/* Kernel routing table and interface updates via routing socket. */
int
kernel_read (struct thread *thread)
{
int sock;
int nbytes;
struct rt_msghdr *rtm;
union
{
/* Routing information. */
struct
{
struct rt_msghdr rtm;
struct sockaddr addr[RTAX_MAX];
} r;
/* Interface information. */
struct
{
struct if_msghdr ifm;
struct sockaddr addr[RTAX_MAX];
} im;
/* Interface address information. */
struct
{
struct ifa_msghdr ifa;
struct sockaddr addr[RTAX_MAX];
} ia;
#ifdef RTM_IFANNOUNCE
/* Interface arrival/departure */
struct
{
struct if_announcemsghdr ifan;
struct sockaddr addr[RTAX_MAX];
} ian;
#endif /* RTM_IFANNOUNCE */
} buf;
/* Fetch routing socket. */
sock = THREAD_FD (thread);
nbytes= read (sock, &buf, sizeof buf);
if (nbytes <= 0)
{
if (nbytes < 0 && errno != EWOULDBLOCK)
zlog_warn ("routing socket error: %s", strerror (errno));
return 0;
}
thread_add_read (master, kernel_read, NULL, sock);
#ifdef DEBUG
rtmsg_debug (&buf.r.rtm);
#endif /* DEBUG */
rtm = &buf.r.rtm;
switch (rtm->rtm_type)
{
case RTM_ADD:
case RTM_DELETE:
rtm_read (rtm);
break;
case RTM_IFINFO:
ifm_read (&buf.im.ifm);
break;
case RTM_NEWADDR:
case RTM_DELADDR:
ifam_read (&buf.ia.ifa);
break;
#ifdef RTM_IFANNOUNCE
case RTM_IFANNOUNCE:
ifan_read (&buf.ian.ifan);
break;
#endif /* RTM_IFANNOUNCE */
default:
break;
}
return 0;
}
/* Kernel routing table and interface updates via routing socket. */
static int
kernel_read (struct thread *thread)
{
int sock;
int nbytes;
struct rt_msghdr *rtm;
/*
* This must be big enough for any message the kernel might send.
* Rather than determining how many sockaddrs of what size might be
* in each particular message, just use RTAX_MAX of sockaddr_storage
* for each. Note that the sockaddrs must be after each message
* definition, or rather after whichever happens to be the largest,
* since the buffer needs to be big enough for a message and the
* sockaddrs together.
*/
union
{
/* Routing information. */
struct
{
struct rt_msghdr rtm;
struct sockaddr_storage addr[RTAX_MAX];
} r;
/* Interface information. */
struct
{
struct if_msghdr ifm;
struct sockaddr_storage addr[RTAX_MAX];
} im;
/* Interface address information. */
struct
{
struct ifa_msghdr ifa;
struct sockaddr_storage addr[RTAX_MAX];
} ia;
#ifdef RTM_IFANNOUNCE
/* Interface arrival/departure */
struct
{
struct if_announcemsghdr ifan;
struct sockaddr_storage addr[RTAX_MAX];
} ian;
#endif /* RTM_IFANNOUNCE */
} buf;
/* Fetch routing socket. */
sock = THREAD_FD (thread);
nbytes= read (sock, &buf, sizeof buf);
if (nbytes <= 0)
{
if (nbytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN)
zlog_warn ("routing socket error: %s", safe_strerror (errno));
return 0;
}
thread_add_read (zebrad.master, kernel_read, NULL, sock);
if (IS_ZEBRA_DEBUG_KERNEL)
rtmsg_debug (&buf.r.rtm);
rtm = &buf.r.rtm;
/*
* Ensure that we didn't drop any data, so that processing routines
* can assume they have the whole message.
*/
if (rtm->rtm_msglen != nbytes)
{
zlog_warn ("kernel_read: rtm->rtm_msglen %d, nbytes %d, type %d\n",
rtm->rtm_msglen, nbytes, rtm->rtm_type);
return -1;
}
switch (rtm->rtm_type)
{
case RTM_ADD:
case RTM_DELETE:
case RTM_CHANGE:
rtm_read (rtm);
break;
case RTM_IFINFO:
ifm_read (&buf.im.ifm);
break;
case RTM_NEWADDR:
case RTM_DELADDR:
ifam_read (&buf.ia.ifa);
break;
#ifdef RTM_IFANNOUNCE
case RTM_IFANNOUNCE:
ifan_read (&buf.ian.ifan);
break;
#endif /* RTM_IFANNOUNCE */
default:
if (IS_ZEBRA_DEBUG_KERNEL)
zlog_debug("Unprocessed RTM_type: %d", rtm->rtm_type);
break;
}
return 0;
}
