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bird/sysdep/bsd/krt-sock.c
Stefan Haller a7c9515ebc BSD: Fix invalid pointer derefence in logging code 
For logging purposes a stack allocated net_addr struct was passed by
value as vararg (instead of the expected pointer). This resulted in
a segfault when the specific error condition got logged.
2021-04-19 15:06:42 +02:00

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/*
* BIRD -- BSD Routing Table Syncing
*
* (c) 2004 Ondrej Filip <feela@network.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/param.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/ioctl.h>
#include <netinet/in.h>
#include <net/route.h>
#include <net/if.h>
#include <net/if_dl.h>
#undef LOCAL_DEBUG
#include "nest/bird.h"
#include "nest/iface.h"
#include "nest/route.h"
#include "nest/protocol.h"
#include "nest/iface.h"
#include "sysdep/unix/unix.h"
#include "sysdep/unix/krt.h"
#include "lib/string.h"
#include "lib/socket.h"
const int rt_default_ecmp = 0;
/*
* There are significant differences in multiple tables support between BSD variants.
*
* OpenBSD has table_id field for routes in route socket protocol, therefore all
* tables could be managed by one kernel socket. FreeBSD lacks such field,
* therefore multiple sockets (locked to specific table using SO_SETFIB socket
* option) must be used.
*
* Both FreeBSD and OpenBSD uses separate scans for each table. In OpenBSD,
* table_id is specified explicitly as sysctl scan argument, while in FreeBSD it
* is handled implicitly by changing default table using setfib() syscall.
*
* KRT_SHARED_SOCKET - use shared kernel socked instead of one for each krt_proto
* KRT_USE_SETFIB_SCAN - use setfib() for sysctl() route scan
* KRT_USE_SETFIB_SOCK - use SO_SETFIB socket option for kernel sockets
* KRT_USE_SYSCTL_7 - use 7-th arg of sysctl() as table id for route scans
* KRT_USE_SYSCTL_NET_FIBS - use net.fibs sysctl() for dynamic max number of fibs
*/
#ifdef __FreeBSD__
#define KRT_MAX_TABLES 256
#define KRT_USE_SETFIB_SCAN
#define KRT_USE_SETFIB_SOCK
#define KRT_USE_SYSCTL_NET_FIBS
#endif
#ifdef __OpenBSD__
#define KRT_MAX_TABLES (RT_TABLEID_MAX+1)
#define KRT_SHARED_SOCKET
#define KRT_USE_SYSCTL_7
#endif
#ifndef KRT_MAX_TABLES
#define KRT_MAX_TABLES 1
#endif
/* Dynamic max number of tables */
uint krt_max_tables;
#ifdef KRT_USE_SYSCTL_NET_FIBS
static uint
krt_get_max_tables(void)
{
int fibs;
size_t fibs_len = sizeof(fibs);
if (sysctlbyname("net.fibs", &fibs, &fibs_len, NULL, 0) < 0)
{
log(L_WARN "KRT: unable to get max number of fib tables: %m");
return 1;
}
/* Should not happen */
if (fibs < 1)
return 1;
return (uint) MIN(fibs, KRT_MAX_TABLES);
}
#else
static int
krt_get_max_tables(void)
{
return KRT_MAX_TABLES;
}
#endif /* KRT_USE_SYSCTL_NET_FIBS */
/* setfib() syscall for FreeBSD scans */
#ifdef KRT_USE_SETFIB_SCAN
/*
static int krt_default_fib;
static int
krt_get_active_fib(void)
{
int fib;
size_t fib_len = sizeof(fib);
