trunk/talk git-svn-id: http://webrtc.googlecode.com/svn/trunk@4318 4adac7df-926f-26a2-2b94-8c16560cd09d
		
			
				
	
	
		
			99 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			99 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * libjingle
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 * Copyright 2004--2009, Google Inc.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions are met:
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 *
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 *  1. Redistributions of source code must retain the above copyright notice,
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 *     this list of conditions and the following disclaimer.
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 *  2. Redistributions in binary form must reproduce the above copyright notice,
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 *     this list of conditions and the following disclaimer in the documentation
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 *     and/or other materials provided with the distribution.
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 *  3. The name of the author may not be used to endorse or promote products
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 *     derived from this software without specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
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 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
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 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
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 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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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 "talk/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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