diff options
Diffstat (limited to 'busybox/networking/libiproute/libnetlink.c')
| -rw-r--r-- | busybox/networking/libiproute/libnetlink.c | 524 |
1 files changed, 524 insertions, 0 deletions
diff --git a/busybox/networking/libiproute/libnetlink.c b/busybox/networking/libiproute/libnetlink.c new file mode 100644 index 0000000..5545be8 --- /dev/null +++ b/busybox/networking/libiproute/libnetlink.c @@ -0,0 +1,524 @@ +/* + * libnetlink.c RTnetlink service routines. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> + * + */ + +#include <sys/socket.h> + +#include <errno.h> +#include <stdio.h> +#include <string.h> +#include <time.h> +#include <unistd.h> + +#include <sys/uio.h> + +#include "libnetlink.h" +#include "libbb.h" + +void rtnl_close(struct rtnl_handle *rth) +{ + close(rth->fd); +} + +int rtnl_open(struct rtnl_handle *rth, unsigned subscriptions) +{ + int addr_len; + + memset(rth, 0, sizeof(rth)); + + rth->fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); + if (rth->fd < 0) { + bb_perror_msg("Cannot open netlink socket"); + return -1; + } + + memset(&rth->local, 0, sizeof(rth->local)); + rth->local.nl_family = AF_NETLINK; + rth->local.nl_groups = subscriptions; + + if (bind(rth->fd, (struct sockaddr*)&rth->local, sizeof(rth->local)) < 0) { + bb_perror_msg("Cannot bind netlink socket"); + return -1; + } + addr_len = sizeof(rth->local); + if (getsockname(rth->fd, (struct sockaddr*)&rth->local, &addr_len) < 0) { + bb_perror_msg("Cannot getsockname"); + return -1; + } + if (addr_len != sizeof(rth->local)) { + bb_error_msg("Wrong address length %d", addr_len); + return -1; + } + if (rth->local.nl_family != AF_NETLINK) { + bb_error_msg("Wrong address family %d", rth->local.nl_family); + return -1; + } + rth->seq = time(NULL); + return 0; +} + +int rtnl_wilddump_request(struct rtnl_handle *rth, int family, int type) +{ + struct { + struct nlmsghdr nlh; + struct rtgenmsg g; + } req; + struct sockaddr_nl nladdr; + + memset(&nladdr, 0, sizeof(nladdr)); + 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 = rth->dump = ++rth->seq; + req.g.rtgen_family = family; + + return sendto(rth->fd, (void*)&req, sizeof(req), 0, (struct sockaddr*)&nladdr, sizeof(nladdr)); +} + +int rtnl_send(struct rtnl_handle *rth, char *buf, int len) +{ + struct sockaddr_nl nladdr; + + memset(&nladdr, 0, sizeof(nladdr)); + nladdr.nl_family = AF_NETLINK; + + return sendto(rth->fd, buf, len, 0, (struct sockaddr*)&nladdr, sizeof(nladdr)); +} + +int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len) +{ + struct nlmsghdr nlh; + struct sockaddr_nl nladdr; + struct iovec iov[2] = { { &nlh, sizeof(nlh) }, { req, len } }; + struct msghdr msg = { + (void*)&nladdr, sizeof(nladdr), + iov, 2, + NULL, 0, + 0 + }; + + memset(&nladdr, 0, sizeof(nladdr)); + nladdr.nl_family = AF_NETLINK; + + nlh.nlmsg_len = NLMSG_LENGTH(len); + nlh.nlmsg_type = type; + nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST; + nlh.nlmsg_pid = 0; + nlh.nlmsg_seq = rth->dump = ++rth->seq; + + return sendmsg(rth->fd, &msg, 0); +} + +int rtnl_dump_filter(struct rtnl_handle *rth, + int (*filter)(struct sockaddr_nl *, struct nlmsghdr *n, void *), + void *arg1, + int (*junk)(struct sockaddr_nl *,struct nlmsghdr *n, void *), + void *arg2) +{ + char buf[8192]; + struct sockaddr_nl nladdr; + struct iovec iov = { buf, sizeof(buf) }; + + while (1) { + int status; + struct nlmsghdr *h; + + struct msghdr msg = { + (void*)&nladdr, sizeof(nladdr), + &iov, 1, + NULL, 0, + 0 + }; + + status = recvmsg(rth->fd, &msg, 0); + + if (status < 0) { + if (errno == EINTR) + continue; + bb_perror_msg("OVERRUN"); + continue; + } + if (status == 0) { + bb_error_msg("EOF on netlink"); + return -1; + } + if (msg.msg_namelen != sizeof(nladdr)) { + bb_error_msg_and_die("sender address length == %d", msg.msg_namelen); + } + + h = (struct nlmsghdr*)buf; + while (NLMSG_OK(h, status)) { + int err; + + if (nladdr.nl_pid != 0 || + h->nlmsg_pid != rth->local.nl_pid || + h->nlmsg_seq != rth->dump) { + if (junk) { + err = junk(&nladdr, h, arg2); + if (err < 0) { + return err; + } + } + goto skip_it; + } + + if (h->nlmsg_type == NLMSG_DONE) { + return 0; + } + if (h->nlmsg_type == NLMSG_ERROR) { + struct nlmsgerr *l_err = (struct nlmsgerr*)NLMSG_DATA(h); + if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) { + bb_error_msg("ERROR truncated"); + } else { + errno = -l_err->error; + bb_perror_msg("RTNETLINK answers"); + } + return -1; + } + err = filter(&nladdr, h, arg1); + if (err < 0) { + return err; + } + +skip_it: + h = NLMSG_NEXT(h, status); + } + if (msg.msg_flags & MSG_TRUNC) { + bb_error_msg("Message truncated"); + continue; + } + if (status) { + bb_error_msg_and_die("!!!Remnant of size %d", status); + } + } +} + +int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer, + unsigned groups, struct nlmsghdr *answer, + int (*junk)(struct sockaddr_nl *,struct nlmsghdr *n, void *), + void *jarg) +{ + int status; + unsigned seq; + struct nlmsghdr *h; + struct sockaddr_nl nladdr; + struct iovec iov = { (void*)n, n->nlmsg_len }; + char buf[8192]; + struct msghdr msg = { + (void*)&nladdr, sizeof(nladdr), + &iov, 1, + NULL, 0, + 0 + }; + + memset(&nladdr, 0, sizeof(nladdr)); + nladdr.nl_family = AF_NETLINK; + nladdr.nl_pid = peer; + nladdr.nl_groups = groups; + + n->nlmsg_seq = seq = ++rtnl->seq; + if (answer == NULL) { + n->nlmsg_flags |= NLM_F_ACK; + } + status = sendmsg(rtnl->fd, &msg, 0); + + if (status < 0) { + bb_perror_msg("Cannot talk to rtnetlink"); + return -1; + } + + iov.iov_base = buf; + + while (1) { + iov.iov_len = sizeof(buf); + status = recvmsg(rtnl->fd, &msg, 0); + + if (status < 0) { + if (errno == EINTR) { + continue; + } + bb_perror_msg("OVERRUN"); + continue; + } + if (status == 0) { + bb_error_msg("EOF on netlink"); + return -1; + } + if (msg.msg_namelen != sizeof(nladdr)) { + bb_error_msg_and_die("sender address length == %d", msg.msg_namelen); + } + for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) { + int l_err; + int len = h->nlmsg_len; + int l = len - sizeof(*h); + + if (l<0 || len>status) { + if (msg.msg_flags & MSG_TRUNC) { + bb_error_msg("Truncated message"); + return -1; + } + bb_error_msg_and_die("!!!malformed message: len=%d", len); + } + + if (nladdr.nl_pid != peer || + h->nlmsg_pid != rtnl->local.nl_pid || + h->nlmsg_seq != seq) { + if (junk) { + l_err = junk(&nladdr, h, jarg); + if (l_err < 0) { + return l_err; + } + } + continue; + } + + if (h->nlmsg_type == NLMSG_ERROR) { + struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h); + if (l < sizeof(struct nlmsgerr)) { + bb_error_msg("ERROR truncated"); + } else { + errno = -err->error; + if (errno == 0) { + if (answer) { + memcpy(answer, h, h->nlmsg_len); + } + return 0; + } + bb_perror_msg("RTNETLINK answers"); + } + return -1; + } + if (answer) { + memcpy(answer, h, h->nlmsg_len); + return 0; + } + + bb_error_msg("Unexpected reply!!!"); + + status -= NLMSG_ALIGN(len); + h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len)); + } + if (msg.msg_flags & MSG_TRUNC) { + bb_error_msg("Message truncated"); + continue; + } + if (status) { + bb_error_msg_and_die("!!!Remnant of size %d", status); + } + } +} + +int rtnl_listen(struct rtnl_handle *rtnl, + int (*handler)(struct sockaddr_nl *,struct nlmsghdr *n, void *), + void *jarg) +{ + int status; + struct nlmsghdr *h; + struct sockaddr_nl nladdr; + struct iovec iov; + char buf[8192]; + struct msghdr msg = { + (void*)&nladdr, sizeof(nladdr), + &iov, 1, + NULL, 0, + 0 + }; + + memset(&nladdr, 0, sizeof(nladdr)); + nladdr.nl_family = AF_NETLINK; + nladdr.nl_pid = 0; + nladdr.nl_groups = 0; + + + iov.iov_base = buf; + + while (1) { + iov.iov_len = sizeof(buf); + status = recvmsg(rtnl->fd, &msg, 0); + + if (status < 