if (sysctlbyname("net.my_fibnum", &fib, &fib_len, NULL, 0) < 0)
{
log(L_WARN "KRT: unable to get active fib number: %m");
return 0;
}
return fib;
}
*/
extern int setfib(int fib);
#endif /* KRT_USE_SETFIB_SCAN */
/* table_id -> krt_proto map */
#ifdef KRT_SHARED_SOCKET
static struct krt_proto *krt_table_map[KRT_MAX_TABLES][2];
#endif
/* Route socket message processing */
int
krt_capable(rte *e)
{
rta *a = e->attrs;
return
((a->dest == RTD_UNICAST && !a->nh.next) /* No multipath support */
#ifdef RTF_REJECT
|| a->dest == RTD_UNREACHABLE
#endif
#ifdef RTF_BLACKHOLE
|| a->dest == RTD_BLACKHOLE
#endif
);
}
#ifndef RTAX_MAX
#define RTAX_MAX 8
#endif
struct ks_msg
{
struct rt_msghdr rtm;
struct sockaddr_storage buf[RTAX_MAX];
} PACKED;
#define ROUNDUP(a) \
((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
#define NEXTADDR(w, u) \
if (msg.rtm.rtm_addrs & (w)) {\
l = ROUNDUP(((struct sockaddr *)&(u))->sa_len);\
memmove(body, &(u), l); body += l;}
#define GETADDR(p, F) \
bzero(p, sizeof(*p));\
if ((addrs & (F)) && ((struct sockaddr *)body)->sa_len) {\
uint l = ROUNDUP(((struct sockaddr *)body)->sa_len);\
memcpy(p, body, (l > sizeof(*p) ? sizeof(*p) : l));\
body += l;}
static inline void
sockaddr_fill_dl(struct sockaddr_dl *sa, struct iface *ifa)
{
uint len = OFFSETOF(struct sockaddr_dl, sdl_data);
memset(sa, 0, len);
sa->sdl_len = len;
sa->sdl_family = AF_LINK;
sa->sdl_index = ifa->index;
}
static int
krt_send_route(struct krt_proto *p, int cmd, rte *e)
{
net *net = e->net;
rta *a = e->attrs;
static int msg_seq;
struct iface *j, *i = a->nh.iface;
int l;
struct ks_msg msg;
char *body = (char *)msg.buf;
sockaddr gate, mask, dst;
DBG("krt-sock: send %I/%d via %I\n", net->n.prefix, net->n.pxlen, a->gw);
bzero(&msg,sizeof (struct rt_msghdr));
msg.rtm.rtm_version = RTM_VERSION;
msg.rtm.rtm_type = cmd;
msg.rtm.rtm_seq = msg_seq++;
msg.rtm.rtm_addrs = RTA_DST;
msg.rtm.rtm_flags = RTF_UP | RTF_PROTO1;
/* XXXX */
if (net_pxlen(net->n.addr) == net_max_prefix_length[net->n.addr->type])
msg.rtm.rtm_flags |= RTF_HOST;
else
msg.rtm.rtm_addrs |= RTA_NETMASK;
#ifdef KRT_SHARED_SOCKET
msg.rtm.rtm_tableid = KRT_CF->sys.table_id;
#endif
#ifdef RTF_REJECT
if(a->dest == RTD_UNREACHABLE)
msg.rtm.rtm_flags |= RTF_REJECT;
#endif
#ifdef RTF_BLACKHOLE
if(a->dest == RTD_BLACKHOLE)
msg.rtm.rtm_flags |= RTF_BLACKHOLE;
#endif
/*
* This is really very nasty, but I'm not able to add reject/blackhole route
* without gateway address.
*/
if (!i)
{
WALK_LIST(j, iface_list)
{
if (j->flags & IF_LOOPBACK)
{
i = j;
break;
}
}
if (!i)
{
log(L_ERR "KRT: Cannot find loopback iface");
return -1;
}
}
int af = AF_UNSPEC;
switch (net->n.addr->type) {
case NET_IP4:
af = AF_INET;
break;
case NET_IP6:
af = AF_INET6;
break;
default:
log(L_ERR "KRT: Not sending route %N to kernel", net->n.addr);
return -1;
}
sockaddr_fill(&dst, af, net_prefix(net->n.addr), NULL, 0);
sockaddr_fill(&mask, af, net_pxmask(net->n.addr), NULL, 0);
switch (a->dest)
