freebsd-dev/sbin/route/route_netlink.c
Alexander V. Chernikov 656a39c1a0 netlink: use newly-added snl(3) array parsing for handling multipath
routes.

MFC after:	2 weeks
2023-05-27 11:13:14 +00:00

909 lines
22 KiB
C

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <err.h>
#include <errno.h>
#include <sys/bitcount.h>
#include <sys/param.h>
#include <sys/linker.h>
#include <sys/module.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <netlink/netlink.h>
#include <netlink/netlink_route.h>
#include <netlink/netlink_snl.h>
#include <netlink/netlink_snl_route.h>
#include <netlink/netlink_snl_route_compat.h>
#include <netlink/netlink_snl_route_parsers.h>
const char *routename(struct sockaddr *);
const char *netname(struct sockaddr *);
void printb(int, const char *);
extern const char routeflags[];
extern int verbose, debugonly;
int rtmsg_nl(int cmd, int rtm_flags, int fib, int rtm_addrs, struct sockaddr_storage *so,
struct rt_metrics *rt_metrics);
int flushroutes_fib_nl(int fib, int af);
void monitor_nl(int fib);
struct nl_helper;
struct snl_msg_info;
static void print_getmsg(struct nl_helper *h, struct nlmsghdr *hdr,
struct sockaddr *dst);
static void print_nlmsg(struct nl_helper *h, struct nlmsghdr *hdr,
struct snl_msg_info *cinfo);
#define s6_addr32 __u6_addr.__u6_addr32
#define bitcount32(x) __bitcount32((uint32_t)(x))
static int
inet6_get_plen(const struct in6_addr *addr)
{
return (bitcount32(addr->s6_addr32[0]) + bitcount32(addr->s6_addr32[1]) +
bitcount32(addr->s6_addr32[2]) + bitcount32(addr->s6_addr32[3]));
}
static void
ip6_writemask(struct in6_addr *addr6, uint8_t mask)
{
uint32_t *cp;
for (cp = (uint32_t *)addr6; mask >= 32; mask -= 32)
*cp++ = 0xFFFFFFFF;
if (mask > 0)
*cp = htonl(mask ? ~((1 << (32 - mask)) - 1) : 0);
}
static struct sockaddr *
get_netmask(struct snl_state *ss, int family, int plen)
{
if (family == AF_INET) {
if (plen == 32)
return (NULL);
struct sockaddr_in *sin = snl_allocz(ss, sizeof(*sin));
sin->sin_len = sizeof(*sin);
sin->sin_family = family;
sin->sin_addr.s_addr = htonl(plen ? ~((1 << (32 - plen)) - 1) : 0);
return (struct sockaddr *)sin;
} else if (family == AF_INET6) {
if (plen == 128)
return (NULL);
struct sockaddr_in6 *sin6 = snl_allocz(ss, sizeof(*sin6));
sin6->sin6_len = sizeof(*sin6);
sin6->sin6_family = family;
ip6_writemask(&sin6->sin6_addr, plen);
return (struct sockaddr *)sin6;
}
return (NULL);
}
static void
nl_init_socket(struct snl_state *ss)
{
if (snl_init(ss, NETLINK_ROUTE))
return;
if (modfind("netlink") == -1 && errno == ENOENT) {
/* Try to load */
if (kldload("netlink") == -1)
err(1, "netlink is not loaded and load attempt failed");
if (snl_init(ss, NETLINK_ROUTE))
return;
}
err(1, "unable to open netlink socket");
}
struct nl_helper {
struct snl_state ss_cmd;
};
static void
nl_helper_init(struct nl_helper *h)
{
nl_init_socket(&h->ss_cmd);
}
static void
nl_helper_free(struct nl_helper *h)
{
snl_free(&h->ss_cmd);
}
static struct sockaddr *
get_addr(struct sockaddr_storage *so, int rtm_addrs, int addr_type)
{
struct sockaddr *sa = NULL;
if (rtm_addrs & (1 << addr_type))
