/*
* Utility functions to track file descriptors.
*
- * Copyright (C) 2013 Simon Ruderich
+ * Copyright (C) 2013-2015 Simon Ruderich
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
}
#endif
+/* Check if filename occurs in the comma-separated list ignore. */
+static int is_program_ignored(char const *filename, char const *ignore) {
+ size_t length;
+ size_t filename_length = strlen(filename);
+
+#ifdef DEBUG
+ debug(" is_program_ignored(\"%s\", \"%s\")\n", filename, ignore);
+#endif
+
+ for (; *ignore; ignore += length) {
+ while (*ignore == ',') {
+ ignore++;
+ }
+
+ length = strcspn(ignore, ",");
+ if (length == 0) {
+ break;
+ }
+
+ if (length != filename_length) {
+ continue;
+ }
+ if (!strncmp(filename, ignore, length)) {
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
static int init_tracked_fds_list(size_t count) {
+ assert(count > 0);
+
/* Reduce reallocs. */
count += TRACKFDS_REALLOC_STEP;
tracked_fds_list = malloc(count * sizeof(*tracked_fds_list));
if (!tracked_fds_list) {
-#ifdef DEBUG
+#ifdef WARNING
warning("malloc(tracked_fds_list, %d) failed [%d]\n",
count * sizeof(*tracked_fds_list), getpid());
#endif
return 1;
}
-/* Load tracked file descriptors from the environment. The environment is used
+/*
+ * Load tracked file descriptors from the environment. The environment is used
* to pass the information to child processes.
*
- * ENV_NAME_FDS has the following format: Each descriptor as string followed
- * by a comma; there's a trailing comma. Example: "2,4,". */
+ * ENV_NAME_FDS and ENV_NAME_PRIVATE_FDS have the following format: Each
+ * descriptor as string followed by a comma; there's a trailing comma.
+ * Example: "2,4,".
+ */
static void init_from_environment(void) {
#ifdef DEBUG
debug("init_from_environment()\t\t[%d]\n", getpid());
int saved_errno = errno;
+ assert(!initialized);
+
initialized = 1;
tracked_fds_list_count = 0;
+ /* Don't color writes to stderr for this binary (and its children) if it's
+ * contained in the comma-separated list in ENV_NAME_IGNORED_BINARIES. */
+ env = getenv(ENV_NAME_IGNORED_BINARIES);
+ if (env) {
+ char path[512];
+
+ /* TODO: Don't require /proc/. */
+ ssize_t written = readlink("/proc/self/exe", path, sizeof(path) - 1);
+ if (written > 0) {
+ path[written] = 0; /* readlink() does not null-terminate! */
+ if (is_program_ignored(path, env)) {
+ return;
+ }
+ }
+ }
+
/* If ENV_NAME_FORCE_WRITE is set and not empty, allow writes to a non-tty
* device. Use with care! Mainly used for the test suite. */
env = getenv(ENV_NAME_FORCE_WRITE);
force_write_to_non_tty = 1;
}
+ /* Prefer user defined list of file descriptors, fall back to file
+ * descriptors passed through the environment from the parent process. */
env = getenv(ENV_NAME_FDS);
+ if (env) {
+ used_fds_set_by_user = 1;
+ } else {
+ env = getenv(ENV_NAME_PRIVATE_FDS);
+ }
if (!env) {
errno = saved_errno;
return;
}
- /* Environment is read-only. */
+#ifdef DEBUG
+ debug(" getenv(\"%s\"): \"%s\"\n", ENV_NAME_FDS, env);
+ debug(" getenv(\"%s\"): \"%s\"\n", ENV_NAME_PRIVATE_FDS, env);
+#endif
+
+ /* Environment must be treated read-only. */
char env_copy[strlen(env) + 1];
strcpy(env_copy, env);
}
/* ',' at the beginning or double ',' - ignore. */
if (x == last) {
- last = x + 1;
- continue;
- }
-
- if (i == count) {
- break;
+ goto next;
}
+ /* Replace ',' to null-terminate number for atoi(). */
*x = 0;
int fd = atoi(last);
- if (fd < TRACKFDS_STATIC_COUNT) {
+ if (fd < 0) {
+ goto next;
+
+ } else if (fd < TRACKFDS_STATIC_COUNT) {
tracked_fds[fd] = 1;
} else {
if (!tracked_fds_list) {
}
static char *update_environment_buffer_entry(char *x, int fd) {
+ assert(fd >= 0);
+
int length = snprintf(x, 10 + 1, "%d", fd);
- if (length >= 10 + 1) {
+ if (length >= 10 + 1 || length <= 0 /* shouldn't happen */) {
/* Integer too big to fit the buffer, skip it. */
-#ifdef DEBUG
+#ifdef WARNING
warning("update_environment_buffer_entry(): truncated fd: %d [%d]\n",
fd, getpid());
#endif
/* Write comma after number. */
x += length;
*x++ = ',';
- /* Make sure the string is always zero terminated. */
+ /* Make sure the string is always null-terminated. */
*x = 0;
return x;
}
static void update_environment_buffer(char *x) {
+ assert(initialized);
+
size_t i;
for (i = 0; i < TRACKFDS_STATIC_COUNT; i++) {
if (tracked_fds[i]) {
}
}
inline static size_t update_environment_buffer_size(void) {
+ assert(initialized);
+
/* Use the maximum count (TRACKFDS_STATIC_COUNT) of used descriptors
* because it's simple and small enough not to be a problem.
