/*
* 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 <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <unistd.h>
#include <fcntl.h>
#include <net/if_arp.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <errno.h>
#include <time.h>
#include <sys/uio.h>
#include <linux/fib_rules.h>
#include <linux/if_addrlabel.h>
#include <linux/if_bridge.h>
#include <linux/nexthop.h>
#include "libnetlink.h"
#include "utils.h"
#ifndef __aligned
#define __aligned(x) __attribute__((aligned(x)))
#endif
#ifndef SOL_NETLINK
#define SOL_NETLINK 270
#endif
#ifndef MIN
#define MIN(a, b) ((a) < (b) ? (a) : (b))
#endif
int rcvbuf = 1024 * 1024;
#ifdef HAVE_LIBMNL
#include <libmnl/libmnl.h>
static const enum mnl_attr_data_type extack_policy[NLMSGERR_ATTR_MAX + 1] = {
[NLMSGERR_ATTR_MSG] = MNL_TYPE_NUL_STRING,
[NLMSGERR_ATTR_OFFS] = MNL_TYPE_U32,
};
static int err_attr_cb(const struct nlattr *attr, void *data)
{
const struct nlattr **tb = data;
uint16_t type;
if (mnl_attr_type_valid(attr, NLMSGERR_ATTR_MAX) < 0) {
fprintf(stderr, "Invalid extack attribute\n");
return MNL_CB_ERROR;
}
type = mnl_attr_get_type(attr);
if (mnl_attr_validate(attr, extack_policy[type]) < 0) {
fprintf(stderr, "extack attribute %d failed validation\n",
type);
return MNL_CB_ERROR;
}
tb[type] = attr;
return MNL_CB_OK;
}
static void print_ext_ack_msg(bool is_err, const char *msg)
{
fprintf(stderr, "%s: %s", is_err ? "Error" : "Warning", msg);
if (msg[strlen(msg) - 1] != '.')
fprintf(stderr, ".");
fprintf(stderr, "\n");
}
/* dump netlink extended ack error message */
int nl_dump_ext_ack(const struct nlmsghdr *nlh, nl_ext_ack_fn_t errfn)
{
struct nlattr *tb[NLMSGERR_ATTR_MAX + 1] = {};
const struct nlmsgerr *err = mnl_nlmsg_get_payload(nlh);
const struct nlmsghdr *err_nlh = NULL;
unsigned int hlen = sizeof(*err);
const char *msg = NULL;
uint32_t off = 0;
/* no TLVs, nothing to do here */
if (!(nlh->nlmsg_flags & NLM_F_ACK_TLVS))
return 0;
/* if NLM_F_CAPPED is set then the inner err msg was capped */
if (!(nlh->nlmsg_flags & NLM_F_CAPPED))
hlen += mnl_nlmsg_get_payload_len(&err->msg);
if (mnl_attr_parse(nlh, hlen, err_attr_cb, tb) != MNL_CB_OK)
return 0;
if (tb[NLMSGERR_ATTR_MSG])
msg = mnl_attr_get_str(tb[NLMSGERR_ATTR_MSG]);
if (tb[NLMSGERR_ATTR_OFFS]) {
off = mnl_attr_get_u32(tb[NLMSGERR_ATTR_OFFS]);
if (off > nlh->nlmsg_len) {
fprintf(stderr,
"Invalid offset for NLMSGERR_ATTR_OFFS\n");
off = 0;
} else if (!(nlh->nlmsg_flags & NLM_F_CAPPED))
err_nlh = &err->msg;
}
if (errfn)
return errfn(msg, off, err_nlh);
if (msg && *msg != '\0') {
bool is_err = !!err->error;
print_ext_ack_msg(is_err, msg);
return is_err ? 1 : 0;
}
return 0;
}
int nl_dump_ext_ack_done(const struct nlmsghdr *nlh, int error)
{
struct nlattr *tb[NLMSGERR_ATTR_MAX + 1] = {};
unsigned int hlen = sizeof(int);
const char *msg = NULL;
if (mnl_attr_parse(nlh, hlen, err_attr_cb, tb) != MNL_CB_OK)
return 0;
if (tb[NLMSGERR_ATTR_MSG])
msg = mnl_attr_get_str(tb[NLMSGERR_ATTR_MSG]);
if (msg && *msg != '\0') {
bool is_err = !!error;
print_ext_ack_msg(is_err, msg);
return is_err ? 1 : 0;
}
return 0;
}
#else
#warning "libmnl required for error support"
/* No extended error ack without libmnl */
int nl_dump_ext_ack(const struct nlmsghdr *nlh, nl_ext_ack_fn_t errfn)
{
return 0;
}
int nl_dump_ext_ack_done(const struct nlmsghdr *nlh, int error)
{
return 0;
}
#endif
/* Older kernels may not support strict dump and filtering */
void rtnl_set_strict_dump(struct rtnl_handle *rth)
{
int one = 1;
if (setsockopt(rth->fd, SOL_NETLINK, NETLINK_GET_STRICT_CHK,
&one, sizeof(one)) < 0)
return;
rth->flags |= RTNL_HANDLE_F_STRICT_CHK;
}
int rtnl_add_nl_group(struct rtnl_handle *rth, unsigned int group)
{
return setsockopt(rth->fd, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP,
&group, sizeof(group));
}
void rtnl_close(struct rtnl_handle *rth)
{
if (rth->fd >= 0) {
close(rth->fd);
rth->fd = -1;
}
}
int rtnl_open_byproto(struct rtnl_handle *rth, unsigned int subscriptions,