sa = (struct sockaddr *)&so[addr_type];
return (sa);
}
static int
rtmsg_nl_int(struct nl_helper *h, int cmd, int rtm_flags, int fib, int rtm_addrs,
struct sockaddr_storage *so, struct rt_metrics *rt_metrics)
{
struct snl_state *ss = &h->ss_cmd;
struct snl_writer nw;
int nl_type = 0, nl_flags = 0;
snl_init_writer(ss, &nw);
switch (cmd) {
case RTSOCK_RTM_ADD:
nl_type = RTM_NEWROUTE;
nl_flags = NLM_F_CREATE | NLM_F_APPEND; /* Do append by default */
break;
case RTSOCK_RTM_CHANGE:
nl_type = RTM_NEWROUTE;
nl_flags = NLM_F_REPLACE;
break;
case RTSOCK_RTM_DELETE:
nl_type = RTM_DELROUTE;
break;
case RTSOCK_RTM_GET:
nl_type = RTM_GETROUTE;
break;
default:
exit(1);
}
struct sockaddr *dst = get_addr(so, rtm_addrs, RTAX_DST);
struct sockaddr *mask = get_addr(so, rtm_addrs, RTAX_NETMASK);
struct sockaddr *gw = get_addr(so, rtm_addrs, RTAX_GATEWAY);
if (dst == NULL)
return (EINVAL);
struct nlmsghdr *hdr = snl_create_msg_request(&nw, nl_type);
hdr->nlmsg_flags |= nl_flags;
int plen = 0;
int rtm_type = RTN_UNICAST;
switch (dst->sa_family) {
case AF_INET:
{
struct sockaddr_in *mask4 = (struct sockaddr_in *)mask;
if ((rtm_flags & RTF_HOST) == 0 && mask4 != NULL)
plen = bitcount32(mask4->sin_addr.s_addr);
else
plen = 32;
break;
}
case AF_INET6:
{
struct sockaddr_in6 *mask6 = (struct sockaddr_in6 *)mask;
if ((rtm_flags & RTF_HOST) == 0 && mask6 != NULL)
plen = inet6_get_plen(&mask6->sin6_addr);
else
plen = 128;
break;
}
default:
return (ENOTSUP);
}
if (rtm_flags & RTF_REJECT)
rtm_type = RTN_PROHIBIT;
else if (rtm_flags & RTF_BLACKHOLE)
rtm_type = RTN_BLACKHOLE;
struct rtmsg *rtm = snl_reserve_msg_object(&nw, struct rtmsg);
rtm->rtm_family = dst->sa_family;
rtm->rtm_protocol = RTPROT_STATIC;
rtm->rtm_type = rtm_type;
rtm->rtm_dst_len = plen;
/* Request exact prefix match if mask is set */
if ((cmd == RTSOCK_RTM_GET) && (mask != NULL))
rtm->rtm_flags = RTM_F_PREFIX;
snl_add_msg_attr_ip(&nw, RTA_DST, dst);
snl_add_msg_attr_u32(&nw, RTA_TABLE, fib);
uint32_t rta_oif = 0;
if (gw != NULL) {
if (rtm_flags & RTF_GATEWAY) {
if (gw->sa_family == dst->sa_family)
snl_add_msg_attr_ip(&nw, RTA_GATEWAY, gw);
else
snl_add_msg_attr_ipvia(&nw, RTA_VIA, gw);
if (gw->sa_family == AF_INET6) {
struct sockaddr_in6 *gw6 = (struct sockaddr_in6 *)gw;
if (IN6_IS_ADDR_LINKLOCAL(&gw6->sin6_addr))
rta_oif = gw6->sin6_scope_id;
}
} else {
/* Should be AF_LINK */
struct sockaddr_dl *sdl = (struct sockaddr_dl *)gw;
if (sdl->sdl_index != 0)
rta_oif = sdl->sdl_index;
}
}
if (dst->sa_family == AF_INET6 && rta_oif == 0) {
struct sockaddr_in6 *dst6 = (struct sockaddr_in6 *)dst;
if (IN6_IS_ADDR_LINKLOCAL(&dst6->sin6_addr))
rta_oif = dst6->sin6_scope_id;
}
if (rta_oif != 0)
snl_add_msg_attr_u32(&nw, RTA_OIF, rta_oif);
if (rtm_flags != 0)
snl_add_msg_attr_u32(&nw, NL_RTA_RTFLAGS, rtm_flags);
if (rt_metrics->rmx_mtu > 0) {
int off = snl_add_msg_attr_nested(&nw, RTA_METRICS);
snl_add_msg_attr_u32(&nw, RTAX_MTU, rt_metrics->rmx_mtu);
snl_end_attr_nested(&nw, off);
}
if (rt_metrics->rmx_weight > 0)
snl_add_msg_attr_u32(&nw, NL_RTA_WEIGHT, rt_metrics->rmx_weight);
if (snl_finalize_msg(&nw) && snl_send_message(ss, hdr)) {