0) { + if (errno == EINTR) + continue; + bb_perror_msg("OVERRUN"); + continue; + } + if (status == 0) { + bb_error_msg("EOF on netlink"); + return -1; + } + if (msg.msg_namelen != sizeof(nladdr)) { + bb_error_msg_and_die("Sender address length == %d", msg.msg_namelen); + } + for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) { + int err; + int len = h->nlmsg_len; + int l = len - sizeof(*h); + + if (l<0 || len>status) { + if (msg.msg_flags & MSG_TRUNC) { + bb_error_msg("Truncated message"); + return -1; + } + bb_error_msg_and_die("!!!malformed message: len=%d", len); + } + + err = handler(&nladdr, h, jarg); + if (err < 0) { + return err; + } + + status -= NLMSG_ALIGN(len); + h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len)); + } + if (msg.msg_flags & MSG_TRUNC) { + bb_error_msg("Message truncated"); + continue; + } + if (status) { + bb_error_msg_and_die("!!!Remnant of size %d", status); + } + } +} + +int rtnl_from_file(FILE *rtnl, + int (*handler)(struct sockaddr_nl *,struct nlmsghdr *n, void *), + void *jarg) +{ + int status; + struct sockaddr_nl nladdr; + char buf[8192]; + struct nlmsghdr *h = (void*)buf; + + memset(&nladdr, 0, sizeof(nladdr)); + nladdr.nl_family = AF_NETLINK; + nladdr.nl_pid = 0; + nladdr.nl_groups = 0; + + while (1) { + int err, len, type; + int l; + + status = fread(&buf, 1, sizeof(*h), rtnl); + + if (status < 0) { + if (errno == EINTR) + continue; + bb_perror_msg("rtnl_from_file: fread"); + return -1; + } + if (status == 0) + return 0; + + len = h->nlmsg_len; + type= h->nlmsg_type; + l = len - sizeof(*h); + + if (l<0 || len>sizeof(buf)) { + bb_error_msg("!!!malformed message: len=%d @%lu", + len, ftell(rtnl)); + return -1; + } + + status = fread(NLMSG_DATA(h), 1, NLMSG_ALIGN(l), rtnl); + + if (status < 0) { + bb_perror_msg("rtnl_from_file: fread"); + return -1; + } + if (status < l) { + bb_error_msg("rtnl-from_file: truncated message"); + return -1; + } + + err = handler(&nladdr, h, jarg); + if (err < 0) + return err; + } +} + +int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data) +{ + int len = RTA_LENGTH(4); + struct rtattr *rta; + if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen) + return -1; + rta = (struct rtattr*)(((char*)n) + NLMSG_ALIGN(n->nlmsg_len)); + rta->rta_type = type; + rta->rta_len = len; + memcpy(RTA_DATA(rta), &data, 4); + n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len; + return 0; +} + +int addattr_l(struct nlmsghdr *n, int maxlen, int type, void *data, int alen) +{ + int len = RTA_LENGTH(alen); + struct rtattr *rta; + + if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen) + return -1; + rta = (struct rtattr*)(((char*)n) + NLMSG_ALIGN(n->nlmsg_len)); + rta->rta_type = type; + rta->rta_len = len; + memcpy(RTA_DATA(rta), data, alen); + n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len; + return 0; +} + +int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data) +{ + int len = RTA_LENGTH(4); + struct rtattr *subrta; + + if (RTA_ALIGN(rta->rta_len) + len > maxlen) { + return -1; + } + subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len)); + subrta->rta_type = type; + subrta->rta_len = len; + memcpy(RTA_DATA(subrta), &data, 4); + rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len; + return 0; +} + +int rta_addattr_l(struct rtattr *rta, int maxlen, int type, void *data, int alen) +{ + struct rtattr *subrta; + int len = RTA_LENGTH(alen); + + if (RTA_ALIGN(rta->rta_len) + len > maxlen) { + return -1; + } + subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len)); + subrta->rta_type = type; + subrta->rta_len = len; + memcpy(RTA_DATA(subrta), data, alen); + rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len; + return 0; +} + + +int 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) { + bb_error_msg("!!!Deficit %d, rta_len=%d", len, rta->rta_len); + } + return 0; +} |