int protocol)
{
socklen_t addr_len;
int sndbuf = 32768;
int one = 1;
memset(rth, 0, sizeof(*rth));
rth->proto = protocol;
rth->fd = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, protocol);
if (rth->fd < 0) {
perror("Cannot open netlink socket");
return -1;
}
if (setsockopt(rth->fd, SOL_SOCKET, SO_SNDBUF,
&sndbuf, sizeof(sndbuf)) < 0) {
perror("SO_SNDBUF");
return -1;
}
if (setsockopt(rth->fd, SOL_SOCKET, SO_RCVBUF,
&rcvbuf, sizeof(rcvbuf)) < 0) {
perror("SO_RCVBUF");
return -1;
}
/* Older kernels may no support extended ACK reporting */
setsockopt(rth->fd, SOL_NETLINK, NETLINK_EXT_ACK,
&one, sizeof(one));
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) {
perror("Cannot bind netlink socket");
return -1;
}
addr_len = sizeof(rth->local);
if (getsockname(rth->fd, (struct sockaddr *)&rth->local,
&addr_len) < 0) {
perror("Cannot getsockname");
return -1;
}
if (addr_len != sizeof(rth->local)) {
fprintf(stderr, "Wrong address length %d\n", addr_len);
return -1;
}
if (rth->local.nl_family != AF_NETLINK) {
fprintf(stderr, "Wrong address family %d\n",
rth->local.nl_family);
return -1;
}
rth->seq = time(NULL);
return 0;
}
int rtnl_open(struct rtnl_handle *rth, unsigned int subscriptions)
{
return rtnl_open_byproto(rth, subscriptions, NETLINK_ROUTE);
}
int rtnl_nexthopdump_req(struct rtnl_handle *rth, int family,
req_filter_fn_t filter_fn)
{
struct {
struct nlmsghdr nlh;
struct nhmsg nhm;
char buf[128];
} req = {
.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct nhmsg)),
.nlh.nlmsg_type = RTM_GETNEXTHOP,
.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
.nlh.nlmsg_seq = rth->dump = ++rth->seq,
.nhm.nh_family = family,
};
if (filter_fn) {
int err;
err = filter_fn(&req.nlh, sizeof(req));
if (err)
return err;
}
return send(rth->fd, &req, sizeof(req), 0);
}
int rtnl_addrdump_req(struct rtnl_handle *rth, int family,
req_filter_fn_t filter_fn)
{
struct {
struct nlmsghdr nlh;
struct ifaddrmsg ifm;
char buf[128];
} req = {
.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg)),
.nlh.nlmsg_type = RTM_GETADDR,
.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
.nlh.nlmsg_seq = rth->dump = ++rth->seq,
.ifm.ifa_family = family,
};
if (filter_fn) {
int err;
err = filter_fn(&req.nlh, sizeof(req));
if (err)
return err;
}
return send(rth->fd, &req, sizeof(req), 0);
}
int rtnl_addrlbldump_req(struct rtnl_handle *rth, int family)
{
struct {
struct nlmsghdr nlh;
struct ifaddrlblmsg ifal;
} req = {
.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrlblmsg)),
.nlh.nlmsg_type = RTM_GETADDRLABEL,
.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
.nlh.nlmsg_seq = rth->dump = ++rth->seq,
.ifal.ifal_family = family,
};
return send(rth->fd, &req, sizeof(req), 0);
}
int rtnl_routedump_req(struct rtnl_handle *rth, int family,
req_filter_fn_t filter_fn)
{
struct {
struct nlmsghdr nlh;
struct rtmsg rtm;
char buf[128];
} req = {
.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg)),
.nlh.nlmsg_type = RTM_GETROUTE,
.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
.nlh.nlmsg_seq = rth->dump = ++rth->seq,
.rtm.rtm_family = family,
};
if (filter_fn) {
int err;
err = filter_fn(&req.nlh, sizeof(req));
if (err)
return err;
}
return send(rth->fd, &req, sizeof(req), 0);
}
int rtnl_ruledump_req(struct rtnl_handle *rth, int family)
{
struct {
struct nlmsghdr nlh;
struct fib_rule_hdr frh;
} req = {
.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct fib_rule_hdr)),
.nlh.nlmsg_type = RTM_GETRULE,
.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
.nlh.nlmsg_seq = rth->dump = ++rth->seq,
.frh.family = family
};
return send(rth->fd, &req, sizeof(req), 0);
}
int rtnl_neighdump_req(struct rtnl_handle *rth, int family,
req_filter_fn_t filter_fn)
{
struct {
struct nlmsghdr nlh;
struct ndmsg ndm;
char buf[256];
} req = {
.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndmsg)),
.nlh.nlmsg_type = RTM_GETNEIGH,