struct snl_errmsg_data e = {};
hdr = snl_read_reply(ss, hdr->nlmsg_seq);
if (nl_type == NL_RTM_GETROUTE) {
if (hdr->nlmsg_type == NL_RTM_NEWROUTE)
print_getmsg(h, hdr, dst);
else {
snl_parse_errmsg(ss, hdr, &e);
if (e.error == ESRCH)
warn("route has not been found");
else
warn("message indicates error %d", e.error);
}
return (0);
}
if (snl_parse_errmsg(ss, hdr, &e))
return (e.error);
}
return (EINVAL);
}
int
rtmsg_nl(int cmd, int rtm_flags, int fib, int rtm_addrs,
struct sockaddr_storage *so, struct rt_metrics *rt_metrics)
{
struct nl_helper h = {};
nl_helper_init(&h);
int error = rtmsg_nl_int(&h, cmd, rtm_flags, fib, rtm_addrs, so, rt_metrics);
nl_helper_free(&h);
return (error);
}
static void
get_ifdata(struct nl_helper *h, uint32_t ifindex, struct snl_parsed_link_simple *link)
{
struct snl_state *ss = &h->ss_cmd;
struct snl_writer nw;
snl_init_writer(ss, &nw);
struct nlmsghdr *hdr = snl_create_msg_request(&nw, NL_RTM_GETLINK);
struct ifinfomsg *ifmsg = snl_reserve_msg_object(&nw, struct ifinfomsg);
if (ifmsg != NULL)
ifmsg->ifi_index = ifindex;
if (!snl_finalize_msg(&nw) || !snl_send_message(ss, hdr))
return;
hdr = snl_read_reply(ss, hdr->nlmsg_seq);
if (hdr != NULL && hdr->nlmsg_type == RTM_NEWLINK) {
snl_parse_nlmsg(ss, hdr, &snl_rtm_link_parser_simple, link);
}
if (link->ifla_ifname == NULL) {
char ifname[16];
snprintf(ifname, sizeof(ifname), "if#%u", ifindex);
int len = strlen(ifname);
char *buf = snl_allocz(ss, len + 1);
strlcpy(buf, ifname, len + 1);
link->ifla_ifname = buf;
}
}
static void
print_getmsg(struct nl_helper *h, struct nlmsghdr *hdr, struct sockaddr *dst)
{
struct snl_state *ss = &h->ss_cmd;
struct timespec ts;
struct snl_parsed_route r = { .rtax_weight = RT_DEFAULT_WEIGHT };
if (!snl_parse_nlmsg(ss, hdr, &snl_rtm_route_parser, &r))
return;
struct snl_parsed_link_simple link = {};
get_ifdata(h, r.rta_oif, &link);
if (r.rtax_mtu == 0)
r.rtax_mtu = link.ifla_mtu;
r.rta_rtflags |= (RTF_UP | RTF_DONE);
(void)printf(" route to: %s\n", routename(dst));
if (r.rta_dst)
(void)printf("destination: %s\n", routename(r.rta_dst));
struct sockaddr *mask = get_netmask(ss, r.rtm_family, r.rtm_dst_len);
if (mask)
(void)printf(" mask: %s\n", routename(mask));
if (r.rta_gw && (r.rta_rtflags & RTF_GATEWAY))
(void)printf(" gateway: %s\n", routename(r.rta_gw));
(void)printf(" fib: %u\n", (unsigned int)r.rta_table);
if (link.ifla_ifname)
(void)printf(" interface: %s\n", link.ifla_ifname);
(void)printf(" flags: ");
printb(r.rta_rtflags, routeflags);
struct rt_metrics rmx = {
.rmx_mtu = r.rtax_mtu,
.rmx_weight = r.rtax_weight,
.rmx_expire = r.rta_expire,
};
printf("\n%9s %9s %9s %9s %9s %10s %9s\n", "recvpipe",
"sendpipe", "ssthresh", "rtt,msec", "mtu ", "weight", "expire");
printf("%8lu ", rmx.rmx_recvpipe);
printf("%8lu ", rmx.rmx_sendpipe);
printf("%8lu ", rmx.rmx_ssthresh);
printf("%8lu ", 0UL);
printf("%8lu ", rmx.rmx_mtu);
printf("%8lu ", rmx.rmx_weight);
if (rmx.rmx_expire > 0)
clock_gettime(CLOCK_REALTIME_FAST, &ts);
else
ts.tv_sec = 0;
printf("%8ld \n", (long)(rmx.rmx_expire - ts.tv_sec));
}
static void
