + /* Setup extra string if suffix or/and a count is needed. */ + if (size > 0 && suffix) { + ret = asprintf(&extra, "_%" PRIu64 "%s", count, suffix); + } else if (size > 0) { + ret = asprintf(&extra, "_%" PRIu64, count); + } else if (suffix) { + ret = asprintf(&extra, "%s", suffix); + } + if (ret < 0) { + PERROR("Allocating extra string to name"); + goto error; + } + /* - * If we split the trace in multiple files, we have to add the count at the - * end of the tracefile name + * If we split the trace in multiple files, we have to add the count at + * the end of the tracefile name. */ - if (size > 0) { - ret = asprintf(&path_name_id, "%s_%" PRIu64, full_path, count); + if (extra) { + ret = asprintf(&path_name_suffix, "%s%s", full_path, extra); if (ret < 0) { - PERROR("Allocating path name ID"); - goto error; + PERROR("Allocating path name with extra string"); + goto error_free_suffix; } - path = path_name_id; + strncpy(path, path_name_suffix, PATH_MAX - 1); + path[PATH_MAX - 1] = '\0'; } else { - path = full_path; + strncpy(path, full_path, PATH_MAX - 1); + } + path[PATH_MAX - 1] = '\0'; + ret = 0; + + free(path_name_suffix); +error_free_suffix: + free(extra); +error: + return ret; +} + +/* + * Create the stream file on disk. + * + * Return 0 on success or else a negative value. + */ +LTTNG_HIDDEN +int utils_create_stream_file(const char *path_name, char *file_name, uint64_t size, + uint64_t count, int uid, int gid, char *suffix) +{ + int ret, flags, mode; + char path[PATH_MAX]; + + ret = utils_stream_file_name(path, path_name, file_name, + size, count, suffix); + if (ret < 0) { + goto error; } flags = O_WRONLY | O_CREAT | O_TRUNC; @@ -347,19 +735,44 @@ int utils_create_stream_file(char *path_name, char *file_name, uint64_t size, mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP; if (uid < 0 || gid < 0) { - out_fd = open(path, flags, mode); + ret = open(path, flags, mode); } else { - out_fd = run_as_open(path, flags, mode, uid, gid); + ret = run_as_open(path, flags, mode, uid, gid); } - if (out_fd < 0) { + if (ret < 0) { PERROR("open stream path %s", path); - goto error_open; } - ret = out_fd; +error: + return ret; +} -error_open: - free(path_name_id); +/* + * Unlink the stream tracefile from disk. + * + * Return 0 on success or else a negative value. + */ +LTTNG_HIDDEN +int utils_unlink_stream_file(const char *path_name, char *file_name, uint64_t size, + uint64_t count, int uid, int gid, char *suffix) +{ + int ret; + char path[PATH_MAX]; + + ret = utils_stream_file_name(path, path_name, file_name, + size, count, suffix); + if (ret < 0) { + goto error; + } + if (uid < 0 || gid < 0) { + ret = unlink(path); + } else { + ret = run_as_unlink(path, uid, gid); + } + if (ret < 0) { + goto error; + } error: + DBG("utils_unlink_stream_file %s returns %d", path, ret); return ret; } @@ -374,10 +787,14 @@ error: */ LTTNG_HIDDEN int utils_rotate_stream_file(char *path_name, char *file_name, uint64_t size, - uint64_t count, int uid, int gid, int out_fd, uint64_t *new_count) + uint64_t count, int uid, int gid, int out_fd, uint64_t *new_count, + int *stream_fd) { int ret; + assert(new_count); + assert(stream_fd); + ret = close(out_fd); if (ret < 0) { PERROR("Closing tracefile"); @@ -385,53 +802,47 @@ int utils_rotate_stream_file(char *path_name, char *file_name, uint64_t size, } if (count > 0) { + /* + * In tracefile rotation, for the relay daemon we need + * to unlink the old file if present, because it may + * still be open in reading by the live thread, and we + * need to ensure that we do not overwrite the content + * between get_index and get_packet. Since we have no + * way to verify integrity of the data content compared + * to the associated index, we need to ensure