.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
.nlh.nlmsg_seq = rth->dump = ++rth->seq,
.ndm.ndm_family = family,
};
if (filter_fn) {
int err;
err = filter_fn(&req.nlh, sizeof(req));
if (err)
return err;
}
return send(rth->fd, &req, sizeof(req), 0);
}
int rtnl_neightbldump_req(struct rtnl_handle *rth, int family)
{
struct {
struct nlmsghdr nlh;
struct ndtmsg ndtmsg;
} req = {
.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndtmsg)),
.nlh.nlmsg_type = RTM_GETNEIGHTBL,
.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
.nlh.nlmsg_seq = rth->dump = ++rth->seq,
.ndtmsg.ndtm_family = family,
};
return send(rth->fd, &req, sizeof(req), 0);
}
int rtnl_mdbdump_req(struct rtnl_handle *rth, int family)
{
struct {
struct nlmsghdr nlh;
struct br_port_msg bpm;
} req = {
.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct br_port_msg)),
.nlh.nlmsg_type = RTM_GETMDB,
.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
.nlh.nlmsg_seq = rth->dump = ++rth->seq,
.bpm.family = family,
};
return send(rth->fd, &req, sizeof(req), 0);
}
int rtnl_netconfdump_req(struct rtnl_handle *rth, int family)
{
struct {
struct nlmsghdr nlh;
struct netconfmsg ncm;
char buf[0] __aligned(NLMSG_ALIGNTO);
} req = {
.nlh.nlmsg_len = NLMSG_LENGTH(NLMSG_ALIGN(sizeof(struct netconfmsg))),
.nlh.nlmsg_type = RTM_GETNETCONF,
.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
.nlh.nlmsg_seq = rth->dump = ++rth->seq,
.ncm.ncm_family = family,
};
return send(rth->fd, &req, sizeof(req), 0);
}
int rtnl_nsiddump_req_filter_fn(struct rtnl_handle *rth, int family,
req_filter_fn_t filter_fn)
{
struct {
struct nlmsghdr nlh;
struct rtgenmsg rtm;
char buf[1024];
} req = {
.nlh.nlmsg_len = NLMSG_LENGTH(NLMSG_ALIGN(sizeof(struct rtgenmsg))),
.nlh.nlmsg_type = RTM_GETNSID,
.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
.nlh.nlmsg_seq = rth->dump = ++rth->seq,
.rtm.rtgen_family = family,
};
int err;
if (!filter_fn)
return -EINVAL;
err = filter_fn(&req.nlh, sizeof(req));
if (err)
return err;
return send(rth->fd, &req, req.nlh.nlmsg_len, 0);
}
static int __rtnl_linkdump_req(struct rtnl_handle *rth, int family)
{
struct {
struct nlmsghdr nlh;
struct ifinfomsg ifm;
} req = {
.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
.nlh.nlmsg_type = RTM_GETLINK,
.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
.nlh.nlmsg_seq = rth->dump = ++rth->seq,
.ifm.ifi_family = family,
};
return send(rth->fd, &req, sizeof(req), 0);
}
int rtnl_linkdump_req(struct rtnl_handle *rth, int family)
{
if (family == AF_UNSPEC)
return rtnl_linkdump_req_filter(rth, family, RTEXT_FILTER_VF);
return __rtnl_linkdump_req(rth, family);
}
int rtnl_linkdump_req_filter(struct rtnl_handle *rth, int family,
__u32 filt_mask)
{
if (family == AF_UNSPEC || family == AF_BRIDGE) {
struct {
struct nlmsghdr nlh;
struct ifinfomsg ifm;
/* attribute has to be NLMSG aligned */
struct rtattr ext_req __aligned(NLMSG_ALIGNTO);
__u32 ext_filter_mask;
} req = {
.nlh.nlmsg_len = sizeof(req),
.nlh.nlmsg_type = RTM_GETLINK,
.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
.nlh.nlmsg_seq = rth->dump = ++rth->seq,
.ifm.ifi_family = family,
.ext_req.rta_type = IFLA_EXT_MASK,
.ext_req.rta_len = RTA_LENGTH(sizeof(__u32)),
.ext_filter_mask = filt_mask,
};
return send(rth->fd, &req, sizeof(req), 0);
}
return __rtnl_linkdump_req(rth, family);
}
int rtnl_linkdump_req_filter_fn(struct rtnl_handle *rth, int family,
req_filter_fn_t filter_fn)
{
if (family == AF_UNSPEC || family == AF_PACKET) {
struct {
struct nlmsghdr nlh;
struct ifinfomsg ifm;
char buf[1024];
} req = {
.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
.nlh.nlmsg_type = RTM_GETLINK,
.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
.nlh.nlmsg_seq = rth->dump = ++rth->seq,
.ifm.ifi_family = family,
};
int err;
if (!filter_fn)
return -EINVAL;
err = filter_fn(&req.nlh, sizeof(req));
if (err)
return err;
return send(rth->fd, &req, req.nlh.nlmsg_len, 0);