print_prefix(struct nl_helper *h, char *buf, int bufsize, struct sockaddr *sa, int plen)
{
int sz = 0;
if (sa == NULL) {
snprintf(buf, bufsize, "<NULL>");
return;
}
switch (sa->sa_family) {
case AF_INET:
{
struct sockaddr_in *sin = (struct sockaddr_in *)sa;
char abuf[INET_ADDRSTRLEN];
inet_ntop(AF_INET, &sin->sin_addr, abuf, sizeof(abuf));
sz = snprintf(buf, bufsize, "%s", abuf);
break;
}
case AF_INET6:
{
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
char abuf[INET6_ADDRSTRLEN];
char *ifname = NULL;
inet_ntop(AF_INET6, &sin6->sin6_addr, abuf, sizeof(abuf));
if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
struct snl_parsed_link_simple link = {};
if (sin6->sin6_scope_id != 0) {
get_ifdata(h, sin6->sin6_scope_id, &link);
ifname = link.ifla_ifname;
}
}
if (ifname == NULL)
sz = snprintf(buf, bufsize, "%s", abuf);
else
sz = snprintf(buf, bufsize, "%s%%%s", abuf, ifname);
break;
}
default:
snprintf(buf, bufsize, "unknown_af#%d", sa->sa_family);
plen = -1;
}
if (plen >= 0)
snprintf(buf + sz, bufsize - sz, "/%d", plen);
}
static int
print_line_prefix(struct nlmsghdr *hdr, struct snl_msg_info *cinfo,
const char *cmd, const char *name)
{
struct timespec tp;
struct tm tm;
char buf[32];
clock_gettime(CLOCK_REALTIME, &tp);
localtime_r(&tp.tv_sec, &tm);
strftime(buf, sizeof(buf), "%T", &tm);
int len = printf("%s.%03ld PID %4u %s %s ", buf, tp.tv_nsec / 1000000,
cinfo->process_id, cmd, name);
return (len);
}
static const char *
get_action_name(struct nlmsghdr *hdr, int new_cmd)
{
if (hdr->nlmsg_type == new_cmd) {
//return ((hdr->nlmsg_flags & NLM_F_REPLACE) ? "replace" : "add");
return ("add/repl");
} else
return ("delete");
}
static void
print_nlmsg_route_nhop(struct nl_helper *h, struct snl_parsed_route *r,
struct rta_mpath_nh *nh, bool first)
{
// gw 10.0.0.1 ifp vtnet0 mtu 1500 table inet.0
if (nh->gw != NULL) {
char gwbuf[128];
print_prefix(h, gwbuf, sizeof(gwbuf), nh->gw, -1);
printf("gw %s ", gwbuf);
}
if (nh->ifindex != 0) {
struct snl_parsed_link_simple link = {};
get_ifdata(h, nh->ifindex, &link);
if (nh->rtax_mtu == 0)
nh->rtax_mtu = link.ifla_mtu;
printf("iface %s ", link.ifla_ifname);
if (nh->rtax_mtu != 0)
printf("mtu %d ", nh->rtax_mtu);
}
if (first) {
switch (r->rtm_family) {
case AF_INET:
printf("table inet.%d", r->rta_table);
break;
case AF_INET6:
printf("table inet6.%d", r->rta_table);
break;
}
}
printf("\n");
}
static void
print_nlmsg_route(struct nl_helper *h, struct nlmsghdr *hdr,
struct snl_msg_info *cinfo)
{
struct snl_parsed_route r = { .rtax_weight = RT_DEFAULT_WEIGHT };
struct snl_state *ss = &h->ss_cmd;
if (!snl_parse_nlmsg(ss, hdr, &snl_rtm_route_parser, &r))
return;
// 20:19:41.333 add route 10.0.0.0/24 gw 10.0.0.1 ifp vtnet0 mtu 1500 table inet.0
const char *cmd = get_action_name(hdr, RTM_NEWROUTE);
int len = print_line_prefix(hdr, cinfo, cmd, "route");
char buf[128];
print_prefix(h, buf, sizeof(buf), r.rta_dst, r.rtm_dst_len);
len += strlen(buf) + 1;
printf("%s ", buf);
switch (r.rtm_type) {
case RTN_BLACKHOLE:
printf("blackhole\n");
return;
case RTN_UNREACHABLE:
printf("unreach(reject)\n");
return;
case RTN_PROHIBIT:
