diff options
Diffstat (limited to 'sysdeps/unix')
| -rw-r--r-- | sysdeps/unix/sysv/linux/check_pf.c | 193 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/ifaddrs.c | 10 |
2 files changed, 198 insertions, 5 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 +} diff --git a/sysdeps/unix/sysv/linux/ifaddrs.c b/sysdeps/unix/sysv/linux/ifaddrs.c index bc1ca8565f..837bfca664 100644 --- a/sysdeps/unix/sysv/linux/ifaddrs.c +++ b/sysdeps/unix/sysv/linux/ifaddrs.c @@ -41,7 +41,7 @@ /* We don't know if we have NETLINK support compiled in in our Kernel, so include the old implementation as fallback. */ #if __ASSUME_NETLINK_SUPPORT == 0 -static int no_netlink_support; +int __no_netlink_support attribute_hidden; # define getifaddrs fallback_getifaddrs # include "sysdeps/gnu/ifaddrs.c" @@ -49,7 +49,7 @@ static int no_netlink_support; #else -# define no_netlink_support 0 +# define __no_netlink_support 0 #endif @@ -297,17 +297,17 @@ getifaddrs (struct ifaddrs **ifap) if (ifap) *ifap = NULL; - if (! no_netlink_support && netlink_open (&nh) < 0) + if (! __no_netlink_support && netlink_open (&nh) < 0) { #if __ASSUME_NETLINK_SUPPORT == 0 - no_netlink_support = 1; + __no_netlink_support = 1; #else return -1; #endif } #if __ASSUME_NETLINK_SUPPORT == 0 - if (no_netlink_support) + if (__no_netlink_support) return fallback_getifaddrs (ifap); #endif |