{
case RTD_UNICAST:
if (ipa_nonzero(a->nh.gw))
{
ip_addr gw = a->nh.gw;
/* Embed interface ID to link-local address */
if (ipa_is_link_local(gw))
_I0(gw) = 0xfe800000 | (i->index & 0x0000ffff);
sockaddr_fill(&gate, af, gw, NULL, 0);
msg.rtm.rtm_flags |= RTF_GATEWAY;
msg.rtm.rtm_addrs |= RTA_GATEWAY;
break;
}
#ifdef RTF_REJECT
case RTD_UNREACHABLE:
#endif
#ifdef RTF_BLACKHOLE
case RTD_BLACKHOLE:
#endif
{
/* Fallback for all other valid cases */
#if __OpenBSD__
/* Keeping temporarily old code for OpenBSD */
struct ifa *addr = (net->n.addr->type == NET_IP4) ? i->addr4 : (i->addr6 ?: i->llv6);
if (!addr)
{
log(L_ERR "KRT: interface %s has no IP addess", i->name);
return -1;
}
/* Embed interface ID to link-local address */
ip_addr gw = addr->ip;
if (ipa_is_link_local(gw))
_I0(gw) = 0xfe800000 | (i->index & 0x0000ffff);
sockaddr_fill(&gate, af, gw, i, 0);
#else
sockaddr_fill_dl(&gate, i);
#endif
msg.rtm.rtm_addrs |= RTA_GATEWAY;
break;
}
default:
bug("krt-sock: unknown flags, but not filtered");
}
msg.rtm.rtm_index = i->index;
NEXTADDR(RTA_DST, dst);
NEXTADDR(RTA_GATEWAY, gate);
NEXTADDR(RTA_NETMASK, mask);
l = body - (char *)&msg;
msg.rtm.rtm_msglen = l;
if ((l = write(p->sys.sk->fd, (char *)&msg, l)) < 0) {
log(L_ERR "KRT: Error sending route %N to kernel: %m", net->n.addr);
return -1;
}
return 0;
}
void
krt_replace_rte(struct krt_proto *p, net *n, rte *new, rte *old)
{
int err = 0;
if (old)
krt_send_route(p, RTM_DELETE, old);
if (new)
err = krt_send_route(p, RTM_ADD, new);
if (new)
{
if (err < 0)
bmap_clear(&p->sync_map, new->id);
else
bmap_set(&p->sync_map, new->id);
}
}
#define SKIP(ARG...) do { DBG("KRT: Ignoring route - " ARG); return; } while(0)
static void
krt_read_route(struct ks_msg *msg, struct krt_proto *p, int scan)
{
/* p is NULL iff KRT_SHARED_SOCKET and !scan */
int ipv6;
rte *e;
net *net;
sockaddr dst, gate, mask;
ip_addr idst, igate, imask;
net_addr ndst;
void *body = (char *)msg->buf;
int new = (msg->rtm.rtm_type != RTM_DELETE);
char *errmsg = "KRT: Invalid route received";
int flags = msg->rtm.rtm_flags;
int addrs = msg->rtm.rtm_addrs;
int src;
byte src2;
if (!(flags & RTF_UP) && scan)
SKIP("not up in scan\n");
if (!(flags & RTF_DONE) && !scan)
SKIP("not done in async\n");
if (flags & RTF_LLINFO)
SKIP("link-local\n");
GETADDR(&dst, RTA_DST);
GETADDR(&gate, RTA_GATEWAY);
GETADDR(&mask, RTA_NETMASK);
switch (dst.sa.sa_family) {
case AF_INET:
ipv6 = 0;
break;
case AF_INET6:
ipv6 = 1;
break;
default:
SKIP("invalid DST");
}
/* We do not test family for RTA_NETMASK, because BSD sends us
some strange values, but interpreting them as IPv4/IPv6 works */
mask.sa.sa_family = dst.sa.sa_family;
idst = ipa_from_sa(&dst);
imask = ipa_from_sa(&mask);
igate = (gate.sa.sa_family == dst.sa.sa_family) ? ipa_from_sa(&gate) : IPA_NONE;
#ifdef KRT_SHARED_SOCKET
if (!scan)
{
int table_id = msg->rtm.rtm_tableid;
p = (table_id < KRT_MAX_TABLES) ? krt_table_map[table_id][ipv6] : NULL;
if (!p)