printf("prohibit(reject)\n");
return;
}
if (r.rta_multipath.num_nhops != 0) {
bool first = true;
memset(buf, ' ', sizeof(buf));
buf[len] = '\0';
for (uint32_t i = 0; i < r.rta_multipath.num_nhops; i++) {
struct rta_mpath_nh *nh = r.rta_multipath.nhops[i];
if (!first)
printf("%s", buf);
print_nlmsg_route_nhop(h, &r, nh, first);
first = false;
}
} else {
struct rta_mpath_nh nh = {
.gw = r.rta_gw,
.ifindex = r.rta_oif,
.rtax_mtu = r.rtax_mtu,
};
print_nlmsg_route_nhop(h, &r, &nh, true);
}
}
static const char *operstate[] = {
"UNKNOWN", /* 0, IF_OPER_UNKNOWN */
"NOTPRESENT", /* 1, IF_OPER_NOTPRESENT */
"DOWN", /* 2, IF_OPER_DOWN */
"LLDOWN", /* 3, IF_OPER_LOWERLAYERDOWN */
"TESTING", /* 4, IF_OPER_TESTING */
"DORMANT", /* 5, IF_OPER_DORMANT */
"UP", /* 6, IF_OPER_UP */
};
static void
print_nlmsg_link(struct nl_helper *h, struct nlmsghdr *hdr,
struct snl_msg_info *cinfo)
{
struct snl_parsed_link l = {};
struct snl_state *ss = &h->ss_cmd;
if (!snl_parse_nlmsg(ss, hdr, &snl_rtm_link_parser, &l))
return;
// 20:19:41.333 add iface#3 vtnet0 admin UP oper UP mtu 1500 table inet.0
const char *cmd = get_action_name(hdr, RTM_NEWLINK);
print_line_prefix(hdr, cinfo, cmd, "iface");
printf("iface#%u %s ", l.ifi_index, l.ifla_ifname);
printf("admin %s ", (l.ifi_flags & IFF_UP) ? "UP" : "DOWN");
if (l.ifla_operstate < NL_ARRAY_LEN(operstate))
printf("oper %s ", operstate[l.ifla_operstate]);
if (l.ifla_mtu > 0)
printf("mtu %u ", l.ifla_mtu);
printf("\n");
}
static void
print_nlmsg_addr(struct nl_helper *h, struct nlmsghdr *hdr,
struct snl_msg_info *cinfo)
{
struct snl_parsed_addr attrs = {};
struct snl_state *ss = &h->ss_cmd;
if (!snl_parse_nlmsg(ss, hdr, &snl_rtm_addr_parser, &attrs))
return;
// add addr 192.168.1.1/24 iface vtnet0
const char *cmd = get_action_name(hdr, RTM_NEWADDR);
print_line_prefix(hdr, cinfo, cmd, "addr");
char buf[128];
struct sockaddr *addr = attrs.ifa_local ? attrs.ifa_local : attrs.ifa_address;
print_prefix(h, buf, sizeof(buf), addr, attrs.ifa_prefixlen);
printf("%s ", buf);
struct snl_parsed_link_simple link = {};
get_ifdata(h, attrs.ifa_index, &link);
if (link.ifi_flags & IFF_POINTOPOINT) {
char buf[64];
print_prefix(h, buf, sizeof(buf), attrs.ifa_address, -1);
printf("-> %s ", buf);
}
printf("iface %s ", link.ifla_ifname);
printf("\n");
}
static const char *nudstate[] = {
"INCOMPLETE", /* 0x01(0) */
"REACHABLE", /* 0x02(1) */
"STALE", /* 0x04(2) */
"DELAY", /* 0x08(3) */
"PROBE", /* 0x10(4) */
"FAILED", /* 0x20(5) */
};
#define NUD_INCOMPLETE 0x01 /* No lladdr, address resolution in progress */
#define NUD_REACHABLE 0x02 /* reachable & recently resolved */
#define NUD_STALE 0x04 /* has lladdr but it's stale */
#define NUD_DELAY 0x08 /* has lladdr, is stale, probes delayed */
#define NUD_PROBE 0x10 /* has lladdr, is stale, probes sent */
#define NUD_FAILED 0x20 /* unused */
static void
print_nlmsg_neigh(struct nl_helper *h, struct nlmsghdr *hdr,
struct snl_msg_info *cinfo)
{
struct snl_parsed_neigh attrs = {};
struct snl_state *ss = &h->ss_cmd;
if (!snl_parse_nlmsg(ss, hdr, &snl_rtm_neigh_parser, &attrs))
return;