}
return __rtnl_linkdump_req(rth, family);
}
int rtnl_fdb_linkdump_req_filter_fn(struct rtnl_handle *rth,
req_filter_fn_t filter_fn)
{
struct {
struct nlmsghdr nlh;
struct ifinfomsg ifm;
char buf[128];
} req = {
.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
.nlh.nlmsg_type = RTM_GETNEIGH,
.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
.nlh.nlmsg_seq = rth->dump = ++rth->seq,
.ifm.ifi_family = PF_BRIDGE,
};
int err;
err = filter_fn(&req.nlh, sizeof(req));
if (err)
return err;
return send(rth->fd, &req, sizeof(req), 0);
}
int rtnl_statsdump_req_filter(struct rtnl_handle *rth, int fam, __u32 filt_mask)
{
struct {
struct nlmsghdr nlh;
struct if_stats_msg ifsm;
} req;
memset(&req, 0, sizeof(req));
req.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct if_stats_msg));
req.nlh.nlmsg_type = RTM_GETSTATS;
req.nlh.nlmsg_flags = NLM_F_DUMP|NLM_F_REQUEST;
req.nlh.nlmsg_pid = 0;
req.nlh.nlmsg_seq = rth->dump = ++rth->seq;
req.ifsm.family = fam;
req.ifsm.filter_mask = filt_mask;
return send(rth->fd, &req, sizeof(req), 0);
}
int rtnl_send(struct rtnl_handle *rth, const void *buf, int len)
{
return send(rth->fd, buf, len, 0);
}
int rtnl_send_check(struct rtnl_handle *rth, const void *buf, int len)
{
struct nlmsghdr *h;
int status;
char resp[1024];
status = send(rth->fd, buf, len, 0);
if (status < 0)
return status;
/* Check for immediate errors */
status = recv(rth->fd, resp, sizeof(resp), MSG_DONTWAIT|MSG_PEEK);
if (status < 0) {
if (errno == EAGAIN)
return 0;
return -1;
}
for (h = (struct nlmsghdr *)resp; NLMSG_OK(h, status);
h = NLMSG_NEXT(h, status)) {
if (h->nlmsg_type == NLMSG_ERROR) {
struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(h);
if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr)))
fprintf(stderr, "ERROR truncated\n");
else
errno = -err->error;
return -1;
}
}
return 0;
}
int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len)
{
struct nlmsghdr nlh = {
.nlmsg_len = NLMSG_LENGTH(len),
.nlmsg_type = type,
.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
.nlmsg_seq = rth->dump = ++rth->seq,
};
struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
struct iovec iov[2] = {
{ .iov_base = &nlh, .iov_len = sizeof(nlh) },
{ .iov_base = req, .iov_len = len }
};
struct msghdr msg = {
.msg_name = &nladdr,
.msg_namelen = sizeof(nladdr),
.msg_iov = iov,
.msg_iovlen = 2,
};
return sendmsg(rth->fd, &msg, 0);
}
int rtnl_dump_request_n(struct rtnl_handle *rth, struct nlmsghdr *n)
{
struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
struct iovec iov = {
.iov_base = n,
.iov_len = n->nlmsg_len
};
struct msghdr msg = {
.msg_name = &nladdr,
.msg_namelen = sizeof(nladdr),
.msg_iov = &iov,
.msg_iovlen = 1,
};
n->nlmsg_flags = NLM_F_DUMP|NLM_F_REQUEST;
n->nlmsg_pid = 0;
n->nlmsg_seq = rth->dump = ++rth->seq;
return sendmsg(rth->fd, &msg, 0);
}
static int rtnl_dump_done(struct nlmsghdr *h)
{
int len = *(int *)NLMSG_DATA(h);
if (h->nlmsg_len < NLMSG_LENGTH(sizeof(int))) {
fprintf(stderr, "DONE truncated\n");
return -1;
}
if (len < 0) {
/* check for any messages returned from kernel */
if (nl_dump_ext_ack_done(h, len))
return len;
errno = -len;
switch (errno) {
case ENOENT:
case EOPNOTSUPP:
return -1;
case EMSGSIZE:
fprintf(stderr,
"Error: Buffer too small for object.\n");
break;
default:
perror("RTNETLINK answers");
}
return len;
}
/* check for any messages returned from kernel */
nl_dump_ext_ack(h, NULL);
return 0;
}
static void rtnl_dump_error(const struct rtnl_handle *rth,
struct nlmsghdr *h)
{
if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
fprintf(stderr, "ERROR truncated\n");
} else {
const struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(h);
errno = -err->error;
if (rth->proto == NETLINK_SOCK_DIAG &&
(errno == ENOENT ||
errno == EOPNOTSUPP))
return;
if (!(rth->flags & RTNL_HANDLE_F_SUPPRESS_NLERR))
perror("RTNETLINK answers");
}
}
static int __rtnl_recvmsg(int fd, struct msghdr *msg, int flags)
