Fix: Connect timeout arithmetic in inet/inet6 (v4)
[lttng-tools.git] / src / common / utils.c
index 7d018b53b1b9430cfb427761f9d4b4a4573e0334..08139e5e2cb23d691c92c6800cef841e2362bc57 100644 (file)
@@ -41,6 +41,7 @@
 
 #include "utils.h"
 #include "defaults.h"
+#include "time.h"
 
 /*
  * Return a partial realpath(3) of the path even if the full path does not
@@ -196,6 +197,106 @@ error:
        return NULL;
 }
 
+static
+int expand_double_slashes_dot_and_dotdot(char *path)
+{
+       size_t expanded_path_len, path_len;
+       const char *curr_char, *path_last_char, *next_slash, *prev_slash;
+
+       path_len = strlen(path);
+       path_last_char = &path[path_len];
+
+       if (path_len == 0) {
+               goto error;
+       }
+
+       expanded_path_len = 0;
+
+       /* We iterate over the provided path to expand the "//", "../" and "./" */
+       for (curr_char = path; curr_char <= path_last_char; curr_char = next_slash + 1) {
+               /* Find the next forward slash. */
+               size_t curr_token_len;
+
+               if (curr_char == path_last_char) {
+                       expanded_path_len++;
+                       break;
+               }
+
+               next_slash = memchr(curr_char, '/', path_last_char - curr_char);
+               if (next_slash == NULL) {
+                       /* Reached the end of the provided path. */
+                       next_slash = path_last_char;
+               }
+
+               /* Compute how long is the previous token. */
+               curr_token_len = next_slash - curr_char;
+               switch(curr_token_len) {
+               case 0:
+                       /*
+                        * The pointer has not move meaning that curr_char is
+                        * pointing to a slash. It that case there is no token
+                        * to copy, so continue the iteration to find the next
+                        * token
+                        */
+                       continue;
+               case 1:
+                       /*
+                        * The pointer moved 1 character. Check if that
+                        * character is a dot ('.'), if it is: omit it, else
+                        * copy the token to the normalized path.
+                        */
+                       if (curr_char[0] == '.') {
+                               continue;
+                       }
+                       break;
+               case 2:
+                       /*
+                        * The pointer moved 2 characters. Check if these
+                        * characters are double dots ('..'). If that is the
+                        * case, we need to remove the last token of the
+                        * normalized path.
+                        */
+                       if (curr_char[0] == '.' && curr_char[1] == '.') {
+                               /*
+                                * Find the previous path component by
+                                * using the memrchr function to find the
+                                * previous forward slash and substract that
+                                * len to the resulting path.
+                                */
+                               prev_slash = lttng_memrchr(path, '/', expanded_path_len);
+                               /*
+                                * If prev_slash is NULL, we reached the
+                                * beginning of the path. We can't go back any
+                                * further.
+                                */
+                               if (prev_slash != NULL) {
+                                       expanded_path_len = prev_slash - path;
+                               }
+                               continue;
+                       }
+                       break;
+               default:
+                       break;
+               }
+
+               /*
+                * Copy the current token which is neither a '.' nor a '..'.
+                */
+               path[expanded_path_len++] = '/';
+               memcpy(&path[expanded_path_len], curr_char, curr_token_len);
+               expanded_path_len += curr_token_len;
+       }
+
+       if (expanded_path_len == 0) {
+               path[expanded_path_len++] = '/';
+       }
+
+       path[expanded_path_len] = '\0';
+       return 0;
+error:
+       return -1;
+}
+
 /*
  * Make a full resolution of the given path even if it doesn't exist.
  * This function uses the utils_partial_realpath function to resolve
@@ -207,11 +308,12 @@ error:
  * the responsibility of the caller to free this memory.
  */
 LTTNG_HIDDEN
-char *utils_expand_path(const char *path)
+char *_utils_expand_path(const char *path, bool keep_symlink)
 {
-       char *next, *previous, *slash, *start_path, *absolute_path = NULL;
+       int ret;
+       char *absolute_path = NULL;
        char *last_token;
-       int is_dot, is_dotdot;
+       bool is_dot, is_dotdot;
 
        /* Safety net */
        if (path == NULL) {
@@ -219,67 +321,52 @@ char *utils_expand_path(const char *path)
        }
 
