/*
* Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
+ * Copyright (C) 2013 - Raphaël Beamonte <raphael.beamonte@gmail.com>
+ * Copyright (C) 2013 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
*
* 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
* Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
-#define _GNU_SOURCE
+#define _LGPL_SOURCE
+#include <assert.h>
#include <ctype.h>
#include <fcntl.h>
#include <limits.h>
#include <stdlib.h>
-#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <inttypes.h>
+#include <grp.h>
+#include <pwd.h>
+#include <sys/file.h>
+#include <unistd.h>
#include <common/common.h>
+#include <common/runas.h>
+#include <common/compat/getenv.h>
+#include <common/compat/string.h>
+#include <common/compat/dirent.h>
+#include <lttng/constant.h>
#include "utils.h"
+#include "defaults.h"
+#include "time.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.
*/
-__attribute__((visibility("hidden")))
-char *utils_expand_path(const char *path)
+LTTNG_HIDDEN
+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--;
}
- /* Cut last token from original path */
- cut_path = strndup(path, end_path - path);
+ /* 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;
- expanded_path = zmalloc(PATH_MAX);
- if (expanded_path == NULL) {
- PERROR("zmalloc expand path");
+ /* Resolve the canonical path of the first part of the path */
+ while (try_path != NULL && next != end) {
+ char *try_path_buf = NULL;
+
+ /*
+ * 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_path_buf = zmalloc(LTTNG_PATH_MAX);
+ if (!try_path_buf) {
+ PERROR("zmalloc");
+ goto error;
+ }
+
+ /* Try to resolve this part */
+ try_path = realpath((char *) cut_path, try_path_buf);
+ if (try_path == NULL) {
+ free(try_path_buf);
+ /*
+ * 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 */
+ try_path_buf = NULL;
+ 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;
+ }
+ }
+
+ /*
+ * 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);
+ 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);
+ free(try_path);
+ if (try_path_prev != try_path) {
+ free(try_path_prev);
+ }
+ return NULL;
+}
+
+static
+int expand_double_slashes_dot_and_dotdot(char *path)
+{
+ size_t expanded_path_len, path_len;
+ const char *curr_char, *path_last_char, *next_slash, *prev_slash;
+
+ path_len = strlen(path);
+ path_last_char = &path[path_len];
+
+ if (path_len == 0) {
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);
+ expanded_path_len = 0;
+
+ /* We iterate over the provided path to expand the "//", "../" and "./" */
+ for (curr_char = path; curr_char <= path_last_char; curr_char = next_slash + 1) {
+ /* Find the next forward slash. */
+ size_t curr_token_len;
+
+ if (curr_char == path_last_char) {
+ expanded_path_len++;
+ break;
+ }
+
+ next_slash = memchr(curr_char, '/', path_last_char - curr_char);
+ if (next_slash == NULL) {
+ /* Reached the end of the provided path. */
+ next_slash = path_last_char;
+ }
+
+ /* Compute how long is the previous token. */
+ curr_token_len = next_slash - curr_char;
+ switch(curr_token_len) {
+ case 0:
+ /*
+ * The pointer has not move meaning that curr_char is
+ * pointing to a slash. It that case there is no token
+ * to copy, so continue the iteration to find the next
+ * token
+ */
+ continue;
+ case 1:
+ /*
+ * The pointer moved 1 character. Check if that
+ * character is a dot ('.'), if it is: omit it, else
+ * copy the token to the normalized path.
+ */
+ if (curr_char[0] == '.') {
+ continue;
+ }
+ break;
+ case 2:
+ /*
+ * The pointer moved 2 characters. Check if these
+ * characters are double dots ('..'). If that is the
+ * case, we need to remove the last token of the
+ * normalized path.
+ */
+ if (curr_char[0] == '.' && curr_char[1] == '.') {
+ /*
+ * Find the previous path component by
+ * using the memrchr function to find the
+ * previous forward slash and substract that
+ * len to the resulting path.
+ */
+ prev_slash = lttng_memrchr(path, '/', expanded_path_len);
+ /*
+ * If prev_slash is NULL, we reached the
+ * beginning of the path. We can't go back any
+ * further.
+ */
+ if (prev_slash != NULL) {
+ expanded_path_len = prev_slash - path;
+ }
+ continue;
+ }
break;
default:
- PERROR("realpath utils expand path");
break;
}
+
+ /*
+ * Copy the current token which is neither a '.' nor a '..'.