{
int len;
do {
len = recvmsg(fd, msg, flags);
} while (len < 0 && (errno == EINTR || errno == EAGAIN));
if (len < 0) {
fprintf(stderr, "netlink receive error %s (%d)\n",
strerror(errno), errno);
return -errno;
}
if (len == 0) {
fprintf(stderr, "EOF on netlink\n");
return -ENODATA;
}
return len;
}
static int rtnl_recvmsg(int fd, struct msghdr *msg, char **answer)
{
struct iovec *iov = msg->msg_iov;
char *buf;
int len;
iov->iov_base = NULL;
iov->iov_len = 0;
len = __rtnl_recvmsg(fd, msg, MSG_PEEK | MSG_TRUNC);
if (len < 0)
return len;
if (len < 32768)
len = 32768;
buf = malloc(len);
if (!buf) {
fprintf(stderr, "malloc error: not enough buffer\n");
return -ENOMEM;
}
iov->iov_base = buf;
iov->iov_len = len;
len = __rtnl_recvmsg(fd, msg, 0);
if (len < 0) {
free(buf);
return len;
}
if (answer)
*answer = buf;
else
free(buf);
return len;
}
static int rtnl_dump_filter_l(struct rtnl_handle *rth,
const struct rtnl_dump_filter_arg *arg)
{
struct sockaddr_nl nladdr;
struct iovec iov;
struct msghdr msg = {
.msg_name = &nladdr,
.msg_namelen = sizeof(nladdr),
.msg_iov = &iov,
.msg_iovlen = 1,
};
char *buf;
int dump_intr = 0;
while (1) {
int status;
const struct rtnl_dump_filter_arg *a;
int found_done = 0;
int msglen = 0;
status = rtnl_recvmsg(rth->fd, &msg, &buf);
if (status < 0)
return status;
if (rth->dump_fp)
fwrite(buf, 1, NLMSG_ALIGN(status), rth->dump_fp);
for (a = arg; a->filter; a++) {
struct nlmsghdr *h = (struct nlmsghdr *)buf;
msglen = status;
while (NLMSG_OK(h, msglen)) {
int err = 0;
h->nlmsg_flags &= ~a->nc_flags;
if (nladdr.nl_pid != 0 ||
h->nlmsg_pid != rth->local.nl_pid ||
h->nlmsg_seq != rth->dump)
goto skip_it;
if (h->nlmsg_flags & NLM_F_DUMP_INTR)
dump_intr = 1;
if (h->nlmsg_type == NLMSG_DONE) {
err = rtnl_dump_done(h);
if (err < 0) {
free(buf);
return -1;
}
found_done = 1;
break; /* process next filter */
}
if (h->nlmsg_type == NLMSG_ERROR) {
rtnl_dump_error(rth, h);
free(buf);
return -1;
}
if (!rth->dump_fp) {
err = a->filter(h, a->arg1);
if (err < 0) {
free(buf);
return err;
}
}
skip_it:
h = NLMSG_NEXT(h, msglen);
}
}
free(buf);
if (found_done) {
if (dump_intr)
fprintf(stderr,
"Dump was interrupted and may be inconsistent.\n");
return 0;
}
if (msg.msg_flags & MSG_TRUNC) {
fprintf(stderr, "Message truncated\n");
continue;
}
if (msglen) {
fprintf(stderr, "!!!Remnant of size %d\n", msglen);
exit(1);
}
}
}
int rtnl_dump_filter_nc(struct rtnl_handle *rth,
rtnl_filter_t filter,
void *arg1, __u16 nc_flags)
{
const struct rtnl_dump_filter_arg a[2] = {
{ .filter = filter, .arg1 = arg1, .nc_flags = nc_flags, },
{ .filter = NULL, .arg1 = NULL, .nc_flags = 0, },
};
return rtnl_dump_filter_l(rth, a);
}
static void rtnl_talk_error(struct nlmsghdr *h, struct nlmsgerr *err,
nl_ext_ack_fn_t errfn)
{
if (nl_dump_ext_ack(h, errfn))
return;
fprintf(stderr, "RTNETLINK answers: %s\n",
strerror(-err->error));
}
static int __rtnl_talk_iov(struct rtnl_handle *rtnl, struct iovec *iov,
size_t iovlen, struct nlmsghdr **answer,
bool show_rtnl_err, nl_ext_ack_fn_t errfn)
{
struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
struct iovec riov;
struct msghdr msg = {
.msg_name = &nladdr,
.msg_namelen = sizeof(nladdr),
.msg_iov = iov,
.msg_iovlen = iovlen,
};
unsigned int seq = 0;
struct nlmsghdr *h;
int i, status;
char *buf;
for (i = 0; i < iovlen; i++) {
h = iov[i].iov_base;
h->nlmsg_seq = seq = ++rtnl->seq;
if (answer == NULL)
h->nlmsg_flags |= NLM_F_ACK;
}
status = sendmsg(rtnl->fd, &msg, 0);
if (status < 0) {
perror("Cannot talk to rtnetlink");
return -1;
}
/* change msg to use the response iov */
msg.msg_iov = &riov;
msg.msg_iovlen = 1;
i = 0;
while (1) {
next:
status = rtnl_recvmsg(rtnl->fd, &msg, &buf);
++i;
if (status < 0)
return status;
if (msg.msg_namelen != sizeof(nladdr)) {
fprintf(stderr,
"sender address length == %d\n",
msg.msg_namelen);
exit(1);
}
for (h = (struct nlmsghdr *)buf; status >= sizeof(*h); ) {
int len = h->nlmsg_len;
