From: Benjamin Cama Date: Sun, 14 Aug 2011 20:56:35 +0000 (+0200) Subject: First netlink functions. X-Git-Tag: debian/2.2.1-1fdn2~2^2^2~15 X-Git-Url: http://git.sameswireless.fr/l2tpns.git/commitdiff_plain/c7b02a09277af710d0e77813ca644a50737e9ac5 First netlink functions. Signed-off-by: Benjamin Cama --- diff --git a/l2tpns.c b/l2tpns.c index 8fdcb53..af19f9a 100644 --- a/l2tpns.c +++ b/l2tpns.c @@ -39,6 +39,7 @@ char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.176 2011/01/20 12:48:40 bodea Exp #include #include #include +#include #include "md5.h" #include "l2tpns.h" @@ -56,6 +57,7 @@ char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.176 2011/01/20 12:48:40 bodea Exp // Globals configt *config = NULL; // all configuration +int nlfd = -1; // netlink socket int tunfd = -1; // tun interface file handle. (network device) int udpfd = -1; // UDP file handle int controlfd = -1; // Control signal handle @@ -71,6 +73,7 @@ int epollfd = -1; // event polling time_t basetime = 0; // base clock char hostname[1000] = ""; // us. static int tunidx; // ifr_ifindex of tun device +int nlseqnum = 0; // netlink sequence number static int syslog_log = 0; // are we logging to syslog static FILE *log_stream = 0; // file handle for direct logging (i.e. direct into file, not via syslog). uint32_t last_id = 0; // Unique ID for radius accounting @@ -514,6 +517,79 @@ void route6set(sessionidt s, struct in6_addr ip, int prefixlen, int add) return; } +// +// Set up netlink socket +static void initnetlink(void) +{ + struct sockaddr_nl nladdr; + + nlfd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); + if (nlfd < 0) + return; // don't use netlink + + memset(&nladdr, 0, sizeof(nladdr)); + nladdr.nl_family = AF_NETLINK; + nladdr.nl_pid = getpid(); + + if (bind(fd, (struct sockaddr *)&nladdr, sizeof(nladdr)) < 0) + { + close(fd); + fd = -1; + return; // don't use netlink + } +} + +static ssize_t netlink_send(struct nlmsghdr *nh) +{ + struct sockaddr_nl nladdr; + struct iovec iov; + struct msghdr msg; + ssize_t len; + char buf[4096]; + struct nlmsghdr *ack_nh; + + nh->nlmsg_pid = getpid(); + nh->nlmsg_seq = ++nlseqnum; + nh->nlmsg_flags |= NLM_F_ACK; + + iov = { (void *)nh, nh->msg_len }; + // set kernel address + memset(nladdr, 0, sizeof(nladdr)); + nladdr.nl_family = AF_NETLINK; + msg = { (void *)&nladdr, sizeof(nladdr), &iov, 1, NULL, 0, 0 }; + + if ((len = sendmsg(nlfd, &msg, 0)) < 0) + return len; // return error code + + // expect ack + iov = { buf, sizeof(buf) }; + msg = { (void *)&nladdr, sizeof(nladdr), &iov, 1, NULL, 0, 0 }; + if ((len = recvmsg(nlfd, &msg, 0)) < 0) + return len; // return error code + + for (ack_nh = (struct nlmsghdr *)buf; NLMSG_OK (ack_nh, len); + ack_nh = NLMSG_NEXT (ack_nh, len)) + { + if (ack_nh->nlmsg_type == NLMSG_DONE) + return 1; // didn't get the ack + + if (ack_nh->nlmsg_type == NLMSG_ERROR) + { + struct nlmsgerr *errmsg = NLMSG_DATA(ack_nh); + if (errmsg->error) + return errmsg->error; // got an error back + if (errmsg->msg.nlmsg_seq == nh->nlmsg_seq) + return 0; // ack received + else + return 2; // wrong seq number?! + } + // unknown message + LOG(3, 0, 0, "Got an unknown netlink message: type %d\n", ack_nh->nlmsg_type); + } + + return 3; // no end message?! +} + // defined in linux/ipv6.h, but tricky to include from user-space // TODO: move routing to use netlink rather than ioctl struct in6_ifreq { @@ -549,6 +625,14 @@ static void inittun(void) } assert(strlen(ifr.ifr_name) < sizeof(config->tundevice)); strncpy(config->tundevice, ifr.ifr_name, sizeof(config->tundevice) - 1); + { + struct nlmsghdr nlh; + + { + LOG(0, 0, 0, "Error setting up tun device: %s", strerror(errno)); + exit(1); + } + } ifrfd = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP); sin.sin_family = AF_INET;