the reader + * has exclusive access to the file content, and that + * the open of the data file is performed in get_index. + * Unlinking the old file rather than overwriting it + * achieves this. + */ *new_count = (*new_count + 1) % count; + ret = utils_unlink_stream_file(path_name, file_name, + size, *new_count, uid, gid, 0); + if (ret < 0 && errno != ENOENT) { + goto error; + } } else { (*new_count)++; } - return utils_create_stream_file(path_name, file_name, size, *new_count, - uid, gid); -error: - return ret; -} - -/** - * Prints the error message corresponding to a regex error code. - * - * @param errcode The error code. - * @param regex The regex object that produced the error code. - */ -static void regex_print_error(int errcode, regex_t *regex) -{ - /* Get length of error message and allocate accordingly */ - size_t length; - char *buffer; - - assert(regex != NULL); - - length = regerror(errcode, regex, NULL, 0); - if (length == 0) { - ERR("regerror returned a length of 0"); - return; - } - - buffer = zmalloc(length); - if (!buffer) { - ERR("regex_print_error: zmalloc failed"); - return; + ret = utils_create_stream_file(path_name, file_name, size, *new_count, + uid, gid, 0); + if (ret < 0) { + goto error; } + *stream_fd = ret; - /* Get and print error message */ - regerror(errcode, regex, buffer, length); - ERR("regex error: %s\n", buffer); - free(buffer); + /* Success. */ + ret = 0; +error: + return ret; } + /** * Parse a string that represents a size in human readable format. It - * supports decimal integers suffixed by 'k', 'M' or 'G'. + * supports decimal integers suffixed by 'k', 'K', 'M' or 'G'. * * The suffix multiply the integer by: * 'k': 1024 @@ -439,82 +850,423 @@ static void regex_print_error(int errcode, regex_t *regex) * 'G': 1024^3 * * @param str The string to parse. - * @param size Pointer to a size_t that will be filled with the - * resulting size. + * @param size Pointer to a uint64_t that will be filled with the + * resulting size. * * @return 0 on success, -1 on failure. */ -int utils_parse_size_suffix(char *str, uint64_t *size) +LTTNG_HIDDEN +int utils_parse_size_suffix(const char * const str, uint64_t * const size) { - regex_t regex; int ret; - const int nmatch = 3; - regmatch_t suffix_match, matches[nmatch]; - unsigned long long base_size; + uint64_t base_size; long shift = 0; + const char *str_end; + char *num_end; if (!str) { - return 0; - } - - /* Compile regex */ - ret = regcomp(®ex, "^\\(0x\\)\\{0,1\\}[0-9][0-9]*\\([kKMG]\\{0,1\\}\\)$", 0); - if (ret != 0) { - regex_print_error(ret, ®ex); + DBG("utils_parse_size_suffix: received a NULL string."); ret = -1; goto end; } - /* Match regex */ - ret = regexec(®ex, str, nmatch, matches, 0); - if (ret != 0) { + /* strtoull will accept a negative number, but we don't want to. */ + if (strchr(str, '-') != NULL) { + DBG("utils_parse_size_suffix: invalid size string, should not contain '-'."); ret = -1; - goto free; + goto end; } - /* There is a match ! */ + /* str_end will point to the \0 */ + str_end = str + strlen(str); errno = 0; - base_size = strtoull(str, NULL, 0); + base_size = strtoull(str, &num_end, 0); if (errno != 0) { - PERROR("strtoull"); + PERROR("utils_parse_size_suffix strtoull"); ret = -1; - goto free; + goto end; } - /* Check if there is a suffix */ - suffix_match = matches[2]; - if (suffix_match.rm_eo - suffix_match.rm_so == 1) { - switch (*(str + suffix_match.rm_so)) { - case 'K': - case 'k': - shift = KIBI_LOG2; - break; - case 'M': - shift = MEBI_LOG2; - break; - case 'G': - shift = GIBI_LOG2; - break; - default: - ERR("parse_human_size: invalid suffix"); - ret = -1; - goto free; - } + if (num_end == str) { + /* strtoull parsed nothing, not good. */ + DBG("utils_parse_size_suffix: strtoull had nothing good to parse."); + ret = -1; + goto end; + } + + /* Check if a prefix is present. */ + switch (*num_end) { + case 'G': + shift = GIBI_LOG2; + num_end++; + break; + case 'M': /* */ + shift = MEBI_LOG2; + num_end++; + break; + case 'K': + case 'k': + shift = KIBI_LOG2; + num_end++; + break; + case '\0': + break; + default: + DBG("utils_parse_size_suffix: invalid suffix."); + ret = -1; + goto end; + } + + /* Check for garbage after the valid input. */ + if (num_end != str_end) { + DBG("utils_parse_size_suffix: Garbage after size string."); + ret = -1; + goto end; } *size = base_size << shift; /* Check for overflow */ if ((*size >> shift) != base_size) { - ERR("parse_size_suffix: oops, overflow detected."); + DBG("utils_parse_size_suffix: oops, overflow detected."); ret = -1; - goto free; + goto end; } ret = 0; +end: + return ret; +} + +/* + * fls: returns the position of the most significant bit. + * Returns 0 if no bit is set, else returns the position of the most + * significant bit (from 1 to 32 on 32-bit, from 1 to 64 on 64-bit). + */ +#if defined(__i386) || defined(__x86_64) +static inline unsigned int fls_u32(uint32_t x) +{ + int r; + + asm("bsrl %1,%0\n\t" + "jnz 1f\n\t" + "movl $-1,%0\n\t" + "1:\n\t" + : "=r" (r) : "rm" (x)); + return r + 1; +} +#define HAS_FLS_U32 +#endif + +#ifndef HAS_FLS_U32 +static __attribute__((unused)) unsigned int fls_u32(uint32_t x) +{ + unsigned int r = 32; + + if (!x) { + return 0; + } + if (!(x & 0xFFFF0000U)) { + x <<= 16; + r -= 16; + } + if (!(x & 0xFF000000U)) { + x <<= 8; + r -= 8; + } + if (!(x & 0xF0000000U)) { + x <<= 4; + r -= 4; + } + if (!(x & 0xC0000000U)) { + x <<= 2; + r -= 2; + } + if (!(x & 0x80000000U)) { + x <<= 1; + r -= 1; + } + return r; +} +#endif + +/* + * Return the minimum order for which x <= (1UL << order). + * Return -1 if x is 0. + */ +LTTNG_HIDDEN +int utils_get_count_order_u32(uint32_t x) +{ + if (!x) { + return -1; + } + + return fls_u32(x - 1); +} + +/** + * Obtain the value of LTTNG_HOME environment variable, if exists. + * Otherwise returns the value of HOME. + */ +LTTNG_HIDDEN +char *utils_get_home_dir(void) +{ + char *val = NULL; + struct passwd *pwd; + + val = lttng_secure_getenv(DEFAULT_LTTNG_HOME_ENV_VAR); + if (val != NULL) { + goto end; + } + val = lttng_secure_getenv(DEFAULT_LTTNG_FALLBACK_HOME_ENV_VAR); + if (val != NULL) { + goto end; + } + + /* Fallback on the password file entry. */ + pwd = getpwuid(getuid()); + if (!pwd) { + goto end; + } + val = pwd->pw_dir; + + DBG3("Home directory is '%s'", val); -free: - regfree(®ex); end: + return val; +} + +/** + * Get user's home directory. Dynamically allocated, must be freed + * by the caller. + */ +LTTNG_HIDDEN +char *utils_get_user_home_dir(uid_t uid) +{ + struct passwd pwd; + struct passwd *result; + char *home_dir = NULL; + char *buf = NULL; + long buflen; + int ret; + + buflen = sysconf(_SC_GETPW_R_SIZE_MAX); + if (buflen == -1) { + goto end; + } +retry: + buf = zmalloc(buflen); + if (!buf) { + goto end; + } + + ret = getpwuid_r(uid, &pwd, buf, buflen, &result); + if (ret || !result) { + if (ret == ERANGE) { + free(buf); + buflen *= 2; + goto retry; + } + goto end; + } + + home_dir = strdup(pwd.pw_dir); +end: + free(buf); + return home_dir; +} + +/* + * Obtain the value of LTTNG_KMOD_PROBES environment variable, if exists. + * Otherwise returns NULL. + */ +LTTNG_HIDDEN +char *utils_get_kmod_probes_list(void) +{ + return lttng_secure_getenv(DEFAULT_LTTNG_KMOD_PROBES); +} + +/* + * Obtain the value of LTTNG_EXTRA_KMOD_PROBES environment variable, if + * exists. Otherwise returns NULL. + */ +LTTNG_HIDDEN +char *utils_get_extra_kmod_probes_list(void) +{ + return lttng_secure_getenv(DEFAULT_LTTNG_EXTRA_KMOD_PROBES); +} + +/* + * With