SKIP("unknown table id %d\n", table_id);
}
#endif
if ((!ipv6) && (p->p.main_channel->table->addr_type != NET_IP4))
SKIP("reading only IPv4 routes");
if ( ipv6 && (p->p.main_channel->table->addr_type != NET_IP6))
SKIP("reading only IPv6 routes");
int c = ipa_classify_net(idst);
if ((c < 0) || !(c & IADDR_HOST) || ((c & IADDR_SCOPE_MASK) <= SCOPE_LINK))
SKIP("strange class/scope\n");
int pxlen;
if (ipv6)
pxlen = (flags & RTF_HOST) ? IP6_MAX_PREFIX_LENGTH : ip6_masklen(&ipa_to_ip6(imask));
else
pxlen = (flags & RTF_HOST) ? IP4_MAX_PREFIX_LENGTH : ip4_masklen(ipa_to_ip4(imask));
if (pxlen < 0)
{ log(L_ERR "%s (%I) - netmask %I", errmsg, idst, imask); return; }
if (ipv6)
net_fill_ip6(&ndst, ipa_to_ip6(idst), pxlen);
else
net_fill_ip4(&ndst, ipa_to_ip4(idst), pxlen);
if ((flags & RTF_GATEWAY) && ipa_zero(igate))
{ log(L_ERR "%s (%N) - missing gateway", errmsg, &ndst); return; }
u32 self_mask = RTF_PROTO1;
u32 alien_mask = RTF_STATIC | RTF_PROTO1 | RTF_GATEWAY;
src2 = (flags & RTF_STATIC) ? 1 : 0;
src2 |= (flags & RTF_PROTO1) ? 2 : 0;
#ifdef RTF_PROTO2
alien_mask |= RTF_PROTO2;
src2 |= (flags & RTF_PROTO2) ? 4 : 0;
#endif
#ifdef RTF_PROTO3
alien_mask |= RTF_PROTO3;
src2 |= (flags & RTF_PROTO3) ? 8 : 0;
#endif
#ifdef RTF_REJECT
alien_mask |= RTF_REJECT;
#endif
#ifdef RTF_BLACKHOLE
alien_mask |= RTF_BLACKHOLE;
#endif
if (flags & (RTF_DYNAMIC | RTF_MODIFIED))
src = KRT_SRC_REDIRECT;
else if (flags & self_mask)
{
if (!scan)
SKIP("echo\n");
src = KRT_SRC_BIRD;
}
else if (flags & alien_mask)
src = KRT_SRC_ALIEN;
else
src = KRT_SRC_KERNEL;
net = net_get(p->p.main_channel->table, &ndst);
rta a = {
.src = p->p.main_source,
.source = RTS_INHERIT,
.scope = SCOPE_UNIVERSE,
};
/* reject/blackhole routes have also set RTF_GATEWAY,
we wil check them first. */
#ifdef RTF_REJECT
if(flags & RTF_REJECT) {
a.dest = RTD_UNREACHABLE;
goto done;
}
#endif
#ifdef RTF_BLACKHOLE
if(flags & RTF_BLACKHOLE) {
a.dest = RTD_BLACKHOLE;
goto done;
}
#endif
a.nh.iface = if_find_by_index(msg->rtm.rtm_index);
if (!a.nh.iface)
{
log(L_ERR "KRT: Received route %N with unknown ifindex %u",
net->n.addr, msg->rtm.rtm_index);
return;
}
a.dest = RTD_UNICAST;
if (flags & RTF_GATEWAY)
{
neighbor *ng;
a.nh.gw = igate;
/* Clean up embedded interface ID returned in link-local address */
if (ipa_is_link_local(a.nh.gw))
_I0(a.nh.gw) = 0xfe800000;
ng = neigh_find(&p->p, a.nh.gw, a.nh.iface, 0);
if (!ng || (ng->scope == SCOPE_HOST))
{
/* Ignore routes with next-hop 127.0.0.1, host routes with such
next-hop appear on OpenBSD for address aliases. */
if (ipa_classify(a.nh.gw) == (IADDR_HOST | SCOPE_HOST))
return;
log(L_ERR "KRT: Received route %N with strange next-hop %I",
net->n.addr, a.nh.gw);
return;
}
}
done:
e = rte_get_temp(&a);
e->net = net;
e->u.krt.src = src;
e->u.krt.proto = src2;
e->u.krt.seen = 0;
e->u.krt.best = 0;
e->u.krt.metric = 0;
if (scan)
krt_got_route(p, e);
else
krt_got_route_async(p, e, new);
}
static void
krt_read_ifannounce(struct ks_msg *msg)