+ */
+ path[expanded_path_len++] = '/';
+ memcpy(&path[expanded_path_len], curr_char, curr_token_len);
+ expanded_path_len += curr_token_len;
+ }
+
+ if (expanded_path_len == 0) {
+ path[expanded_path_len++] = '/';
+ }
+
+ path[expanded_path_len] = '\0';
+ return 0;
+error:
+ return -1;
+}
+
+/*
+ * 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, bool keep_symlink)
+{
+ int ret;
+ char *absolute_path = NULL;
+ char *last_token;
+ bool is_dot, is_dotdot;
+
+ /* Safety net */
+ if (path == NULL) {
+ goto error;
+ }
+
+ /* Allocate memory for the absolute_path */
+ absolute_path = zmalloc(LTTNG_PATH_MAX);
+ if (absolute_path == NULL) {
+ PERROR("zmalloc expand path");
+ goto error;
+ }
+
+ if (path[0] == '/') {
+ ret = lttng_strncpy(absolute_path, path, LTTNG_PATH_MAX);
+ if (ret) {
+ ERR("Path exceeds maximal size of %i bytes", LTTNG_PATH_MAX);
+ goto error;
+ }
+ } else {
+ /*
+ * This is a relative path. We need to get the present working
+ * directory and start the path walk from there.
+ */
+ char current_working_dir[LTTNG_PATH_MAX];
+ char *cwd_ret;
+
+ cwd_ret = getcwd(current_working_dir, sizeof(current_working_dir));
+ if (!cwd_ret) {
+ goto error;
+ }
+ /*
+ * Get the number of character in the CWD and allocate an array
+ * to can hold it and the path provided by the caller.
+ */
+ ret = snprintf(absolute_path, LTTNG_PATH_MAX, "%s/%s",
+ current_working_dir, path);
+ if (ret >= LTTNG_PATH_MAX) {
+ ERR("Concatenating current working directory %s and path %s exceeds maximal size of %i bytes",
+ current_working_dir, path, LTTNG_PATH_MAX);
+ goto error;
+ }
+ }
+
+ if (keep_symlink) {
+ /* Resolve partially our path */
+ absolute_path = utils_partial_realpath(absolute_path,
+ absolute_path, LTTNG_PATH_MAX);
+ }
+
+ ret = expand_double_slashes_dot_and_dotdot(absolute_path);
+ if (ret) {
goto error;
}
- /* Add end part to expanded path */
- strncat(expanded_path, end_path, PATH_MAX - strlen(expanded_path) - 1);
+ /* Identify the last token */
+ last_token = strrchr(absolute_path, '/');
- free(cut_path);
- return expanded_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;
}
+LTTNG_HIDDEN
+char *utils_expand_path(const char *path)
+{
+ return _utils_expand_path(path, true);
+}
+LTTNG_HIDDEN
+char *utils_expand_path_keep_symlink(const char *path)
+{
+ return _utils_expand_path(path, false);
+}
/*
* Create a pipe in dst.
*/
-__attribute__((visibility("hidden")))
+LTTNG_HIDDEN
int utils_create_pipe(int *dst)
{
int ret;
* Make sure the pipe opened by this function are closed at some point. Use
* utils_close_pipe().
*/
-__attribute__((visibility("hidden")))
+LTTNG_HIDDEN
int utils_create_pipe_cloexec(int *dst)
{
int ret, i;
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.
*/
-__attribute__((visibility("hidden")))
+LTTNG_HIDDEN
void utils_close_pipe(int *src)
{
int i, ret;
/*
* Create a new string using two strings range.
*/
-__attribute__((visibility("hidden")))
+LTTNG_HIDDEN
char *utils_strdupdelim(const char *begin, const char *end)
{
char *str;
error:
return str;
}
+
+/*
+ * Set CLOEXEC flag to the give file descriptor.
+ */
+LTTNG_HIDDEN
+int utils_set_fd_cloexec(int fd)
+{
+ int ret;
+
+ if (fd < 0) {
+ ret = -EINVAL;
+ goto end;
+ }
+
+ ret = fcntl(fd, F_SETFD, FD_CLOEXEC);
+ if (ret < 0) {
+ PERROR("fcntl cloexec");
+ ret = -errno;
+ }
+
+end:
+ return ret;
+}
+
+/*
+ * Create pid file to the given path and filename.