        /* Allocate memory for the absolute_path */
-       absolute_path = zmalloc(PATH_MAX);
+       absolute_path = zmalloc(LTTNG_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);
-
-       /* 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 = lttng_strndup(absolute_path, next - absolute_path);
-               if (!start_path) {
-                       PERROR("lttng_strndup");
+       if (path[0] == '/') {
+               ret = lttng_strncpy(absolute_path, path, LTTNG_PATH_MAX);
+               if (ret) {
+                       ERR("Path exceeds maximal size of %i bytes", LTTNG_PATH_MAX);
                        goto error;
                }
-               /* And we concatenate it with the part after this string */
-               snprintf(absolute_path, PATH_MAX, "%s%s", start_path, next + 2);
-
-               free(start_path);
-       }
+       } else {
+               /*
+                * This is a relative path. We need to get the present working
+                * directory and start the path walk from there.
+                */
+               char current_working_dir[LTTNG_PATH_MAX];
+               char *cwd_ret;
 
-       /* 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;
+               cwd_ret = getcwd(current_working_dir, sizeof(current_working_dir));
+               if (!cwd_ret) {
+                       goto error;
                }
-
-               /* Then we prepare the start_path not containing it */
-               start_path = lttng_strndup(absolute_path, previous - absolute_path);
-               if (!start_path) {
-                       PERROR("lttng_strndup");
+               /*
+                * Get the number of character in the CWD and allocate an array
+                * to can hold it and the path provided by the caller.
+                */
+               ret = snprintf(absolute_path, LTTNG_PATH_MAX, "%s/%s",
+                               current_working_dir, path);
+               if (ret >= LTTNG_PATH_MAX) {
+                       ERR("Concatenating current working directory %s and path %s exceeds maximal size of %i bytes",
+                                       current_working_dir, path, LTTNG_PATH_MAX);
                        goto error;
                }
+       }
 
-               /* 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 */
+       if (keep_symlink) {
+               /* Resolve partially our path */
                absolute_path = utils_partial_realpath(absolute_path,
-                               absolute_path, PATH_MAX);
+                               absolute_path, LTTNG_PATH_MAX);
+       }
+
+       ret = expand_double_slashes_dot_and_dotdot(absolute_path);
+       if (ret) {
+               goto error;
        }
 
        /* Identify the last token */
@@ -313,7 +400,17 @@ error:
        free(absolute_path);
        return NULL;
 }
+LTTNG_HIDDEN
+char *utils_expand_path(const char *path)
+{
+       return _utils_expand_path(path, true);
+}
 
+LTTNG_HIDDEN
+char *utils_expand_path_keep_symlink(const char *path)
+{
+       return _utils_expand_path(path, false);
+}
 /*
  * Create a pipe in dst.
  */
@@ -755,7 +852,11 @@ static int utils_stream_file_name(char *path,
                strncpy(path, path_name_suffix, PATH_MAX - 1);
                path[PATH_MAX - 1] = '\0';
        } else {
-               strncpy(path, full_path, PATH_MAX - 1);
+               ret = lttng_strncpy(path, full_path, PATH_MAX);
+               if (ret) {
+                       ERR("Failed to copy stream file name");
+                       goto error_free_suffix;
+               }
        }
        path[PATH_MAX - 1] = '\0';
        ret = 0;
@@ -1545,3 +1646,38 @@ int utils_show_help(int section, const char *page_name,
 end:
        return ret;
 }
+
+LTTNG_HIDDEN
+int timespec_to_ms(struct timespec ts, unsigned long *ms)
+{
+       unsigned long res, remain_ms;
+
+       if (ts.tv_sec > ULONG_MAX / MSEC_PER_SEC) {
+               errno = EOVERFLOW;
+               return -1;      /* multiplication overflow */
+       }
+       res = ts.tv_sec * MSEC_PER_SEC;
+       remain_ms = ULONG_MAX - res;
+       if (ts.tv_nsec / NSEC_PER_MSEC > remain_ms) {
+               errno = EOVERFLOW;
+               return -1;      /* addition overflow */
+       }
+       res += ts.tv_nsec / NSEC_PER_MSEC;
+       *ms = res;
+       return 0;
+}
+
+LTTNG_HIDDEN
+struct timespec timespec_abs_diff(struct timespec t1, struct timespec t2)
+{
+       uint64_t ts1 = (uint64_t) t1.tv_sec * (uint64_t) NSEC_PER_SEC +
+                       (uint64_t) t1.tv_nsec;
+       uint64_t ts2 = (uint64_t) t2.tv_sec * (uint64_t) NSEC_PER_SEC +
+                       (uint64_t) t2.tv_nsec;
+       uint64_t diff = max(ts1, ts2) - min(ts1, ts2);
+       struct timespec res;
+
+       res.tv_sec = diff / (uint64_t) NSEC_PER_SEC;
+       res.tv_nsec = diff % (uint64_t) NSEC_PER_SEC;
+       return res;
+}
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