/*
* Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
+ * Copyright (C) 2013 - Raphaël Beamonte <raphael.beamonte@gmail.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
#include <unistd.h>
#include <inttypes.h>
#include <regex.h>
+#include <grp.h>
#include <common/common.h>
#include <common/runas.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, *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");
- goto error;
+ /* 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;
+ }
}
- 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 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;
+}
+
+/*
+ * 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;
+
+ /* Safety net */
+ if (path == NULL) {
goto error;
}
- /* Add end part to expanded path */
- strncat(expanded_path, end_path, PATH_MAX - strlen(expanded_path) - 1);
+ /* Allocate memory for the absolute_path */
+ absolute_path = zmalloc(PATH_MAX);
+ if (absolute_path == NULL) {
+ PERROR("zmalloc expand path");
+ goto error;
+ }
+
+ /*
+ * 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);
- free(cut_path);
- return expanded_path;
+ /* 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 = 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 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;
+ }
+
+ /* 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 + 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);
+ }
+
+ return absolute_path;
error:
- free(expanded_path);
- free(cut_path);
+ free(absolute_path);
return NULL;
}
*/
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);
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;
}
ret = out_fd;
error_open:
- free(path_name_id);
+ free(path_name_suffix);
+error_free_suffix:
+ free(extra);
error:
return ret;
}
*/
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");
(*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;
}
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;
+}
projects / lttng-tools.git / blobdiff