+ */
+LTTNG_HIDDEN
+int utils_create_pid_file(pid_t pid, const char *filepath)
+{
+ int ret;
+ FILE *fp;
+
+ assert(filepath);
+
+ fp = fopen(filepath, "w");
+ if (fp == NULL) {
+ PERROR("open pid file %s", filepath);
+ ret = -1;
+ goto error;
+ }
+
+ ret = fprintf(fp, "%d\n", (int) pid);
+ if (ret < 0) {
+ PERROR("fprintf pid file");
+ goto error;
+ }
+
+ if (fclose(fp)) {
+ PERROR("fclose");
+ }
+ DBG("Pid %d written in file %s", (int) pid, filepath);
+ ret = 0;
+error:
+ return ret;
+}
+
+/*
+ * 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;
+ struct flock lock;
+
+ assert(filepath);
+
+ memset(&lock, 0, sizeof(lock));
+ fd = open(filepath, O_CREAT | O_WRONLY, S_IRUSR | S_IWUSR |
+ S_IRGRP | S_IWGRP);
+ if (fd < 0) {
+ PERROR("open lock file %s", filepath);
+ fd = -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.
+ */
+ lock.l_whence = SEEK_SET;
+ lock.l_type = F_WRLCK;
+
+ ret = fcntl(fd, F_SETLK, &lock);
+ if (ret == -1) {
+ PERROR("fcntl lock file");
+ 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;
+}
+
+/*
+ * On some filesystems (e.g. nfs), mkdir will validate access rights before
+ * checking for the existence of the path element. This means that on a setup
+ * where "/home/" is a mounted NFS share, and running as an unpriviledged user,
+ * recursively creating a path of the form "/home/my_user/trace/" will fail with
+ * EACCES on mkdir("/home", ...).
+ *
+ * Performing a stat(...) on the path to check for existence allows us to
+ * work around this behaviour.
+ */
+static
+int mkdir_check_exists(const char *path, mode_t mode)
+{
+ int ret = 0;
+ struct stat st;
+
+ ret = stat(path, &st);
+ if (ret == 0) {
+ if (S_ISDIR(st.st_mode)) {
+ /* Directory exists, skip. */
+ goto end;
+ } else {
+ /* Exists, but is not a directory. */
+ errno = ENOTDIR;
+ ret = -1;
+ goto end;
+ }
+ }
+
+ /*
+ * Let mkdir handle other errors as the caller expects mkdir
+ * semantics.
+ */
+ ret = mkdir(path, mode);
+end:
+ return ret;
+}
+
+/*
+ * Create directory using the given path and mode.
+ *
+ * On success, return 0 else a negative error code.
+ */
+LTTNG_HIDDEN
+int utils_mkdir(const char *path, mode_t mode, int uid, int gid)
+{
+ int ret;
+
+ if (uid < 0 || gid < 0) {
+ ret = mkdir_check_exists(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];
+ size_t len;
+ int ret;
+
+ assert(path);
+
+ ret = snprintf(tmp, sizeof(tmp), "%s", path);
+ if (ret < 0) {
+ PERROR("snprintf mkdir");
+ goto error;
+ }
+
+ len = ret;
+ if (tmp[len - 1] == '/') {
+ tmp[len - 1] = 0;
+ }
+
+ for (p = tmp + 1; *p; p++) {
+ if (*p == '/') {
+ *p = 0;
+ if (tmp[strlen(tmp) - 1] == '.' &&
+ tmp[strlen(tmp) - 2] == '.' &&
+ tmp[strlen(tmp) - 3] == '/') {
+ ERR("Using '/../' is not permitted in the trace path (%s)",
+ tmp);
+ ret = -1;
+ goto error;
+ }
+ ret = mkdir_check_exists(tmp, mode);
+ if (ret < 0) {
+ if (errno != EACCES) {
+ PERROR("mkdir recursive");
+ ret = -errno;
+ goto error;
+ }
+ }
+ *p = '/';
+ }
+ }
+
+ ret = mkdir_check_exists(tmp, mode);
+ if (ret < 0) {
+ PERROR("mkdir recursive last element");
+ ret = -errno;
+ }
+
+error:
+ return ret;
+}
+
+/*
+ * Recursively create directory using the given path and mode, under the
+ * provided uid and gid.