{
struct if_announcemsghdr *ifam = (struct if_announcemsghdr *)&msg->rtm;
if (ifam->ifan_what == IFAN_ARRIVAL)
{
/* Not enough info to create the iface, so we just trigger iface scan */
kif_request_scan();
}
else if (ifam->ifan_what == IFAN_DEPARTURE)
{
struct iface *iface = if_find_by_index(ifam->ifan_index);
/* Interface is destroyed */
if (!iface)
{
DBG("KRT: unknown interface (%s, #%d) going down. Ignoring\n", ifam->ifan_name, ifam->ifan_index);
return;
}
if_delete(iface);
}
DBG("KRT: IFANNOUNCE what: %d index %d name %s\n", ifam->ifan_what, ifam->ifan_index, ifam->ifan_name);
}
static void
krt_read_ifinfo(struct ks_msg *msg, int scan)
{
struct if_msghdr *ifm = (struct if_msghdr *)&msg->rtm;
void *body = (void *)(ifm + 1);
struct sockaddr_dl *dl = NULL;
uint i;
struct iface *iface = NULL, f = {};
int fl = ifm->ifm_flags;
int nlen = 0;
for (i = 1; i<=RTA_IFP; i <<= 1)
{
if (i & ifm->ifm_addrs)
{
if (i == RTA_IFP)
{
dl = (struct sockaddr_dl *)body;
break;
}
body += ROUNDUP(((struct sockaddr *)&(body))->sa_len);
}
}
if (dl && (dl->sdl_family != AF_LINK))
{
log(L_WARN "Ignoring strange IFINFO");
return;
}
if (dl)
nlen = MIN(sizeof(f.name)-1, dl->sdl_nlen);
/* Note that asynchronous IFINFO messages do not contain iface
name, so we have to found an existing iface by iface index */
iface = if_find_by_index(ifm->ifm_index);
if (!iface)
{
/* New interface */
if (!dl)
return; /* No interface name, ignoring */
memcpy(f.name, dl->sdl_data, nlen);
DBG("New interface '%s' found\n", f.name);
}
else if (dl && memcmp(iface->name, dl->sdl_data, nlen))
{
/* Interface renamed */
if_delete(iface);
memcpy(f.name, dl->sdl_data, nlen);
}
else
{
/* Old interface */
memcpy(f.name, iface->name, sizeof(f.name));
}
f.index = ifm->ifm_index;
f.mtu = ifm->ifm_data.ifi_mtu;
if (fl & IFF_UP)
f.flags |= IF_ADMIN_UP;
if (ifm->ifm_data.ifi_link_state != LINK_STATE_DOWN)
f.flags |= IF_LINK_UP; /* up or unknown */
if (fl & IFF_LOOPBACK) /* Loopback */
f.flags |= IF_MULTIACCESS | IF_LOOPBACK | IF_IGNORE;
else if (fl & IFF_POINTOPOINT) /* PtP */
f.flags |= IF_MULTICAST;
else if (fl & IFF_BROADCAST) /* Broadcast */
f.flags |= IF_MULTIACCESS | IF_BROADCAST | IF_MULTICAST;
else
f.flags |= IF_MULTIACCESS; /* NBMA */
iface = if_update(&f);
if (!scan)
if_end_partial_update(iface);
}
static void
krt_read_addr(struct ks_msg *msg, int scan)
{
struct ifa_msghdr *ifam = (struct ifa_msghdr *)&msg->rtm;
void *body = (void *)(ifam + 1);
sockaddr addr, mask, brd;
struct iface *iface = NULL;
struct ifa ifa;
struct sockaddr null;
ip_addr iaddr, imask, ibrd;
int addrs = ifam->ifam_addrs;
int scope, masklen = -1;
int new = (ifam->ifam_type == RTM_NEWADDR);
/* Strange messages with zero (invalid) ifindex appear on OpenBSD */
if (ifam->ifam_index == 0)
return;
if(!(iface = if_find_by_index(ifam->ifam_index)))
{
log(L_ERR "KIF: Received address message for unknown interface %d", ifam->ifam_index);
return;
}
GETADDR (&null, RTA_DST);
