diff options
Diffstat (limited to 'src/rtnl.c')
-rw-r--r-- | src/rtnl.c | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/src/rtnl.c b/src/rtnl.c new file mode 100644 index 0000000..5ccb272 --- /dev/null +++ b/src/rtnl.c @@ -0,0 +1,266 @@ +/* rtnl - rtnetlink utility functions + * + * (C) 2004 by Astaro AG, written by Harald Welte <hwelte@astaro.com> + * + * Adapted to nfnetlink by Eric Leblond <eric@inl.fr> + * + * This software is free software and licensed under GNU GPLv2. + * + */ + +/* rtnetlink - routing table netlink interface */ + +#include <unistd.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <time.h> +#include <sys/types.h> +#include <sys/uio.h> + +#include <netinet/in.h> + +#include <linux/types.h> +#include <sys/socket.h> +#include <linux/netlink.h> +#include <linux/rtnetlink.h> + +#include "rtnl.h" + +#define rtnl_log(x, ...) + +static inline struct rtnl_handler * +find_handler(struct rtnl_handle *rtnl_handle, u_int16_t type) +{ + struct rtnl_handler *h; + for (h = rtnl_handle->handlers; h; h = h->next) { + if (h->nlmsg_type == type) + return h; + } + return NULL; +} + +static int call_handler(struct rtnl_handle *rtnl_handle, + u_int16_t type, + struct nlmsghdr *hdr) +{ + struct rtnl_handler *h = find_handler(rtnl_handle, 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_handle *rtnl_handle, + struct rtnl_handler *hdlr) +{ + rtnl_log(LOG_DEBUG, "registering handler for type %u", + hdlr->nlmsg_type); + hdlr->next = rtnl_handle->handlers; + rtnl_handle->handlers = hdlr; + return 1; +} + +/* rtnl_handler_unregister - unregister handler for given nlmst type + * @hdlr: handler structure + */ +int rtnl_handler_unregister(struct rtnl_handle *rtnl_handle, + struct rtnl_handler *hdlr) +{ + struct rtnl_handler *h, *prev = NULL; + + rtnl_log(LOG_DEBUG, "unregistering handler for type %u", + hdlr->nlmsg_type); + + for (h = rtnl_handle->handlers; h; h = h->next) { + if (h == hdlr) { + if (prev) + prev->next = h->next; + else + rtnl_handle->handlers = h->next; + return 1; + } + prev = h; + } + return 0; +} + +int rtnl_parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len) +{ + memset(tb, 0, sizeof(struct rtattr *) * max); + + 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(struct rtnl_handle *rtnl_handle, 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_handle->rtnl_dump = ++(rtnl_handle->rtnl_seq); + req.g.rtgen_family = AF_INET; + + return sendto(rtnl_handle->rtnl_fd, &req, sizeof(req), 0, + (struct sockaddr*)&nladdr, sizeof(nladdr)); +} + +/* rtnl_receive - receive netlink packets from rtnetlink socket */ +int rtnl_receive(struct rtnl_handle *rtnl_handle) +{ + int status; + char buf[8192]; + struct sockaddr_nl nladdr; + struct iovec iov = { buf, sizeof(buf) }; + struct nlmsghdr *h; + + struct msghdr msg = { + .msg_name = &nladdr, + .msg_namelen = sizeof(nladdr), + .msg_iov = &iov, + .msg_iovlen = 1, + }; + + status = recvmsg(rtnl_handle->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 = 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(rtnl_handle, h->nlmsg_type, h) == 0) + rtnl_log(LOG_NOTICE, "unhandled nlmsg_type %u", + h->nlmsg_type); + h = NLMSG_NEXT(h, status); + } + return 1; +} + +int rtnl_receive_multi(struct rtnl_handle *rtnl_handle) +{ + while (1) { + if (rtnl_receive(rtnl_handle) <= 0) + break; + } + return 1; +} + +/* rtnl_open - constructor of rtnetlink module */ +struct rtnl_handle *rtnl_open(void) +{ + socklen_t addrlen; + struct rtnl_handle *h; + + h = calloc(1, sizeof(struct rtnl_handle)); + if (!h) + return NULL; + + addrlen = sizeof(h->rtnl_local); + + h->rtnl_local.nl_pid = getpid(); + h->rtnl_fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); + if (h->rtnl_fd < 0) { + rtnl_log(LOG_ERROR, "unable to create rtnetlink socket"); + goto err; + } + + memset(&h->rtnl_local, 0, sizeof(h->rtnl_local)); + h->rtnl_local.nl_family = AF_NETLINK; + h->rtnl_local.nl_groups = RTMGRP_LINK; + if (bind(h->rtnl_fd, (struct sockaddr *) &h->rtnl_local, addrlen) < 0) { + rtnl_log(LOG_ERROR, "unable to bind rtnetlink socket"); + goto err_close; + } + + if (getsockname(h->rtnl_fd, + (struct sockaddr *) &h->rtnl_local, + &addrlen) < 0) { + rtnl_log(LOG_ERROR, "cannot gescockname(rtnl_socket)"); + goto err_close; + } + + if (addrlen != sizeof(h->rtnl_local)) { + rtnl_log(LOG_ERROR, "invalid address size %u", addr_len); + goto err_close; + } + + if (h->rtnl_local.nl_family != AF_NETLINK) { + rtnl_log(LOG_ERROR, "invalid AF %u", h->rtnl_local.nl_family); + goto err_close; + } + + h->rtnl_seq = time(NULL); + + return h; + +err_close: + close(h->rtnl_fd); +err: + free(h); + return NULL; +} + +/* rtnl_close - destructor of rtnetlink module */ +void rtnl_close(struct rtnl_handle *rtnl_handle) +{ + close(rtnl_handle->rtnl_fd); + free(rtnl_handle); + return; +} |