+ *
+ * On success, return 0 else a negative error code.
+ */
+LTTNG_HIDDEN
+int utils_mkdir_recursive(const char *path, mode_t mode, int uid, int gid)
+{
+ 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);
+ }
+
+ 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);
+ if (ret < 0) {
+ PERROR("snprintf create output file");
+ 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 (extra) {
+ ret = asprintf(&path_name_suffix, "%s%s", full_path, extra);
+ if (ret < 0) {
+ PERROR("Allocating path name with extra string");
+ goto error_free_suffix;
+ }
+ strncpy(path, path_name_suffix, PATH_MAX - 1);
+ path[PATH_MAX - 1] = '\0';
+ } else {
+ ret = lttng_strncpy(path, full_path, PATH_MAX);
+ if (ret) {
+ ERR("Failed to copy stream file name");
+ goto error_free_suffix;
+ }
+ }
+ 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;
+ }
+
+ /*
+ * With the session rotation feature on the relay, we might need to seek
+ * and truncate a tracefile, so we need read and write access.
+ */
+ flags = O_RDWR | O_CREAT | O_TRUNC;
+ /* Open with 660 mode */
+ mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP;
+
+ if (uid < 0 || gid < 0) {
+ ret = open(path, flags, mode);
+ } else {
+ ret = run_as_open(path, flags, mode, uid, gid);
+ }
+ if (ret < 0) {
+ PERROR("open stream path %s", path);
+ }
+error:
+ return ret;
+}
+
+/*
+ * 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;
+}
+
+/*
+ * Change the output tracefile according to the given size and count The
+ * new_count pointer is set during this operation.
+ *
+ * From the consumer, the stream lock MUST be held before calling this function
+ * because we are modifying the stream status.
+ *
+ * Return 0 on success or else a negative value.
+ */
+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,
+ int *stream_fd)
+{
+ int ret;
+
+ assert(stream_fd);
+
+ ret = close(out_fd);
+ if (ret < 0) {
+ PERROR("Closing tracefile");
+ goto error;
+ }
+ *stream_fd = -1;
+
+ 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.
+ */
+ if (new_count) {
+ *new_count = (*new_count + 1) % count;
+ }
+ ret = utils_unlink_stream_file(path_name, file_name, size,
+ new_count ? *new_count : 0, uid, gid, 0);
+ if (ret < 0 && errno != ENOENT) {
+ goto error;
+ }
+ } else {
+ if (new_count) {
+ (*new_count)++;
+ }
+ }
+
+ ret = utils_create_stream_file(path_name, file_name, size,
+ new_count ? *new_count : 0, uid, gid, 0);
+ if (ret < 0) {
+ goto error;
+ }
+ *stream_fd = ret;
+
+ /* Success. */
+ ret = 0;
+
+error:
+ return ret;
+}
+
+
+/**
+ * Parse a string that represents a size in human readable format. It
+ * supports decimal integers suffixed by 'k', 'K', 'M' or 'G'.
+ *
+ * The suffix multiply the integer by:
+ * 'k': 1024
+ * 'M': 1024^2
+ * 'G': 1024^3
+ *
+ * @param str The string to parse.
+ * @param size Pointer to a uint64_t that will be filled with the
+ * resulting size.
+ *
+ * @return 0 on success, -1 on failure.
+ */
+LTTNG_HIDDEN
+int utils_parse_size_suffix(const char * const str, uint64_t * const size)
+{
+ int ret;
+ uint64_t base_size;
+ long shift = 0;
+ const char *str_end;
+ char *num_end;
+
+ if (!str) {
+ DBG("utils_parse_size_suffix: received a NULL string.");
+ ret = -1;
+ goto end;
+ }
+
+ /* 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 end;
+ }
+
+ /* str_end will point to the \0 */
+ str_end = str + strlen(str);
+ errno = 0;
+ base_size = strtoull(str, &num_end, 0);
+ if (errno != 0) {
+ PERROR("utils_parse_size_suffix strtoull");
+ ret = -1;
+ goto end;
+ }
+
+ 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) {
+ DBG("utils_parse_size_suffix: oops, overflow detected.");
+ ret = -1;
+ goto end;
+ }
+
+ ret = 0;
+end:
+ return ret;
+}
+
+/**
+ * Parse a string that represents a time in human readable format. It
+ * supports decimal integers suffixed by 's', 'u', 'm', 'us', and 'ms'.