GETADDR (&null, RTA_GATEWAY);
GETADDR (&mask, RTA_NETMASK);
GETADDR (&null, RTA_GENMASK);
GETADDR (&null, RTA_IFP);
GETADDR (&addr, RTA_IFA);
GETADDR (&null, RTA_AUTHOR);
GETADDR (&brd, RTA_BRD);
/* Is addr family IP4 or IP6? */
int ipv6;
switch (addr.sa.sa_family) {
case AF_INET: ipv6 = 0; break;
case AF_INET6: ipv6 = 1; break;
default: return;
}
/* We do not test family for RTA_NETMASK, because BSD sends us
some strange values, but interpreting them as IPv4/IPv6 works */
mask.sa.sa_family = addr.sa.sa_family;
iaddr = ipa_from_sa(&addr);
imask = ipa_from_sa(&mask);
ibrd = ipa_from_sa(&brd);
if ((ipv6 ? (masklen = ip6_masklen(&ipa_to_ip6(imask))) : (masklen = ip4_masklen(ipa_to_ip4(imask)))) < 0)
{
log(L_ERR "KIF: Invalid mask %I for %s", imask, iface->name);
return;
}
/* Clean up embedded interface ID returned in link-local address */
if (ipa_is_link_local(iaddr))
_I0(iaddr) = 0xfe800000;
if (ipa_is_link_local(ibrd))
_I0(ibrd) = 0xfe800000;
bzero(&ifa, sizeof(ifa));
ifa.iface = iface;
ifa.ip = iaddr;
scope = ipa_classify(ifa.ip);
if (scope < 0)
{
log(L_ERR "KIF: Invalid interface address %I for %s", ifa.ip, iface->name);
return;
}
ifa.scope = scope & IADDR_SCOPE_MASK;
if (masklen < (ipv6 ? IP6_MAX_PREFIX_LENGTH : IP4_MAX_PREFIX_LENGTH))
{
net_fill_ipa(&ifa.prefix, ifa.ip, masklen);
net_normalize(&ifa.prefix);
if (masklen == ((ipv6 ? IP6_MAX_PREFIX_LENGTH : IP4_MAX_PREFIX_LENGTH) - 1))
ifa.opposite = ipa_opposite_m1(ifa.ip);
if ((!ipv6) && (masklen == IP4_MAX_PREFIX_LENGTH - 2))
ifa.opposite = ipa_opposite_m2(ifa.ip);
if (iface->flags & IF_BROADCAST)
ifa.brd = ibrd;
if (!(iface->flags & IF_MULTIACCESS))
ifa.opposite = ibrd;
}
else if (!(iface->flags & IF_MULTIACCESS) && ipa_nonzero(ibrd))
{
net_fill_ipa(&ifa.prefix, ibrd, (ipv6 ? IP6_MAX_PREFIX_LENGTH : IP4_MAX_PREFIX_LENGTH));
ifa.opposite = ibrd;
ifa.flags |= IA_PEER;
}
else
{
net_fill_ipa(&ifa.prefix, ifa.ip, (ipv6 ? IP6_MAX_PREFIX_LENGTH : IP4_MAX_PREFIX_LENGTH));
ifa.flags |= IA_HOST;
}
if (new)
ifa_update(&ifa);
else
ifa_delete(&ifa);
if (!scan)
if_end_partial_update(iface);
}
static void
krt_read_msg(struct proto *p, struct ks_msg *msg, int scan)
{
/* p is NULL iff KRT_SHARED_SOCKET and !scan */
switch (msg->rtm.rtm_type)
{
case RTM_GET:
if(!scan) return;
case RTM_ADD:
case RTM_DELETE:
case RTM_CHANGE:
krt_read_route(msg, (struct krt_proto *)p, scan);
break;
case RTM_IFANNOUNCE:
krt_read_ifannounce(msg);
break;
case RTM_IFINFO:
krt_read_ifinfo(msg, scan);
break;
case RTM_NEWADDR:
case RTM_DELADDR:
krt_read_addr(msg, scan);
break;
default:
break;
}
}
/* Sysctl based scans */
static byte *krt_buffer;
static size_t krt_buflen, krt_bufmin;
static struct proto *krt_buffer_owner;
static byte *
krt_buffer_update(struct proto *p, size_t *needed)
{
size_t req = *needed;
if ((req > krt_buflen) ||
((p == krt_buffer_owner) && (req < krt_bufmin)))
{
/* min buflen is 32 kB, step is 8 kB, or 128 kB if > 1 MB */
size_t step = (req < 0x100000) ? 0x2000 : 0x20000;
