#include <unistd.h>
#include <inttypes.h>
#include <regex.h>
+#include <grp.h>
#include <common/common.h>
#include <common/runas.h>
#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
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 */
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);
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.
*/
*/
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;
+}