+ *
+ * The suffix multiply the integer by:
+ * 'u'/'us': 1
+ * 'm'/'ms': 1000
+ * 's': 1000000
+ *
+ * Note that unit-less numbers are assumed to be microseconds.
+ *
+ * @param str The string to parse, assumed to be NULL-terminated.
+ * @param time_us Pointer to a uint64_t that will be filled with the
+ * resulting time in microseconds.
+ *
+ * @return 0 on success, -1 on failure.
+ */
+LTTNG_HIDDEN
+int utils_parse_time_suffix(char const * const str, uint64_t * const time_us)
+{
+ int ret;
+ uint64_t base_time;
+ long multiplier = 1;
+ const char *str_end;
+ char *num_end;
+
+ if (!str) {
+ DBG("utils_parse_time_suffix: received a NULL string.");
+ ret = -1;
+ goto end;
+ }
+
+ /* strtoull will accept a negative number, but we don't want to. */
+ if (strchr(str, '-') != NULL) {
+ DBG("utils_parse_time_suffix: invalid time string, should not contain '-'.");
+ ret = -1;
+ goto end;
+ }
+
+ /* str_end will point to the \0 */
+ str_end = str + strlen(str);
+ errno = 0;
+ base_time = strtoull(str, &num_end, 10);
+ if (errno != 0) {
+ PERROR("utils_parse_time_suffix strtoull on string \"%s\"", str);
+ ret = -1;
+ goto end;
+ }
+
+ if (num_end == str) {
+ /* strtoull parsed nothing, not good. */
+ DBG("utils_parse_time_suffix: strtoull had nothing good to parse.");
+ ret = -1;
+ goto end;
+ }
+
+ /* Check if a prefix is present. */
+ switch (*num_end) {
+ case 'u':
+ multiplier = 1;
+ /* Skip another letter in the 'us' case. */
+ num_end += (*(num_end + 1) == 's') ? 2 : 1;
+ break;
+ case 'm':
+ multiplier = 1000;
+ /* Skip another letter in the 'ms' case. */
+ num_end += (*(num_end + 1) == 's') ? 2 : 1;
+ break;
+ case 's':
+ multiplier = 1000000;
+ num_end++;
+ break;
+ case '\0':
+ break;
+ default:
+ DBG("utils_parse_time_suffix: invalid suffix.");
+ ret = -1;
+ goto end;
+ }
+
+ /* Check for garbage after the valid input. */
+ if (num_end != str_end) {
+ DBG("utils_parse_time_suffix: Garbage after time string.");
+ ret = -1;
+ goto end;
+ }
+
+ *time_us = base_time * multiplier;
+
+ /* Check for overflow */
+ if ((*time_us / multiplier) != base_time) {
+ DBG("utils_parse_time_suffix: oops, overflow detected.");
+ ret = -1;
+ 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
+
+#if defined(__x86_64)
+static inline
+unsigned int fls_u64(uint64_t x)
+{
+ long r;
+
+ asm("bsrq %1,%0\n\t"
+ "jnz 1f\n\t"
+ "movq $-1,%0\n\t"
+ "1:\n\t"
+ : "=r" (r) : "rm" (x));
+ return r + 1;
+}
+#define HAS_FLS_U64
+#endif
+
+#ifndef HAS_FLS_U64
+static __attribute__((unused))
+unsigned int fls_u64(uint64_t x)
+{
+ unsigned int r = 64;
+
+ if (!x)
+ return 0;
+
+ if (!(x & 0xFFFFFFFF00000000ULL)) {
+ x <<= 32;
+ r -= 32;
+ }
+ if (!(x & 0xFFFF000000000000ULL)) {
+ x <<= 16;
+ r -= 16;
+ }
+ if (!(x & 0xFF00000000000000ULL)) {
+ x <<= 8;
+ r -= 8;
+ }
+ if (!(x & 0xF000000000000000ULL)) {
+ x <<= 4;
+ r -= 4;
+ }
+ if (!(x & 0xC000000000000000ULL)) {
+ x <<= 2;
+ r -= 2;
+ }
+ if (!(x & 0x8000000000000000ULL)) {
+ x <<= 1;
+ r -= 1;
+ }
+ return r;
+}
+#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);
+}
+
+/*
+ * Return the minimum order for which x <= (1UL << order).