krt_buflen = (req < 0x6000) ? 0x8000 : (req + step);
krt_bufmin = (req < 0x8000) ? 0 : (req - 2*step);
if (krt_buffer)
mb_free(krt_buffer);
krt_buffer = mb_alloc(krt_pool, krt_buflen);
krt_buffer_owner = p;
}
*needed = krt_buflen;
return krt_buffer;
}
static void
krt_buffer_release(struct proto *p)
{
if (p == krt_buffer_owner)
{
mb_free(krt_buffer);
krt_buffer = NULL;
krt_buflen = 0;
krt_buffer_owner = 0;
}
}
static void
krt_sysctl_scan(struct proto *p, int cmd, int table_id)
{
byte *buf, *next;
int mib[7], mcnt;
size_t needed;
struct ks_msg *m;
int retries = 3;
int rv;
mib[0] = CTL_NET;
mib[1] = PF_ROUTE;
mib[2] = 0;
mib[3] = 0; // Set AF to 0 for all available families
mib[4] = cmd;
mib[5] = 0;
mcnt = 6;
#ifdef KRT_USE_SYSCTL_7
if (table_id >= 0)
{
mib[6] = table_id;
mcnt = 7;
}
#endif
#ifdef KRT_USE_SETFIB_SCAN
if (table_id > 0)
if (setfib(table_id) < 0)
{
log(L_ERR "KRT: setfib(%d) failed: %m", table_id);
return;
}
#endif
try:
rv = sysctl(mib, mcnt, NULL, &needed, NULL, 0);
if (rv < 0)
{
/* OpenBSD returns EINVAL for not yet used tables */
if ((errno == EINVAL) && (table_id > 0))
goto exit;
log(L_ERR "KRT: Route scan estimate failed: %m");
goto exit;
}
/* The table is empty */
if (needed == 0)
goto exit;
buf = krt_buffer_update(p, &needed);
rv = sysctl(mib, mcnt, buf, &needed, NULL, 0);
if (rv < 0)
{
/* The buffer size changed since last sysctl ('needed' is not changed) */
if ((errno == ENOMEM) && retries--)
goto try;
log(L_ERR "KRT: Route scan failed: %m");
goto exit;
}
#ifdef KRT_USE_SETFIB_SCAN
if (table_id > 0)
if (setfib(0) < 0)
die("KRT: setfib(%d) failed: %m", 0);
#endif
/* Process received messages */
for (next = buf; next < (buf + needed); next += m->rtm.rtm_msglen)
{
m = (struct ks_msg *)next;
krt_read_msg(p, m, 1);
}
return;
exit:
krt_buffer_release(p);
#ifdef KRT_USE_SETFIB_SCAN
if (table_id > 0)
if (setfib(0) < 0)
die("KRT: setfib(%d) failed: %m", 0);
#endif
}
void
krt_do_scan(struct krt_proto *p)
{
krt_sysctl_scan(&p->p, NET_RT_DUMP, KRT_CF->sys.table_id);
}
void
kif_do_scan(struct kif_proto *p)
{
if_start_update();
krt_sysctl_scan(&p->p, NET_RT_IFLIST, -1);
if_end_update();
}
/* Kernel sockets */
static int
krt_sock_hook(sock *sk, uint size UNUSED)
{
struct ks_msg msg;
int l = read(sk->fd, (char *)&msg, sizeof(msg));
if (l <= 0)
log(L_ERR "krt-sock: read failed");
else
krt_read_msg((struct proto *) sk->data, &msg, 0);
return 0;
}
static void
krt_sock_err_hook(sock *sk, int e UNUSED)
{
krt_sock_hook(sk, 0);
}
static sock *
krt_sock_open(pool *pool, void *data, int table_id UNUSED)
{
sock *sk;
int fd;
fd = socket(PF_ROUTE, SOCK_RAW, AF_UNSPEC);
if (fd < 0)
die("Cannot open kernel socket for routes");
#ifdef KRT_USE_SETFIB_SOCK
if (table_id > 0)
{
if (setsockopt(fd, SOL_SOCKET, SO_SETFIB, &table_id, sizeof(table_id)) < 0)
die("Cannot set FIB %d for kernel socket: %m", table_id);
}
#endif
sk = sk_new(pool);
sk->type = SK_MAGIC;
sk->rx_hook = krt_sock_hook;
