#include <inttypes.h>
#include <grp.h>
#include <pwd.h>
+#include <sys/file.h>
#include <common/common.h>
#include <common/runas.h>
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;
+ char *cut_path = NULL, *try_path = NULL, *try_path_prev = NULL;
const char *next, *prev, *end;
/* Safety net */
/* Cut the part we will be trying to resolve */
cut_path = strndup(path, next - path);
+ if (cut_path == NULL) {
+ PERROR("strndup");
+ goto error;
+ }
/* Try to resolve this part */
try_path = realpath((char *)cut_path, NULL);
/* Free the allocated memory */
free(cut_path);
+ cut_path = NULL;
};
/* Allocate memory for the resolved path if necessary */
* 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);
error:
free(resolved_path);
+ free(cut_path);
return NULL;
}
/* We prepare the start_path not containing it */
start_path = strndup(absolute_path, next - absolute_path);
-
+ if (!start_path) {
+ PERROR("strndup");
+ goto error;
+ }
/* And we concatenate it with the part after this string */
snprintf(absolute_path, PATH_MAX, "%s%s", start_path, next + 2);
/* Then we prepare the start_path not containing it */
start_path = strndup(absolute_path, previous - absolute_path);
+ if (!start_path) {
+ PERROR("strndup");
+ goto error;
+ }
/* And we concatenate it with the part after the '/../' */
snprintf(absolute_path, PATH_MAX, "%s%s", start_path, next + 4);
}
/*
- * 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) {
+ WARN("Could not get lock file %s, another instance is running.",
+ filepath);
+ close(fd);
+ 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];
size_t len;
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;
}
/*
- * 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(const char *path_name, char *file_name, uint64_t size,
- uint64_t count, int uid, int gid, char *suffix)
+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_suffix = NULL, *path;
- char *extra = NULL;
+ 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;
+}
- assert(path_name);
- assert(file_name);
+/*
+ * 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 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 (extra) {
ret = asprintf(&path_name_suffix, "%s%s", full_path, extra);
PERROR("Allocating path name with extra string");
goto error_free_suffix;
}
- path = path_name_suffix;
+ 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;
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_suffix);
-error_free_suffix:
- free(extra);
+/*
+ * 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;
}
}
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)++;
}
char *utils_get_home_dir(void)
{
char *val = NULL;
+ struct passwd *pwd;
+
val = getenv(DEFAULT_LTTNG_HOME_ENV_VAR);
if (val != NULL) {
- return val;
+ goto end;
+ }
+ val = getenv(DEFAULT_LTTNG_FALLBACK_HOME_ENV_VAR);
+ if (val != NULL) {
+ goto end;
}
- return getenv(DEFAULT_LTTNG_FALLBACK_HOME_ENV_VAR);
+
+ /* 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;
}
/**
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 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 getenv(DEFAULT_LTTNG_EXTRA_KMOD_PROBES);
+}
+
/*
* With the given format, fill dst with the time of len maximum siz.
*
projects / lttng-tools.git / blobdiff