+ * Return -1 if x is 0.
+ */
+LTTNG_HIDDEN
+int utils_get_count_order_u64(uint64_t x)
+{
+ if (!x) {
+ return -1;
+ }
+
+ return fls_u64(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);
+
+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;
+}
+
+/*
+ * 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 = lttng_dirfd(dir);
+ if (dir_fd < 0) {
+ PERROR("lttng_dirfd");
+ return -1;
+ }
+
+ path_len = strlen(path);
+ while ((entry = readdir(dir))) {
+ struct stat st;
+ size_t name_len;
+ char filename[PATH_MAX];
+
+ if (!strcmp(entry->d_name, ".")
+ || !strcmp(entry->d_name, "..")) {
+ continue;
+ }
+
+ 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;
+}
+
+LTTNG_HIDDEN
+int utils_truncate_stream_file(int fd, off_t length)
+{
+ int ret;
+ off_t lseek_ret;
+
+ ret = ftruncate(fd, length);
+ if (ret < 0) {
+ PERROR("ftruncate");
+ goto end;
+ }
+ lseek_ret = lseek(fd, length, SEEK_SET);
+ if (lseek_ret < 0) {
+ PERROR("lseek");
+ ret = -1;
+ goto end;
+ }
+end:
+ return ret;
+}
+
+static const char *get_man_bin_path(void)
+{
+ char *env_man_path = lttng_secure_getenv(DEFAULT_MAN_BIN_PATH_ENV);
+
+ if (env_man_path) {
+ return env_man_path;
+ }
+
+ return DEFAULT_MAN_BIN_PATH;
+}
+
+LTTNG_HIDDEN
+int utils_show_help(int section, const char *page_name,
+ const char *help_msg)
+{
+ char section_string[8];
+ const char *man_bin_path = get_man_bin_path();
+ int ret = 0;
+
+ if (help_msg) {
+ printf("%s", help_msg);
+ goto end;
+ }
+
+ /* Section integer -> section string */
+ ret = sprintf(section_string, "%d", section);
+ assert(ret > 0 && ret < 8);
+
+ /*
+ * Execute man pager.
+ *
+ * We provide -M to man here because LTTng-tools can
+ * be installed outside /usr, in which case its man pages are
+ * not located in the default /usr/share/man directory.
+ */
+ ret = execlp(man_bin_path, "man", "-M", MANPATH,
+ section_string, page_name, NULL);
+
+end:
+ return ret;
+}
+
+LTTNG_HIDDEN
+int timespec_to_ms(struct timespec ts, unsigned long *ms)
+{
+ unsigned long res, remain_ms;
+
+ if (ts.tv_sec > ULONG_MAX / MSEC_PER_SEC) {
+ errno = EOVERFLOW;
+ return -1; /* multiplication overflow */
+ }
+ res = ts.tv_sec * MSEC_PER_SEC;
+ remain_ms = ULONG_MAX - res;
+ if (ts.tv_nsec / NSEC_PER_MSEC > remain_ms) {
+ errno = EOVERFLOW;
+ return -1; /* addition overflow */
+ }
+ res += ts.tv_nsec / NSEC_PER_MSEC;
+ *ms = res;
+ return 0;
+}
+
+LTTNG_HIDDEN
+struct timespec timespec_abs_diff(struct timespec t1, struct timespec t2)
+{
+ uint64_t ts1 = (uint64_t) t1.tv_sec * (uint64_t) NSEC_PER_SEC +
+ (uint64_t) t1.tv_nsec;
+ uint64_t ts2 = (uint64_t) t2.tv_sec * (uint64_t) NSEC_PER_SEC +
+ (uint64_t) t2.tv_nsec;
+ uint64_t diff = max(ts1, ts2) - min(ts1, ts2);
+ struct timespec res;
+
+ res.tv_sec = diff / (uint64_t) NSEC_PER_SEC;
+ res.tv_nsec = diff % (uint64_t) NSEC_PER_SEC;
+ return res;
+}
projects / lttng-tools.git / blobdiff