*
return;
}
+ int saved_errno = errno;
+
char env[update_environment_buffer_size()];
env[0] = 0;
update_environment_buffer(env);
#if 0
- debug(" setenv('%s', '%s', 1)\n", ENV_NAME_FDS, env);
+ debug(" setenv(\"%s\", \"%s\", 1)\n", ENV_NAME_PRIVATE_FDS, env);
#endif
+ setenv(ENV_NAME_PRIVATE_FDS, env, 1 /* overwrite */);
+
+ /* Child processes must use ENV_NAME_PRIVATE_FDS to get the updated list
+ * of tracked file descriptors, not the static list provided by the user
+ * in ENV_NAME_FDS.
+ *
+ * But only remove it if the static list in ENV_NAME_FDS was loaded by
+ * init_from_environment() and merged into ENV_NAME_PRIVATE_FDS. */
+ if (used_fds_set_by_user) {
+ unsetenv(ENV_NAME_FDS);
+ }
- setenv(ENV_NAME_FDS, env, 1 /* overwrite */);
+ errno = saved_errno;
}
static void tracked_fds_add(int fd) {
+ assert(fd >= 0);
+
if (fd < TRACKFDS_STATIC_COUNT) {
tracked_fds[fd] = 1;
#if 0
/* We can do nothing, just ignore the error. We made sure not to
* destroy our state, so the new descriptor is ignored without any
* other consequences. */
-#ifdef DEBUG
+#ifdef WARNING
warning("realloc(tracked_fds_list, %zu) failed! [%d]\n",
sizeof(*tracked_fds_list) * new_space, getpid());
#endif
#endif
}
static int tracked_fds_remove(int fd) {
+ assert(fd >= 0);
+
if (fd < TRACKFDS_STATIC_COUNT) {
int old_value = tracked_fds[fd];
tracked_fds[fd] = 0;
return 0;
}
-static int tracked_fds_find_slow(int fd) __noinline;
+static int tracked_fds_find_slow(int fd) noinline;
/*
* tracked_fds_find() is called for each hook call and should be as fast as
* possible. As most file descriptors are < TRACKFDS_STATIC_COUNT, force the
* Inlining tracked_fds_add()/tracked_fds_remove() isn't worth the effort as
* they are not called often enough.
*/
-inline static int tracked_fds_find(int fd) __always_inline;
-static int tracked_fds_find(int fd) {
- if (fd < TRACKFDS_STATIC_COUNT) {
+inline static int tracked_fds_find(int fd) always_inline;
+inline static int tracked_fds_find(int fd) {
+ /* Invalid file descriptor. No assert() as we're called from the hooked
+ * macro. */
+ if (unlikely(fd < 0)) {
+ return 0;
+ }
+
+ if (likely(fd < TRACKFDS_STATIC_COUNT)) {
return tracked_fds[fd];
}
return tracked_fds_find_slow(fd);
}
static int tracked_fds_find_slow(int fd) {
+ assert(initialized);
+ assert(fd >= 0);
+
if (tracked_fds_list_count == 0) {
return 0;
}
ruderich.org/simon / coloredstderr / coloredstderr.git / blobdiff