int l = len - sizeof(*h);
if (l < 0 || len > status) {
if (msg.msg_flags & MSG_TRUNC) {
fprintf(stderr, "Truncated message\n");
free(buf);
return -1;
}
fprintf(stderr,
"!!!malformed message: len=%d\n",
len);
exit(1);
}
if (nladdr.nl_pid != 0 ||
h->nlmsg_pid != rtnl->local.nl_pid ||
h->nlmsg_seq > seq || h->nlmsg_seq < seq - iovlen) {
/* Don't forget to skip that message. */
status -= NLMSG_ALIGN(len);
h = (struct nlmsghdr *)((char *)h + NLMSG_ALIGN(len));
continue;
}
if (h->nlmsg_type == NLMSG_ERROR) {
struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(h);
int error = err->error;
if (l < sizeof(struct nlmsgerr)) {
fprintf(stderr, "ERROR truncated\n");
free(buf);
return -1;
}
if (!error) {
/* check messages from kernel */
nl_dump_ext_ack(h, errfn);
} else {
errno = -error;
if (rtnl->proto != NETLINK_SOCK_DIAG &&
show_rtnl_err)
rtnl_talk_error(h, err, errfn);
}
if (answer)
*answer = (struct nlmsghdr *)buf;
else
free(buf);
if (i < iovlen)
goto next;
return error ? -i : 0;
}
if (answer) {
*answer = (struct nlmsghdr *)buf;
return 0;
}
fprintf(stderr, "Unexpected reply!!!\n");
status -= NLMSG_ALIGN(len);
h = (struct nlmsghdr *)((char *)h + NLMSG_ALIGN(len));
}
free(buf);
if (msg.msg_flags & MSG_TRUNC) {
fprintf(stderr, "Message truncated\n");
continue;
}
if (status) {
fprintf(stderr, "!!!Remnant of size %d\n", status);
exit(1);
}
}
}
static int __rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
struct nlmsghdr **answer,
bool show_rtnl_err, nl_ext_ack_fn_t errfn)
{
struct iovec iov = {
.iov_base = n,
.iov_len = n->nlmsg_len
};
return __rtnl_talk_iov(rtnl, &iov, 1, answer, show_rtnl_err, errfn);
}
int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
struct nlmsghdr **answer)
{
return __rtnl_talk(rtnl, n, answer, true, NULL);
}
int rtnl_talk_iov(struct rtnl_handle *rtnl, struct iovec *iovec, size_t iovlen,
struct nlmsghdr **answer)
{
return __rtnl_talk_iov(rtnl, iovec, iovlen, answer, true, NULL);
}
int rtnl_talk_suppress_rtnl_errmsg(struct rtnl_handle *rtnl, struct nlmsghdr *n,
struct nlmsghdr **answer)
{
return __rtnl_talk(rtnl, n, answer, false, NULL);
}
int rtnl_listen_all_nsid(struct rtnl_handle *rth)
{
unsigned int on = 1;
if (setsockopt(rth->fd, SOL_NETLINK, NETLINK_LISTEN_ALL_NSID, &on,
sizeof(on)) < 0) {
perror("NETLINK_LISTEN_ALL_NSID");
return -1;
}
rth->flags |= RTNL_HANDLE_F_LISTEN_ALL_NSID;
return 0;
}
int rtnl_listen(struct rtnl_handle *rtnl,
rtnl_listen_filter_t handler,
void *jarg)
{
int status;
struct nlmsghdr *h;
struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
struct iovec iov;
struct msghdr msg = {
.msg_name = &nladdr,
.msg_namelen = sizeof(nladdr),
.msg_iov = &iov,
.msg_iovlen = 1,
};
char buf[16384];
char cmsgbuf[BUFSIZ];
if (rtnl->flags & RTNL_HANDLE_F_LISTEN_ALL_NSID) {
msg.msg_control = &cmsgbuf;
msg.msg_controllen = sizeof(cmsgbuf);
}
iov.iov_base = buf;
while (1) {
struct rtnl_ctrl_data ctrl;
struct cmsghdr *cmsg;
iov.iov_len = sizeof(buf);
status = recvmsg(rtnl->fd, &msg, 0);
if (status < 0) {
if (errno == EINTR || errno == EAGAIN)
continue;
fprintf(stderr, "netlink receive error %s (%d)\n",
strerror(errno), errno);
if (errno == ENOBUFS)
continue;
return -1;
}
if (status == 0) {
fprintf(stderr, "EOF on netlink\n");
return -1;
}
if (msg.msg_namelen != sizeof(nladdr)) {
fprintf(stderr,
"Sender address length == %d\n",
msg.msg_namelen);
exit(1);
}
if (rtnl->flags & RTNL_HANDLE_F_LISTEN_ALL_NSID) {
memset(&ctrl, 0, sizeof(ctrl));
ctrl.nsid = -1;
for (cmsg = CMSG_FIRSTHDR(&msg); cmsg;
cmsg = CMSG_NXTHDR(&msg, cmsg))
if (cmsg->cmsg_level == SOL_NETLINK &&
cmsg->cmsg_type == NETLINK_LISTEN_ALL_NSID &&
cmsg->cmsg_len == CMSG_LEN(sizeof(int))) {
int *data = (int *)CMSG_DATA(cmsg);
ctrl.nsid = *data;
}
}
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) {
fprintf(stderr, "Truncated message\n");
return -1;
}
fprintf(stderr,
"!!!malformed message: len=%d\n",
len);
exit(1);
}