the given format, fill dst with the time of len maximum siz. + * + * Return amount of bytes set in the buffer or else 0 on error. + */ +LTTNG_HIDDEN +size_t utils_get_current_time_str(const char *format, char *dst, size_t len) +{ + size_t ret; + time_t rawtime; + struct tm *timeinfo; + + assert(format); + assert(dst); + + /* Get date and time for session path */ + time(&rawtime); + timeinfo = localtime(&rawtime); + ret = strftime(dst, len, format, timeinfo); + if (ret == 0) { + ERR("Unable to strftime with format %s at dst %p of len %zu", format, + dst, len); + } + + return ret; +} + +/* + * Return the group ID matching name, else 0 if it cannot be found. + */ +LTTNG_HIDDEN +gid_t utils_get_group_id(const char *name) +{ + struct group *grp; + + grp = getgrnam(name); + if (!grp) { + static volatile int warn_once; + + if (!warn_once) { + WARN("No tracing group detected"); + warn_once = 1; + } + return 0; + } + return grp->gr_gid; +} + +/* + * Return a newly allocated option string. This string is to be used as the + * optstring argument of getopt_long(), see GETOPT(3). opt_count is the number + * of elements in the long_options array. Returns NULL if the string's + * allocation fails. + */ +LTTNG_HIDDEN +char *utils_generate_optstring(const struct option *long_options, + size_t opt_count) +{ + int i; + size_t string_len = opt_count, str_pos = 0; + char *optstring; + + /* + * Compute the necessary string length. One letter per option, two when an + * argument is necessary, and a trailing NULL. + */ + for (i = 0; i < opt_count; i++) { + string_len += long_options[i].has_arg ? 1 : 0; + } + + optstring = zmalloc(string_len); + if (!optstring) { + goto end; + } + + for (i = 0; i < opt_count; i++) { + if (!long_options[i].name) { + /* Got to the trailing NULL element */ + break; + } + + if (long_options[i].val != '\0') { + optstring[str_pos++] = (char) long_options[i].val; + if (long_options[i].has_arg) { + optstring[str_pos++] = ':'; + } + } + } + +end: + return optstring; +} + +/* + * Try to remove a hierarchy of empty directories, recursively. Don't unlink + * any file. Try to rmdir any empty directory within the hierarchy. + */ +LTTNG_HIDDEN +int utils_recursive_rmdir(const char *path) +{ + DIR *dir; + size_t path_len; + int dir_fd, ret = 0, closeret, is_empty = 1; + struct dirent *entry; + + /* Open directory */ + dir = opendir(path); + if (!dir) { + PERROR("Cannot open '%s' path", path); + return -1; + } + dir_fd = dirfd(dir); + if (dir_fd < 0) { + PERROR("dirfd"); + return -1; + } + + path_len = strlen(path); + while ((entry = readdir(dir))) { + if (!strcmp(entry->d_name, ".") + || !strcmp(entry->d_name, "..")) + continue; + + struct stat st; + size_t name_len; + char filename[PATH_MAX]; + + name_len = strlen(entry->d_name); + if (path_len + name_len + 2 > sizeof(filename)) { + ERR("Failed to remove file: path name too long (%s/%s)", + path, entry->d_name); + continue; + } + if (snprintf(filename, sizeof(filename), "%s/%s", + path, entry->d_name) < 0) { + ERR("Failed to format path."); + continue; + } + + if (stat(filename, &st)) { + PERROR("stat"); + continue; + } + + if (S_ISDIR(st.st_mode)) { + char subpath[PATH_MAX]; + + strncpy(subpath, path, PATH_MAX); + subpath[PATH_MAX - 1] = '\0'; + strncat(subpath, "/", + PATH_MAX - strlen(subpath) - 1); + strncat(subpath, entry->d_name, + PATH_MAX - strlen(subpath) - 1); + if (utils_recursive_rmdir(subpath)) { + is_empty = 0; + } + } else if (S_ISREG(st.st_mode)) { + is_empty = 0; + } else { + ret = -EINVAL; + goto end; + } + } +end: + closeret = closedir(dir); + if (closeret) { + PERROR("closedir"); + } + if (is_empty) { + DBG3("Attempting rmdir %s", path); + ret = rmdir(path); + } return ret; }