#include <common/compat/getenv.h>
#include <common/compat/string.h>
#include <common/compat/dirent.h>
+#include <common/compat/directory-handle.h>
+#include <common/dynamic-buffer.h>
#include <lttng/constant.h>
#include "utils.h"
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.
*
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:
+ struct lttng_directory_handle handle;
+ const struct lttng_credentials creds = {
+ .uid = (uid_t) uid,
+ .gid = (gid_t) gid,
+ };
+
+ (void) lttng_directory_handle_init(&handle, NULL);
+ ret = lttng_directory_handle_create_subdirectory_as_user(
+ &handle, path, mode,
+ (uid >= 0 || gid >= 0) ? &creds : NULL);
+ lttng_directory_handle_fini(&handle);
return ret;
}
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);
- }
-
+ struct lttng_directory_handle handle;
+ const struct lttng_credentials creds = {
+ .uid = (uid_t) uid,
+ .gid = (gid_t) gid,
+ };
+
+ (void) lttng_directory_handle_init(&handle, NULL);
+ ret = lttng_directory_handle_create_subdirectory_recursive_as_user(
+ &handle, path, mode,
+ (uid >= 0 || gid >= 0) ? &creds : NULL);
+ lttng_directory_handle_fini(&handle);
return ret;
}
}
/*
- * Return the group ID matching name, else 0 if it cannot be found.
+ * Return 0 on success and set *gid to the group_ID matching the passed name.
+ * Else -1 if it cannot be found or an error occurred.
*/
LTTNG_HIDDEN
-gid_t utils_get_group_id(const char *name)
+int utils_get_group_id(const char *name, bool warn, gid_t *gid)
{
- struct group *grp;
+ static volatile int warn_once;
+ int ret;
+ long sys_len;
+ size_t len;
+ struct group grp;
+ struct group *result;
+ struct lttng_dynamic_buffer buffer;
+
+ /* Get the system limit, if it exists. */
+ sys_len = sysconf(_SC_GETGR_R_SIZE_MAX);
+ if (sys_len == -1) {
+ len = 1024;
+ } else {
+ len = (size_t) sys_len;
+ }
+
+ lttng_dynamic_buffer_init(&buffer);
+ ret = lttng_dynamic_buffer_set_size(&buffer, len);
+ if (ret) {
+ ERR("Failed to allocate group info buffer");
+ ret = -1;
+ goto error;
+ }
- grp = getgrnam(name);
- if (!grp) {
- static volatile int warn_once;
+ while ((ret = getgrnam_r(name, &grp, buffer.data, buffer.size, &result)) == ERANGE) {
+ const size_t new_len = 2 * buffer.size;
- if (!warn_once) {
- WARN("No tracing group detected");
- warn_once = 1;
+ /* Buffer is not big enough, increase its size. */
+ if (new_len < buffer.size) {
+ ERR("Group info buffer size overflow");
+ ret = -1;
+ goto error;
+ }
+
+ ret = lttng_dynamic_buffer_set_size(&buffer, new_len);
+ if (ret) {
+ ERR("Failed to grow group info buffer to %zu bytes",
+ new_len);
+ ret = -1;
+ goto error;
}
- return 0;
}
- return grp->gr_gid;
+ if (ret) {
+ PERROR("Failed to get group file entry for group name \"%s\"",
+ name);
+ ret = -1;
+ goto error;
+ }
+
+ /* Group not found. */
+ if (!result) {
+ ret = -1;
+ goto error;
+ }
+
+ *gid = result->gr_gid;
+ ret = 0;
+
+error:
+ if (ret && warn && !warn_once) {
+ WARN("No tracing group detected");
+ warn_once = 1;
+ }
+ lttng_dynamic_buffer_reset(&buffer);
+ return ret;
}
/*
projects / lttng-tools.git / blobdiff