err = handler(&ctrl, 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) {
fprintf(stderr, "Message truncated\n");
continue;
}
if (status) {
fprintf(stderr, "!!!Remnant of size %d\n", status);
exit(1);
}
}
}
int rtnl_from_file(FILE *rtnl, rtnl_listen_filter_t handler,
void *jarg)
{
size_t status;
char buf[16384];
struct nlmsghdr *h = (struct nlmsghdr *)buf;
while (1) {
int err, len;
int l;
status = fread(&buf, 1, sizeof(*h), rtnl);
if (status == 0 && feof(rtnl))
return 0;
if (status != sizeof(*h)) {
if (ferror(rtnl))
perror("rtnl_from_file: fread");
if (feof(rtnl))
fprintf(stderr, "rtnl-from_file: truncated message\n");
return -1;
}
len = h->nlmsg_len;
l = len - sizeof(*h);
if (l < 0 || len > sizeof(buf)) {
fprintf(stderr, "!!!malformed message: len=%d @%lu\n",
len, ftell(rtnl));
return -1;
}
status = fread(NLMSG_DATA(h), 1, NLMSG_ALIGN(l), rtnl);
if (status != NLMSG_ALIGN(l)) {
if (ferror(rtnl))
perror("rtnl_from_file: fread");
if (feof(rtnl))
fprintf(stderr, "rtnl-from_file: truncated message\n");
return -1;
}
err = handler(NULL, h, jarg);
if (err < 0)
return err;
}
}
int addattr(struct nlmsghdr *n, int maxlen, int type)
{
return addattr_l(n, maxlen, type, NULL, 0);
}
int addattr8(struct nlmsghdr *n, int maxlen, int type, __u8 data)
{
return addattr_l(n, maxlen, type, &data, sizeof(__u8));
}
int addattr16(struct nlmsghdr *n, int maxlen, int type, __u16 data)
{
return addattr_l(n, maxlen, type, &data, sizeof(__u16));
}
int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data)
{
return addattr_l(n, maxlen, type, &data, sizeof(__u32));
}
int addattr64(struct nlmsghdr *n, int maxlen, int type, __u64 data)
{
return addattr_l(n, maxlen, type, &data, sizeof(__u64));
}
int addattrstrz(struct nlmsghdr *n, int maxlen, int type, const char *str)
{
return addattr_l(n, maxlen, type, str, strlen(str)+1);
}
int addattr_l(struct nlmsghdr *n, int maxlen, int type, const void *data,
int alen)
{
int len = RTA_LENGTH(alen);
struct rtattr *rta;
if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen) {
fprintf(stderr,
"addattr_l ERROR: message exceeded bound of %d\n",
maxlen);
return -1;
}
rta = NLMSG_TAIL(n);
rta->rta_type = type;
rta->rta_len = len;
if (alen)
memcpy(RTA_DATA(rta), data, alen);
n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len);
return 0;
}
int addraw_l(struct nlmsghdr *n, int maxlen, const void *data, int len)
{
if (NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len) > maxlen) {
fprintf(stderr,
"addraw_l ERROR: message exceeded bound of %d\n",
maxlen);
return -1;
}
memcpy(NLMSG_TAIL(n), data, len);
memset((void *) NLMSG_TAIL(n) + len, 0, NLMSG_ALIGN(len) - len);
n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len);
return 0;
}
struct rtattr *addattr_nest(struct nlmsghdr *n, int maxlen, int type)
{
struct rtattr *nest = NLMSG_TAIL(n);
addattr_l(n, maxlen, type, NULL, 0);
return nest;
}
int addattr_nest_end(struct nlmsghdr *n, struct rtattr *nest)
{
nest->rta_len = (void *)NLMSG_TAIL(n) - (void *)nest;
return n->nlmsg_len;
}
struct rtattr *addattr_nest_compat(struct nlmsghdr *n, int maxlen, int type,
const void *data, int len)
{
struct rtattr *start = NLMSG_TAIL(n);
addattr_l(n, maxlen, type, data, len);
addattr_nest(n, maxlen, type);
return start;
}
int addattr_nest_compat_end(struct nlmsghdr *n, struct rtattr *start)
{
struct rtattr *nest = (void *)start + NLMSG_ALIGN(start->rta_len);
start->rta_len = (void *)NLMSG_TAIL(n) - (void *)start;
addattr_nest_end(n, nest);
return n->nlmsg_len;
}
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) {
fprintf(stderr,
"rta_addattr32: Error! max allowed bound %d exceeded\n",
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,
const void *data, int alen)
{
struct rtattr *subrta;
int len = RTA_LENGTH(alen);
if (RTA_ALIGN(rta->rta_len) + RTA_ALIGN(len) > maxlen) {
fprintf(stderr,
"rta_addattr_l: Error! max allowed bound %d exceeded\n",
maxlen);
return -1;
}