// add addr 192.168.1.1 state %s lladdr %s iface vtnet0
const char *cmd = get_action_name(hdr, RTM_NEWNEIGH);
print_line_prefix(hdr, cinfo, cmd, "neigh");
char buf[128];
print_prefix(h, buf, sizeof(buf), attrs.nda_dst, -1);
printf("%s ", buf);
struct snl_parsed_link_simple link = {};
get_ifdata(h, attrs.nda_ifindex, &link);
for (unsigned int i = 0; i < NL_ARRAY_LEN(nudstate); i++) {
if ((1 << i) & attrs.ndm_state) {
printf("state %s ", nudstate[i]);
break;
}
}
if (attrs.nda_lladdr != NULL) {
int if_type = link.ifi_type;
if ((if_type == IFT_ETHER || if_type == IFT_L2VLAN || if_type == IFT_BRIDGE) &&
NLA_DATA_LEN(attrs.nda_lladdr) == ETHER_ADDR_LEN) {
struct ether_addr *ll;
ll = (struct ether_addr *)NLA_DATA(attrs.nda_lladdr);
printf("lladdr %s ", ether_ntoa(ll));
} else {
struct sockaddr_dl sdl = {
.sdl_len = sizeof(sdl),
.sdl_family = AF_LINK,
.sdl_index = attrs.nda_ifindex,
.sdl_type = if_type,
.sdl_alen = NLA_DATA_LEN(attrs.nda_lladdr),
};
if (sdl.sdl_alen < sizeof(sdl.sdl_data)) {
void *ll = NLA_DATA(attrs.nda_lladdr);
memcpy(sdl.sdl_data, ll, sdl.sdl_alen);
printf("lladdr %s ", link_ntoa(&sdl));
}
}
}
if (link.ifla_ifname != NULL)
printf("iface %s ", link.ifla_ifname);
printf("\n");
}
static void
print_nlmsg_generic(struct nl_helper *h, struct nlmsghdr *hdr, struct snl_msg_info *cinfo)
{
const char *cmd = get_action_name(hdr, 0);
print_line_prefix(hdr, cinfo, cmd, "unknown message");
printf(" type %u\n", hdr->nlmsg_type);
}
static void
print_nlmsg(struct nl_helper *h, struct nlmsghdr *hdr, struct snl_msg_info *cinfo)
{
switch (hdr->nlmsg_type) {
case RTM_NEWLINK:
case RTM_DELLINK:
print_nlmsg_link(h, hdr, cinfo);
break;
case RTM_NEWADDR:
case RTM_DELADDR:
print_nlmsg_addr(h, hdr, cinfo);
break;
case RTM_NEWROUTE:
case RTM_DELROUTE:
print_nlmsg_route(h, hdr, cinfo);
break;
case RTM_NEWNEIGH:
case RTM_DELNEIGH:
print_nlmsg_neigh(h, hdr, cinfo);
break;
default:
print_nlmsg_generic(h, hdr, cinfo);
}
snl_clear_lb(&h->ss_cmd);
}
void
monitor_nl(int fib)
{
struct snl_state ss_event = {};
struct nl_helper h;
nl_init_socket(&ss_event);
nl_helper_init(&h);
int groups[] = {
RTNLGRP_LINK,
RTNLGRP_NEIGH,
RTNLGRP_NEXTHOP,
#ifdef INET
RTNLGRP_IPV4_IFADDR,
RTNLGRP_IPV4_ROUTE,
#endif
#ifdef INET6
RTNLGRP_IPV6_IFADDR,
RTNLGRP_IPV6_ROUTE,
#endif
};
int optval = 1;
socklen_t optlen = sizeof(optval);
setsockopt(ss_event.fd, SOL_NETLINK, NETLINK_MSG_INFO, &optval, optlen);
for (unsigned int i = 0; i < NL_ARRAY_LEN(groups); i++) {
int error;
int optval = groups[i];
socklen_t optlen = sizeof(optval);
error = setsockopt(ss_event.fd, SOL_NETLINK,
NETLINK_ADD_MEMBERSHIP, &optval, optlen);
if (error != 0)
warn("Unable to subscribe to group %d", optval);
}
struct snl_msg_info attrs = {};
struct nlmsghdr *hdr;
while ((hdr = snl_read_message_dbg(&ss_event, &attrs)) != NULL)
{
print_nlmsg(&h, hdr, &attrs);
snl_clear_lb(&h.ss_cmd);
snl_clear_lb(&ss_event);
}
snl_free(&ss_event);
nl_helper_free(&h);
exit(0);
}
static void
print_flushed_route(struct snl_parsed_route *r, struct sockaddr *gw)
{
struct sockaddr *sa = r->rta_dst;
printf("%-20.20s ", r->rta_rtflags & RTF_HOST ?
