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/*
* Copyright 2004 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include <sys/types.h>
#include <dirent.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include "webrtc/base/linuxfdwalk.h"
// Parses a file descriptor number in base 10, requiring the strict format used
// in /proc/*/fd. Returns the value, or -1 if not a valid string.
static int parse_fd(const char *s) {
if (!*s) {
// Empty string is invalid.
return -1;
}
int val = 0;
do {
if (*s < '0' || *s > '9') {
// Non-numeric characters anywhere are invalid.
return -1;
}
int digit = *s++ - '0';
val = val * 10 + digit;
} while (*s);
return val;
}
int fdwalk(void (*func)(void *, int), void *opaque) {
DIR *dir = opendir("/proc/self/fd");
if (!dir) {
return -1;
}
int opendirfd = dirfd(dir);
int parse_errors = 0;
struct dirent *ent;
// Have to clear errno to distinguish readdir() completion from failure.
while (errno = 0, (ent = readdir(dir)) != NULL) {
if (strcmp(ent->d_name, ".") == 0 ||
strcmp(ent->d_name, "..") == 0) {
continue;
}
// We avoid atoi or strtol because those are part of libc and they involve
// locale stuff, which is probably not safe from a post-fork context in a
// multi-threaded app.
int fd = parse_fd(ent->d_name);
if (fd < 0) {
parse_errors = 1;
continue;
}
if (fd != opendirfd) {
(*func)(opaque, fd);
}
}
int saved_errno = errno;
if (closedir(dir) < 0) {
if (!saved_errno) {
// Return the closedir error.
return -1;
}
// Else ignore it because we have a more relevant error to return.
}
if (saved_errno) {
errno = saved_errno;
return -1;
} else if (parse_errors) {
errno = EBADF;
return -1;
} else {
return 0;
}
}
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