subrta = (struct rtattr *)(((char *)rta) + RTA_ALIGN(rta->rta_len));
subrta->rta_type = type;
subrta->rta_len = len;
if (alen)
memcpy(RTA_DATA(subrta), data, alen);
rta->rta_len = NLMSG_ALIGN(rta->rta_len) + RTA_ALIGN(len);
return 0;
}
int rta_addattr8(struct rtattr *rta, int maxlen, int type, __u8 data)
{
return rta_addattr_l(rta, maxlen, type, &data, sizeof(__u8));
}
int rta_addattr16(struct rtattr *rta, int maxlen, int type, __u16 data)
{
return rta_addattr_l(rta, maxlen, type, &data, sizeof(__u16));
}
int rta_addattr64(struct rtattr *rta, int maxlen, int type, __u64 data)
{
return rta_addattr_l(rta, maxlen, type, &data, sizeof(__u64));
}
struct rtattr *rta_nest(struct rtattr *rta, int maxlen, int type)
{
struct rtattr *nest = RTA_TAIL(rta);
rta_addattr_l(rta, maxlen, type, NULL, 0);
nest->rta_type |= NLA_F_NESTED;
return nest;
}
int rta_nest_end(struct rtattr *rta, struct rtattr *nest)
{
nest->rta_len = (void *)RTA_TAIL(rta) - (void *)nest;
return rta->rta_len;
}
int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len)
{
return parse_rtattr_flags(tb, max, rta, len, 0);
}
int parse_rtattr_flags(struct rtattr *tb[], int max, struct rtattr *rta,
int len, unsigned short flags)
{
unsigned short type;
memset(tb, 0, sizeof(struct rtattr *) * (max + 1));
while (RTA_OK(rta, len)) {
type = rta->rta_type & ~flags;
if ((type <= max) && (!tb[type]))
tb[type] = rta;
rta = RTA_NEXT(rta, len);
}
if (len)
fprintf(stderr, "!!!Deficit %d, rta_len=%d\n",
len, rta->rta_len);
return 0;
}
struct rtattr *parse_rtattr_one(int type, struct rtattr *rta, int len)
{
while (RTA_OK(rta, len)) {
if (rta->rta_type == type)
return rta;
rta = RTA_NEXT(rta, len);
}
if (len)
fprintf(stderr, "!!!Deficit %d, rta_len=%d\n",
len, rta->rta_len);
return NULL;
}
int __parse_rtattr_nested_compat(struct rtattr *tb[], int max,
struct rtattr *rta,
int len)
{
if (RTA_PAYLOAD(rta) < len)
return -1;
if (RTA_PAYLOAD(rta) >= RTA_ALIGN(len) + sizeof(struct rtattr)) {
rta = RTA_DATA(rta) + RTA_ALIGN(len);
return parse_rtattr_nested(tb, max, rta);
}
memset(tb, 0, sizeof(struct rtattr *) * (max + 1));
return 0;
}
static const char *get_nla_type_str(unsigned int attr)
{
switch (attr) {
#define C(x) case NL_ATTR_TYPE_ ## x: return #x
C(U8);
C(U16);
C(U32);
C(U64);
C(STRING);
C(FLAG);
C(NESTED);
C(NESTED_ARRAY);
C(NUL_STRING);
C(BINARY);
C(S8);
C(S16);
C(S32);
C(S64);
C(BITFIELD32);
default:
return "unknown";
}
}
void nl_print_policy(const struct rtattr *attr, FILE *fp)
{
const struct rtattr *pos;
rtattr_for_each_nested(pos, attr) {
const struct rtattr *attr;
fprintf(fp, " policy[%u]:", pos->rta_type & ~NLA_F_NESTED);
rtattr_for_each_nested(attr, pos) {
struct rtattr *tp[NL_POLICY_TYPE_ATTR_MAX + 1];
parse_rtattr_nested(tp, ARRAY_SIZE(tp) - 1, attr);
if (tp[NL_POLICY_TYPE_ATTR_TYPE])
fprintf(fp, "attr[%u]: type=%s",
attr->rta_type & ~NLA_F_NESTED,
get_nla_type_str(rta_getattr_u32(tp[NL_POLICY_TYPE_ATTR_TYPE])));
if (tp[NL_POLICY_TYPE_ATTR_POLICY_IDX])
fprintf(fp, " policy:%u",
rta_getattr_u32(tp[NL_POLICY_TYPE_ATTR_POLICY_IDX]));
if (tp[NL_POLICY_TYPE_ATTR_POLICY_MAXTYPE])
fprintf(fp, " maxattr:%u",
rta_getattr_u32(tp[NL_POLICY_TYPE_ATTR_POLICY_MAXTYPE]));
if (tp[NL_POLICY_TYPE_ATTR_MIN_VALUE_S] && tp[NL_POLICY_TYPE_ATTR_MAX_VALUE_S])
fprintf(fp, " range:[%lld,%lld]",
(signed long long)rta_getattr_u64(tp[NL_POLICY_TYPE_ATTR_MIN_VALUE_S]),
(signed long long)rta_getattr_u64(tp[NL_POLICY_TYPE_ATTR_MAX_VALUE_S]));
if (tp[NL_POLICY_TYPE_ATTR_MIN_VALUE_U] && tp[NL_POLICY_TYPE_ATTR_MAX_VALUE_U])
fprintf(fp, " range:[%llu,%llu]",
(unsigned long long)rta_getattr_u64(tp[NL_POLICY_TYPE_ATTR_MIN_VALUE_U]),
(unsigned long long)rta_getattr_u64(tp[NL_POLICY_TYPE_ATTR_MAX_VALUE_U]));
if (tp[NL_POLICY_TYPE_ATTR_MIN_LENGTH])
fprintf(fp, " min len:%u",
rta_getattr_u32(tp[NL_POLICY_TYPE_ATTR_MIN_LENGTH]));
if (tp[NL_POLICY_TYPE_ATTR_MAX_LENGTH])
fprintf(fp, " max len:%u",
rta_getattr_u32(tp[NL_POLICY_TYPE_ATTR_MAX_LENGTH]));
}
}
}