sk->err_hook = krt_sock_err_hook;
sk->fd = fd;
sk->data = data;
if (sk_open(sk) < 0)
bug("krt-sock: sk_open failed");
return sk;
}
static u32 krt_table_cf[(KRT_MAX_TABLES+31) / 32][2];
#ifdef KRT_SHARED_SOCKET
static sock *krt_sock;
static int krt_sock_count;
static void
krt_sock_open_shared(void)
{
if (!krt_sock_count)
krt_sock = krt_sock_open(krt_pool, NULL, -1);
krt_sock_count++;
}
static void
krt_sock_close_shared(void)
{
krt_sock_count--;
if (!krt_sock_count)
{
rfree(krt_sock);
krt_sock = NULL;
}
}
int
krt_sys_start(struct krt_proto *p)
{
int id = KRT_CF->sys.table_id;
if (krt_table_cf[id/32][!!(p->af == AF_INET6)] & (1 << (id%32)))
{
log(L_ERR "%s: Multiple kernel syncers defined for table #%d", p->p.name, id);
return 0;
}
krt_table_cf[id/32][!!(p->af == AF_INET6)] |= (1 << (id%32));
krt_table_map[KRT_CF->sys.table_id][!!(p->af == AF_INET6)] = p;
krt_sock_open_shared();
p->sys.sk = krt_sock;
return 1;
}
void
krt_sys_shutdown(struct krt_proto *p)
{
krt_table_cf[(KRT_CF->sys.table_id)/32][!!(p->af == AF_INET6)] &= ~(1 << ((KRT_CF->sys.table_id)%32));
krt_sock_close_shared();
p->sys.sk = NULL;
krt_table_map[KRT_CF->sys.table_id][!!(p->af == AF_INET6)] = NULL;
krt_buffer_release(&p->p);
}
#else
int
krt_sys_start(struct krt_proto *p)
{
int id = KRT_CF->sys.table_id;
if (krt_table_cf[id/32][!!(p->af == AF_INET6)] & (1 << (id%32)))
{
log(L_ERR "%s: Multiple kernel syncers defined for table #%d", p->p.name, id);
return 0;
}
krt_table_cf[id/32][!!(p->af == AF_INET6)] |= (1 << (id%32));
p->sys.sk = krt_sock_open(p->p.pool, p, KRT_CF->sys.table_id);
return 1;
}
void
krt_sys_shutdown(struct krt_proto *p)
{
krt_table_cf[(KRT_CF->sys.table_id)/32][!!(p->af == AF_INET6)] &= ~(1 << ((KRT_CF->sys.table_id)%32));
rfree(p->sys.sk);
p->sys.sk = NULL;
krt_buffer_release(&p->p);
}
#endif /* KRT_SHARED_SOCKET */
/* KRT configuration callbacks */
int
krt_sys_reconfigure(struct krt_proto *p UNUSED, struct krt_config *n, struct krt_config *o)
{
return n->sys.table_id == o->sys.table_id;
}
void
krt_sys_preconfig(struct config *c UNUSED)
{
krt_max_tables = krt_get_max_tables();
bzero(&krt_table_cf, sizeof(krt_table_cf));
}
void krt_sys_init_config(struct krt_config *c)
{
c->sys.table_id = 0; /* Default table */
}
void krt_sys_copy_config(struct krt_config *d, struct krt_config *s)
{
d->sys.table_id = s->sys.table_id;
}
/* KIF misc code */
void
kif_sys_start(struct kif_proto *p UNUSED)
{
}
void
kif_sys_shutdown(struct kif_proto *p)
{
krt_buffer_release(&p->p);
}
int
kif_update_sysdep_addr(struct iface *i)
{
static int fd = -1;
if (fd < 0)
fd = socket(AF_INET, SOCK_DGRAM, 0);
struct ifreq ifr;
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.ifr_name, i->name, IFNAMSIZ);
int rv = ioctl(fd, SIOCGIFADDR, (char *) &ifr);
if (rv < 0)
return 0;
ip4_addr old = i->sysdep;
i->sysdep = ipa_to_ip4(ipa_from_sa4(&ifr.ifr_addr));
return !ip4_equal(i->sysdep, old);
}
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