aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/unix/sysv/linux/check_pf.c
diff options
context:
space:
mode:
authorUlrich Drepper <drepper@redhat.com>2003-06-10 08:58:05 +0000
committerUlrich Drepper <drepper@redhat.com>2003-06-10 08:58:05 +0000
commit1dc869d13c77297661bf7ba4bde4c879818149da (patch)
tree286fc8327a3a4fdc742d90b8ca8bd278f3616b8d /sysdeps/unix/sysv/linux/check_pf.c
parent06120d793a3ae31f8f510f220c8a0a8e23b6a177 (diff)
downloadglibc-1dc869d13c77297661bf7ba4bde4c879818149da.tar
glibc-1dc869d13c77297661bf7ba4bde4c879818149da.tar.gz
glibc-1dc869d13c77297661bf7ba4bde4c879818149da.tar.bz2
glibc-1dc869d13c77297661bf7ba4bde4c879818149da.zip
Update.
* inet/Makefile (aux): Add check_fd. * include/ifaddrs.h: Add prototype for __check_fd. * sysdeps/generic/check_fd.c: New file. * sysdeps/unix/sysv/linux/check_fd.c: New file. * sysdeps/unix/sysv/linux/ifaddrs.h (__no_netlink_support): Renamed from no_netlink_support. Export. * sysdeps/posix/getaddrinfo.c (getaddrinfo): Don't call getifaddrs, call __check_pf. * sysdeps/generic/ifaddrs.h: Add libc_hidden_def.
Diffstat (limited to 'sysdeps/unix/sysv/linux/check_pf.c')
-rw-r--r--sysdeps/unix/sysv/linux/check_pf.c193
1 files changed, 193 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/check_pf.c b/sysdeps/unix/sysv/linux/check_pf.c
new file mode 100644
index 0000000000..0bc57daa51
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/check_pf.c
@@ -0,0 +1,193 @@
+/* Determine protocol families for which interfaces exist. Linux version.
+ Copyright (C) 2003 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <errno.h>
+#include <ifaddrs.h>
+#include <netdb.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+#include <sys/socket.h>
+
+#include <asm/types.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+
+#include "kernel-features.h"
+
+
+static int
+make_request (int fd, pid_t pid, bool *seen_ipv4, bool *seen_ipv6)
+{
+ struct
+ {
+ struct nlmsghdr nlh;
+ struct rtgenmsg g;
+ } req;
+ struct sockaddr_nl nladdr;
+
+ req.nlh.nlmsg_len = sizeof (req);
+ req.nlh.nlmsg_type = RTM_GETADDR;
+ req.nlh.nlmsg_flags = NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST;
+ req.nlh.nlmsg_pid = 0;
+ req.nlh.nlmsg_seq = time (NULL);
+ req.g.rtgen_family = AF_UNSPEC;
+
+ memset (&nladdr, '\0', sizeof (nladdr));
+ nladdr.nl_family = AF_NETLINK;
+
+ if (TEMP_FAILURE_RETRY (__sendto (fd, (void *) &req, sizeof (req), 0,
+ (struct sockaddr *) &nladdr,
+ sizeof (nladdr))) < 0)
+ return -1;
+
+ *seen_ipv4 = false;
+ *seen_ipv6 = false;
+
+ bool done = false;
+ char buf[4096];
+ struct iovec iov = { buf, sizeof (buf) };
+
+ do
+ {
+ struct msghdr msg =
+ {
+ (void *) &nladdr, sizeof (nladdr),
+ &iov, 1,
+ NULL, 0,
+ 0
+ };
+
+ ssize_t read_len = TEMP_FAILURE_RETRY (__recvmsg (fd, &msg, 0));
+ if (read_len < 0)
+ return -1;
+
+ if (msg.msg_flags & MSG_TRUNC)
+ return -1;
+
+ struct nlmsghdr *nlmh;
+ for (nlmh = (struct nlmsghdr *) buf;
+ NLMSG_OK (nlmh, (size_t) read_len);
+ nlmh = (struct nlmsghdr *) NLMSG_NEXT (nlmh, read_len))
+ {
+ if ((pid_t) nlmh->nlmsg_pid != pid
+ || nlmh->nlmsg_seq != req.nlh.nlmsg_seq)
+ continue;
+
+ if (nlmh->nlmsg_type == RTM_NEWADDR)
+ {
+ struct ifaddrmsg *ifam = (struct ifaddrmsg *) NLMSG_DATA (nlmh);
+
+ switch (ifam->ifa_family)
+ {
+ case AF_INET:
+ *seen_ipv4 = true;
+ break;
+ case AF_INET6:
+ *seen_ipv6 = true;
+ break;
+ default:
+ /* Ignore. */
+ break;
+ }
+ }
+ else if (nlmh->nlmsg_type == NLMSG_DONE)
+ /* We found the end, leave the loop. */
+ done = true;
+ else ;
+ }
+ }
+ while (! done);
+
+ close (fd);
+
+ return 0;
+}
+
+
+/* We don't know if we have NETLINK support compiled in in our
+ Kernel. */
+#if __ASSUME_NETLINK_SUPPORT == 0
+/* Define in ifaddrs.h. */
+extern int __no_netlink_support attribute_hidden;
+#else
+# define __no_netlink_support 0
+#endif
+
+
+void
+attribute_hidden
+__check_pf (bool *seen_ipv4, bool *seen_ipv6)
+{
+ if (! __no_netlink_support)
+ {
+ int fd = __socket (PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+
+ struct sockaddr_nl nladdr;
+ memset (&nladdr, '\0', sizeof (nladdr));
+ nladdr.nl_family = AF_NETLINK;
+
+ socklen_t addr_len = sizeof (nladdr);
+
+ if (fd >= 0
+ && __bind (fd, (struct sockaddr *) &nladdr, sizeof (nladdr)) == 0
+ && __getsockname (fd, (struct sockaddr *) &nladdr, &addr_len) == 0
+ && make_request (fd, nladdr.nl_pid, seen_ipv4, seen_ipv6) == 0)
+ /* It worked. */
+ return;
+
+ if (fd >= 0)
+ close (fd);
+
+#if __ASSUME_NETLINK_SUPPORT == 0
+ /* Remember that there is no netlink support. */
+ __no_netlink_support = 1;
+#else
+ /* We cannot determine what interfaces are available. Be
+ pessimistic. */
+ *seen_ipv4 = true;
+ *seen_ipv6 = true;
+#endif
+ }
+
+#if __ASSUME_NETLINK_SUPPORT == 0
+ /* No netlink. Get the interface list via getifaddrs. */
+ struct ifaddrs *ifa = NULL;
+ if (getifaddrs (&ifa) != 0)
+ {
+ /* We cannot determine what interfaces are available. Be
+ pessimistic. */
+ *seen_ipv4 = true;
+ *seen_ipv6 = true;
+ return;
+ }
+
+ *seen_ipv4 = false;
+ *seen_ipv6 = false;
+
+ struct ifaddrs *runp;
+ for (runp = ifa; runp != NULL; runp = runp->ifa_next)
+ if (runp->ifa_addr->sa_family == PF_INET)
+ *seen_ipv4 = true;
+ else if (runp->ifa_addr->sa_family == PF_INET6)
+ *seen_ipv6 = true;
+
+ (void) freeifaddrs (ifa);
+#endif
+}