routename(sa) : netname(sa));
sa = gw;
printf("%-20.20s ", routename(sa));
printf("-fib %-3d ", r->rta_table);
printf("done\n");
}
static int
flushroute_one(struct nl_helper *h, struct snl_parsed_route *r)
{
struct snl_state *ss = &h->ss_cmd;
struct snl_errmsg_data e = {};
struct snl_writer nw;
snl_init_writer(ss, &nw);
struct nlmsghdr *hdr = snl_create_msg_request(&nw, NL_RTM_DELROUTE);
struct rtmsg *rtm = snl_reserve_msg_object(&nw, struct rtmsg);
rtm->rtm_family = r->rtm_family;
rtm->rtm_dst_len = r->rtm_dst_len;
snl_add_msg_attr_u32(&nw, RTA_TABLE, r->rta_table);
snl_add_msg_attr_ip(&nw, RTA_DST, r->rta_dst);
if (!snl_finalize_msg(&nw) || !snl_send_message(ss, hdr))
return (ENOMEM);
if (!snl_read_reply_code(ss, hdr->nlmsg_seq, &e)) {
return (e.error);
if (e.error == EPERM)
errc(1, e.error, "RTM_DELROUTE failed:");
else
warnc(e.error, "RTM_DELROUTE failed:");
return (true);
};
if (verbose) {
struct snl_msg_info attrs = {};
print_nlmsg(h, hdr, &attrs);
}
else {
if (r->rta_multipath.num_nhops != 0) {
for (uint32_t i = 0; i < r->rta_multipath.num_nhops; i++) {
struct rta_mpath_nh *nh = r->rta_multipath.nhops[i];
print_flushed_route(r, nh->gw);
}
} else
print_flushed_route(r, r->rta_gw);
}
return (0);
}
int
flushroutes_fib_nl(int fib, int af)
{
struct snl_state ss = {};
struct snl_writer nw;
struct nl_helper h = {};
nl_init_socket(&ss);
snl_init_writer(&ss, &nw);
struct nlmsghdr *hdr = snl_create_msg_request(&nw, NL_RTM_GETROUTE);
hdr->nlmsg_flags |= NLM_F_DUMP;
struct rtmsg *rtm = snl_reserve_msg_object(&nw, struct rtmsg);
rtm->rtm_family = af;
snl_add_msg_attr_u32(&nw, RTA_TABLE, fib);
if (!snl_finalize_msg(&nw) || !snl_send_message(&ss, hdr)) {
snl_free(&ss);
return (EINVAL);
}
struct snl_errmsg_data e = {};
uint32_t nlm_seq = hdr->nlmsg_seq;
nl_helper_init(&h);
while ((hdr = snl_read_reply_multi(&ss, nlm_seq, &e)) != NULL) {
struct snl_parsed_route r = { .rtax_weight = RT_DEFAULT_WEIGHT };
int error;
if (!snl_parse_nlmsg(&ss, hdr, &snl_rtm_route_parser, &r))
continue;
if (verbose) {
struct snl_msg_info attrs = {};
print_nlmsg(&h, hdr, &attrs);
}
if (r.rta_table != (uint32_t)fib || r.rtm_family != af)
continue;
if ((r.rta_rtflags & RTF_GATEWAY) == 0)
continue;
if (debugonly)
continue;
if ((error = flushroute_one(&h, &r)) != 0) {
if (error == EPERM)
errc(1, error, "RTM_DELROUTE failed:");
else
warnc(error, "RTM_DELROUTE failed:");
}
snl_clear_lb(&h.ss_cmd);
}
snl_free(&ss);
nl_helper_free(&h);
return (e.error);
}