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