From 3082bc6baeee32db8b437aca1072ca3a564f546c Mon Sep 17 00:00:00 2001 From: "/C=DE/ST=Berlin/L=Berlin/O=Netfilter Project/OU=Development/CN=laforge/emailAddress=laforge@netfilter.org" Date: Fri, 12 Aug 2005 12:34:44 +0000 Subject: add (but not use) rtnetlink source code for resolving ifindex<->devname --- src/rtnl.c | 246 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 246 insertions(+) create mode 100644 src/rtnl.c (limited to 'src/rtnl.c') diff --git a/src/rtnl.c b/src/rtnl.c new file mode 100644 index 0000000..50c3d42 --- /dev/null +++ b/src/rtnl.c @@ -0,0 +1,246 @@ +/* rtnl - rtnetlink utility functions + * + * (C) 2004 by Astaro AG, written by Harald Welte + * + * This software is free software and licensed under GNU GPLv2. + * + */ + +/* rtnetlink - routing table netlink interface */ + +#include +#include +#include +#include +#include +#include + +#include + +#include +#include +#include +#include + +#include "rtnl.h" + +#define rtnl_log(x, ...) + +static int rtnl_fd; +static int rtnl_seq = 0; +static int rtnl_dump; +static struct sockaddr_nl rtnl_local; + +static struct rtnl_handler *handlers = NULL; + +static inline struct rtnl_handler *find_handler(u_int16_t type) +{ + struct rtnl_handler *h; + for (h = handlers; h; h = h->next) { + if (h->nlmsg_type == type) + return h; + } + return NULL; +} + +static int call_handler(u_int16_t type, struct nlmsghdr *hdr) +{ + struct rtnl_handler *h = find_handler(type); + + if (!h) { + rtnl_log(LOG_DEBUG, "no registered handler for type %u", + type); + return 0; + } + + return (h->handlefn)(hdr, h->arg); +} + +/* rtnl_handler_register - register handler for given nlmsg type + * @hdlr: handler structure + */ +int rtnl_handler_register(struct rtnl_handler *hdlr) +{ + rtnl_log(LOG_DEBUG, "registering handler for type %u", + hdlr->nlmsg_type); + hdlr->next = handlers; + handlers = hdlr; + return 1; +} + +/* rtnl_handler_unregister - unregister handler for given nlmst type + * @hdlr: handler structure + */ +int rtnl_handler_unregister(struct rtnl_handler *hdlr) +{ + struct rtnl_handler *h, *prev = NULL; + + rtnl_log(LOG_DEBUG, "unregistering handler for type %u", + hdlr->nlmsg_type); + + for (h = handlers; h; h = h->next) { + if (h == hdlr) { + if (prev) + prev->next = h->next; + else + handlers = h->next; + return 1; + } + prev = h; + } + return 0; +} + +/* rtnl_arse_rtattr - parse rtattr */ +int rtnl_parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len) +{ + while (RTA_OK(rta, len)) { + if (rta->rta_type <= max) + tb[rta->rta_type] = rta; + rta = RTA_NEXT(rta,len); + } + if (len) + return -1; + return 0; +} + +/* rtnl_dump_type - ask rtnetlink to dump a specific table + * @type: type of table to be dumped + */ +int rtnl_dump_type(unsigned int type) +{ + struct { + struct nlmsghdr nlh; + struct rtgenmsg g; + } req; + struct sockaddr_nl nladdr; + + memset(&nladdr, 0, sizeof(nladdr)); + memset(&req, 0, sizeof(req)); + nladdr.nl_family = AF_NETLINK; + + req.nlh.nlmsg_len = sizeof(req); + req.nlh.nlmsg_type = type; + req.nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST; + req.nlh.nlmsg_pid = 0; + req.nlh.nlmsg_seq = rtnl_dump = ++rtnl_seq; + req.g.rtgen_family = AF_INET; + + return sendto(rtnl_fd, (void*)&req, sizeof(req), 0, + (struct sockaddr*)&nladdr, sizeof(nladdr)); +} + +/* rtnl_receive - receive netlink packets from rtnetlink socket */ +int rtnl_receive() +{ + int status; + char buf[8192]; + struct sockaddr_nl nladdr; + struct iovec iov = { buf, sizeof(buf) }; + struct nlmsghdr *h; + + struct msghdr msg = { + (void *)&nladdr, sizeof(nladdr), + &iov, 1, + NULL, 0, + 0 + }; + + status = recvmsg(rtnl_fd, &msg, 0); + if (status < 0) { + if (errno == EINTR) + return 0; + rtnl_log(LOG_NOTICE, "OVERRUN on rtnl socket"); + return -1; + } + if (status == 0) { + rtnl_log(LOG_ERROR, "EOF on rtnl socket"); + return -1; + } + if (msg.msg_namelen != sizeof(nladdr)) { + rtnl_log(LOG_ERROR, "invalid address size"); + return -1; + } + + h = (struct nlmsghdr *) buf; + while (NLMSG_OK(h, status)) { +#if 0 + if (h->nlmsg_pid != rtnl_local.nl_pid || + h->nlmsg_seq != rtnl_dump) { + goto skip; + } +#endif + + if (h->nlmsg_type == NLMSG_DONE) { + rtnl_log(LOG_NOTICE, "NLMSG_DONE"); + return 0; + } + if (h->nlmsg_type == NLMSG_ERROR) { + struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(h); + if (h->nlmsg_len>=NLMSG_LENGTH(sizeof(struct nlmsgerr))) + errno = -err->error; + rtnl_log(LOG_ERROR, "NLMSG_ERROR, errnp=%d", + errno); + return -1; + } + + if (call_handler(h->nlmsg_type, h) == 0) + rtnl_log(LOG_NOTICE, "unhandled nlmsg_type %u", + h->nlmsg_type); + h = NLMSG_NEXT(h, status); + } + return 1; +} + +/* rtnl_init - constructor of rtnetlink module */ +int rtnl_init(void) +{ + int addr_len; + + rtnl_local.nl_pid = getpid(); + rtnl_fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); + if (rtnl_fd < 0) { + rtnl_log(LOG_ERROR, "unable to create rtnetlink socket"); + return -1; + } + + memset(&rtnl_local, 0, sizeof(rtnl_local)); + rtnl_local.nl_family = AF_NETLINK; + rtnl_local.nl_groups = RTMGRP_IPV4_ROUTE|RTMGRP_IPV4_IFADDR|RTMGRP_LINK; + + if (bind(rtnl_fd, (struct sockaddr *)&rtnl_local, sizeof(rtnl_local)) < 0) { + rtnl_log(LOG_ERROR, "unable to bind rtnetlink socket"); + return -1; + } + + addr_len = sizeof(rtnl_local); + if (getsockname(rtnl_fd, (struct sockaddr *)&rtnl_local, + &addr_len) < 0) { + rtnl_log(LOG_ERROR, "cannot gescockname(rtnl_socket)"); + return -1; + } + + if (addr_len != sizeof(rtnl_local)) { + rtnl_log(LOG_ERROR, "invalid address size %u", addr_len); + return -1; + } + + if (rtnl_local.nl_family != AF_NETLINK) { + rtnl_log(LOG_ERROR, "invalid AF %u", rtnl_local.nl_family); + return -1; + } + + rtnl_seq = time(NULL); + + return rtnl_fd; +} + +/* rtnl_fini - destructor of rtnetlink module */ +void rtnl_fini(void) +{ + close(rtnl_fd); + return; +} + + + -- cgit v1.2.3