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From b453f10d65dd1ff1df0dd3747adf63f4e1fd7d30 Mon Sep 17 00:00:00 2001

From: Alexander Chemeris <Alexander.Chemeris@gmail.com>
Date: Sun, 16 Dec 2012 17:44:10 +0400
Subject: [PATCH] Use gethostbyname2_r() instead of gethostbyname() if
 available.

gethostbyname() is not thread-safe. It's recommended to use gethostbyname_r() or gethostbyname2_r() instead.
---
 CommonLibs/Sockets.cpp |   44 +++++++++++++++++++++++++++++++++-----------
 configure.ac           |    4 ++++
 2 files changed, 37 insertions(+), 11 deletions(-)

git-svn-id: http://wush.net/svn/range/software/public/openbts/trunk@4637 19bc5d8c-e614-43d4-8b26-e1612bc8e597
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1 parent 762fb3b commit 9b5179627264e1c2494325bbc4b575a7836c0cf4 kurtis.heimerl committed Dec 17, 2012
Showing with 38 additions and 11 deletions.
  1. +34 −11 CommonLibs/Sockets.cpp
  2. +4 −0 configure.ac
View
45 CommonLibs/Sockets.cpp
@@ -25,6 +25,7 @@
+#include <config.h>
#include <unistd.h>
#include <fcntl.h>
#include <cstdio>
@@ -40,9 +41,6 @@
#include <stdlib.h>
-//mutex for protecting non-thread safe gethostbyname
-static Mutex sgGethostbynameLock;
-
bool resolveAddress(struct sockaddr_in *address, const char *hostAndPort)
{
assert(address);
@@ -62,16 +60,41 @@ bool resolveAddress(struct sockaddr_in *address, const char *host, unsigned shor
{
assert(address);
assert(host);
- //gethostbyname not thread safe
- ScopedLock lock(sgGethostbynameLock);
// FIXME -- Need to ignore leading/trailing spaces in hostname.
- struct hostent *hp = gethostbyname(host);
- if (hp==NULL) {
- CERR("WARNING -- gethostbyname() failed for " << host << ", " << hstrerror(h_errno));
+ struct hostent *hp;
+ int h_errno_local;
+#ifdef HAVE_GETHOSTBYNAME2_R
+ struct hostent hostData;
+ char tmpBuffer[2048];
+
+ // There are different flavors of gethostbyname_r(), but
+ // latest Linux use the following form:
+ if (gethostbyname2_r(host, AF_INET, &hostData, tmpBuffer, sizeof(tmpBuffer), &hp, &h_errno_local)!=0) {
+ CERR("WARNING -- gethostbyname2_r() failed for " << host << ", " << hstrerror(h_errno_local));
+ return false;
+ }
+#else
+ static Mutex sGethostbynameMutex;
+ // gethostbyname() is NOT thread-safe, so we should use a mutex here.
+ // Ideally it should be a global mutex for all non thread-safe socket
+ // operations and it should protect access to variables such as
+ // global h_errno.
+ sGethostbynameMutex.lock();
+ hp = gethostbyname(host);
+ h_errno_local = h_errno;
+ sGethostbynameMutex.unlock();
+#endif
+ if (hp==NULL) {
+ CERR("WARNING -- gethostbyname() failed for " << host << ", " << hstrerror(h_errno_local));
return false;
}
- address->sin_family = AF_INET;
- bcopy(hp->h_addr, &(address->sin_addr), hp->h_length);
+ if (hp->h_addrtype != AF_INET) {
+ CERR("WARNING -- gethostbyname() resolved " << host << " to something other then AF_INET");
+ return false;
+ }
+ address->sin_family = hp->h_addrtype;
+ assert(sizeof(address->sin_addr) == hp->h_length);
+ memcpy(&(address->sin_addr), hp->h_addr_list[0], hp->h_length);
address->sin_port = htons(port);
return true;
}
@@ -80,7 +103,7 @@ bool resolveAddress(struct sockaddr_in *address, const char *host, unsigned shor
DatagramSocket::DatagramSocket()
{
- bzero(mDestination,sizeof(mDestination));
+ memset(mDestination, 0, sizeof(mDestination));
}
View
4 configure.ac
@@ -130,6 +130,10 @@ PKG_CHECK_MODULES(LIBUSB, libusb-1.0)
# Prepends -lreadline to LIBS and defines HAVE_LIBREADLINE in config.h
AC_CHECK_LIB(readline, readline)
+# Check for glibc-specific network functions
+AC_CHECK_FUNC(gethostbyname_r, [AC_DEFINE(HAVE_GETHOSTBYNAME_R, 1, Define if libc implements gethostbyname_r)])
+AC_CHECK_FUNC(gethostbyname2_r, [AC_DEFINE(HAVE_GETHOSTBYNAME2_R, 1, Define if libc implements gethostbyname2_r)])
+
dnl Output files
AC_CONFIG_FILES([\
Makefile \

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