X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Futils.c;h=57add319ba416b6eda1cb967fc126c008177f45f;hp=d0f050c0ff14d12e79f4f36d2e7adddb807e341d;hb=5154230f59b7f66abe33166cf14ef49d2c4e2219;hpb=00a52467faf94a4f07cfcc2fe3c9590d9cff3872 diff --git a/src/common/utils.c b/src/common/utils.c index d0f050c0f..57add319b 100644 --- a/src/common/utils.c +++ b/src/common/utils.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include @@ -34,6 +35,202 @@ #include "utils.h" #include "defaults.h" +/* + * 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_partial_realpath(const char *path, char *resolved_path, size_t size) +{ + char *cut_path, *try_path = NULL, *try_path_prev = NULL; + const char *next, *prev, *end; + + /* Safety net */ + if (path == NULL) { + goto error; + } + + /* + * 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 = strndup(path, next - path); + + /* 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); + }; + + /* 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; + } + } + + /* + * 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'; + } + + /* + * Duplicate the memory used by prev in case resolved_path and + * path are pointers for the same memory space + */ + cut_path = strdup(prev); + + /* 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); + /* + * 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); + return NULL; +} + +/* + * Resolve the './' and '../' strings in the middle of a path using + * our very own way to do it, so that it works even if the directory + * does not exist + */ +LTTNG_HIDDEN +char *utils_resolve_relative(const char *path) +{ + char *next, *previous, *slash, *start_path, *absolute_path = NULL; + + /* 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; + } + + /* Copy the path in the absolute path */ + strncpy(absolute_path, path, PATH_MAX); + + /* As long as we find '/./' in the path string */ + while ((next = strstr(absolute_path, "/./"))) { + + /* We prepare the start_path not containing it */ + start_path = strndup(absolute_path, next - absolute_path); + + /* And we concatenate it with the part after this string */ + snprintf(absolute_path, PATH_MAX, "%s%s", start_path, next + 2); + + free(start_path); + } + + /* As long as we find '/../' in the path string */ + while ((next = strstr(absolute_path, "/../"))) { + /* If the path starts with '/../', there's a problem */ + if (next == absolute_path) { + ERR("%s: Path cannot be resolved", path); + goto error; + } + + /* We find the last level of directory */ + previous = absolute_path; + while ((slash = strpbrk(previous + 1, "/")) && slash != next) { + previous = slash; + } + + /* Then we prepare the start_path not containing it */ + start_path = strndup(absolute_path, previous - absolute_path); + + /* And we concatenate it with the part after the '/../' */ + snprintf(absolute_path, PATH_MAX, "%s%s", start_path, next + 3); + + free(start_path); + } + + return absolute_path; + +error: + free(absolute_path); + return NULL; +} + + /* * 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 @@ -43,7 +240,7 @@ LTTNG_HIDDEN char *utils_expand_path(const char *path) { - const char *end_path = path; + const char *end_path = NULL; char *next, *cut_path = NULL, *expanded_path = NULL; /* Safety net */ @@ -51,38 +248,80 @@ char *utils_expand_path(const char *path) goto error; } - /* Find last token delimited by '/' */ - while ((next = strpbrk(end_path + 1, "/"))) { - end_path = next; - } - - /* Cut last token from original path */ - cut_path = strndup(path, end_path - path); - + /* Allocate memory for the expanded path */ expanded_path = zmalloc(PATH_MAX); if (expanded_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 given path is already absolute */ + if (*path == '/') { + strncpy(expanded_path, path, PATH_MAX); + /* Else, we have some work to do */ + } else { + /* Pointer to the last char of the path */ + const char *last_char = path + strlen(path) - 1; + + end_path = path; + + /* Split part that will be resolved by realpath (relative path from + * current directory using ./ or ../ only) and part that could not + * (directory names) + */ + while ((next = strpbrk(end_path, "/")) && (next != last_char)) { + end_path = next + 1; + if (strncmp(end_path, "./", 2) != 0 && + strncmp(end_path, "../", 3) != 0) { + break; + } + } + + /* If this is the end of the string, and we still can resolve it */ + if (strncmp(end_path, "..\0", 3) == 0 || + strncmp(end_path, ".\0", 2) == 0) { + end_path += strlen(end_path); + } + + /* If the end part is the whole path, we are in the current dir */ + if (end_path == path) { + cut_path = strdup("."); + /* Else, cut the resolvable part from original path */ + } else { + cut_path = strndup(path, end_path - path); + } + + /* Resolve the canonical path of the first part of the path */ + 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; + } + goto error; + } + + /* Add end part to expanded path if not empty */ + if (*end_path != 0) { + strncat(expanded_path, "/", PATH_MAX - strlen(expanded_path) - 1); + strncat(expanded_path, end_path, + PATH_MAX - strlen(expanded_path) - 1); } - goto error; } - /* Add end part to expanded path */ - strncat(expanded_path, end_path, PATH_MAX - strlen(expanded_path) - 1); + /* Resolve the internal './' and '../' strings */ + next = utils_resolve_relative(expanded_path); + if (next == NULL) { + goto error; + } + free(expanded_path); free(cut_path); - return expanded_path; + return next; error: free(expanded_path); @@ -142,6 +381,48 @@ 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. */ @@ -309,10 +590,11 @@ error: */ LTTNG_HIDDEN int utils_create_stream_file(const char *path_name, char *file_name, uint64_t size, - uint64_t count, int uid, int gid) + uint64_t count, int uid, int gid, char *suffix) { int ret, out_fd, flags, mode; - char full_path[PATH_MAX], *path_name_id = NULL, *path; + char full_path[PATH_MAX], *path_name_suffix = NULL, *path; + char *extra = NULL; assert(path_name); assert(file_name); @@ -324,17 +606,30 @@ int utils_create_stream_file(const char *path_name, char *file_name, uint64_t si 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 (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; + path = path_name_suffix; } else { path = full_path; } @@ -355,7 +650,9 @@ int utils_create_stream_file(const char *path_name, char *file_name, uint64_t si ret = out_fd; error_open: - free(path_name_id); + free(path_name_suffix); +error_free_suffix: + free(extra); error: return ret; } @@ -371,10 +668,14 @@ 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"); @@ -387,8 +688,16 @@ int utils_rotate_stream_file(char *path_name, char *file_name, uint64_t size, (*new_count)++; } - return utils_create_stream_file(path_name, file_name, size, *new_count, - uid, gid); + ret = utils_create_stream_file(path_name, file_name, size, *new_count, + uid, gid, 0); + if (ret < 0) { + goto error; + } + *stream_fd = ret; + + /* Success. */ + ret = 0; + error: return ret; } @@ -597,3 +906,51 @@ char *utils_get_home_dir(void) } return getenv(DEFAULT_LTTNG_FALLBACK_HOME_ENV_VAR); } + +/* + * 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 %lu", 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; +}