Tests: move invalid tests in test_utils_expand_path that should be valid
[lttng-tools.git] / src / common / utils.c
index b345100ea0fa5ad6517d28c72cbc53a5bd87e391..6938a5ae52f6cac2e12465b37e3caafe8ae61d23 100644 (file)
@@ -27,6 +27,7 @@
 #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"
 
+/*
+ * 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 */
@@ -51,38 +120,80 @@ char *utils_expand_path(const char *path)
                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);
@@ -351,10 +462,11 @@ error:
  */
 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);
@@ -366,17 +478,30 @@ int utils_create_stream_file(const char *path_name, char *file_name, uint64_t si
                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;
        }
@@ -397,7 +522,9 @@ int utils_create_stream_file(const char *path_name, char *file_name, uint64_t si
        ret = out_fd;
 
 error_open:
-       free(path_name_id);
+       free(path_name_suffix);
+error_free_suffix:
+       free(extra);
 error:
        return ret;
 }
@@ -413,10 +540,14 @@ error:
  */
 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");
@@ -429,8 +560,16 @@ int utils_rotate_stream_file(char *path_name, char *file_name, uint64_t size,
                (*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;
 }
@@ -666,3 +805,24 @@ size_t utils_get_current_time_str(const char *format, char *dst, size_t 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;
+}
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