lib/nwamd/routing_events.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
 */

#include <arpa/inet.h>
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <net/if.h>
#include <net/route.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <sys/fcntl.h>
#include <unistd.h>

#include <libnwam.h>
#include "events.h"
#include "ncp.h"
#include "ncu.h"
#include "util.h"

/*
 * routing_events.c - this file contains routines to retrieve routing socket
 * events and package them for high level processing.
 */

#define RTMBUFSZ    sizeof (struct rt_msghdr) + \
            (RTAX_MAX * sizeof (struct sockaddr_storage))

static void printaddrs(int, void *);
static char *printaddr(void **);
static void *getaddr(int, int, void *);
static void setaddr(int, int *, void *, struct sockaddr *);

union rtm_buf
{
    /* 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;
};

static int v4_sock = -1;
static int v6_sock = -1;
static pthread_t v4_routing, v6_routing;
static int seq = 0;

static const char *
rtmtype_str(int type)
{
    static char typestr[12]; /* strlen("type ") + enough for an int */

    switch (type) {
    case RTM_NEWADDR:
        return ("NEWADDR");
    case RTM_DELADDR:
        return ("DELADDR");
    case RTM_CHGADDR:
        return ("CHGADDR");
    case RTM_FREEADDR:
        return ("FREEADDR");
    default:
        (void) snprintf(typestr, sizeof (typestr), "type %d", type);
        return (typestr);
    }
}

/* ARGSUSED0 */
static void *
routing_events_v4(void *arg)
{
    int n;
    union rtm_buf buffer;
    struct rt_msghdr *rtm;
    struct ifa_msghdr *ifa;
    char *addrs, *if_name;
    struct sockaddr_dl *addr_dl;
    struct sockaddr *addr, *netmask;
    nwamd_event_t ip_event;

    nlog(LOG_DEBUG, "v4 routing socket %d", v4_sock);

    for (;;) {
        rtm = &buffer.r.rtm;
        n = read(v4_sock, &buffer, sizeof (buffer));
        if (n == -1 && errno == EAGAIN) {
            continue;
        } else if (n == -1) {
            nlog(LOG_ERR, "error reading routing socket "
                "%d: %m", v4_sock);
            /* Low likelihood.  What's recovery path?  */
            continue;
        }

        if (rtm->rtm_msglen < n) {
            nlog(LOG_ERR, "only read %d bytes from "
                "routing socket but message claims to be "
                "of length %d", rtm->rtm_msglen);
            continue;
        }

        if (rtm->rtm_version != RTM_VERSION) {
            nlog(LOG_ERR, "tossing routing message of "
                "version %d type %d", rtm->rtm_version,
                rtm->rtm_type);
            continue;
        }

        if (rtm->rtm_msglen != n) {
            nlog(LOG_DEBUG, "routing message of %d size came from "
                "read of %d on socket %d", rtm->rtm_msglen,
                n, v4_sock);
        }

        switch (rtm->rtm_type) {
        case RTM_NEWADDR:
        case RTM_DELADDR:
        case RTM_CHGADDR:
        case RTM_FREEADDR:

            ifa = (void *)rtm;
            addrs = (char *)ifa + sizeof (*ifa);

            nlog(LOG_DEBUG, "v4 routing message %s: "
                "index %d flags %x", rtmtype_str(rtm->rtm_type),
                ifa->ifam_index, ifa->ifam_flags);

            if ((addr = (struct sockaddr *)getaddr(RTA_IFA,
                ifa->ifam_addrs, addrs)) == NULL)
                break;

            /* Ignore routing socket messages for 0.0.0.0 */
            /*LINTED*/
            if (((struct sockaddr_in *)addr)->sin_addr.s_addr
                == INADDR_ANY) {
                nlog(LOG_DEBUG, "routing_events_v4: "
                    "tossing message for 0.0.0.0");
                break;
            }

            if ((netmask = (struct sockaddr *)getaddr(RTA_NETMASK,
                ifa->ifam_addrs, addrs)) == NULL)
                break;

            if ((addr_dl = (struct sockaddr_dl *)getaddr
                (RTA_IFP, ifa->ifam_addrs, addrs)) == NULL)
                break;
            /*
             * We don't use the lladdr in this structure so we can
             * run over it.
             */
            addr_dl->sdl_data[addr_dl->sdl_nlen] = 0;
            if_name = addr_dl->sdl_data; /* no lifnum */

            if (ifa->ifam_index == 0) {
                nlog(LOG_DEBUG, "tossing index 0 message");
                break;
            }
            if (ifa->ifam_type != rtm->rtm_type) {
                nlog(LOG_INFO,
                    "routing_events_v4: unhandled type %d",
                    ifa->ifam_type);
                break;
            }

            printaddrs(ifa->ifam_addrs, addrs);

            /* Create and enqueue IF_STATE event */
            ip_event = nwamd_event_init_if_state(if_name,
                ifa->ifam_flags,
                (rtm->rtm_type == RTM_NEWADDR ||
                rtm->rtm_type == RTM_CHGADDR ? B_TRUE : B_FALSE),
                addr, netmask);
            if (ip_event != NULL)
                nwamd_event_enqueue(ip_event);
            break;
        }
    }
    /* NOTREACHED */
    return (NULL);
}

/* ARGSUSED0 */
static void *
routing_events_v6(void *arg)
{
    int n;
    union rtm_buf buffer;
    struct rt_msghdr *rtm;
    struct ifa_msghdr *ifa;
    char *addrs, *if_name;
    struct sockaddr_dl *addr_dl;
    struct sockaddr *addr, *netmask;
    nwamd_event_t ip_event;

    nlog(LOG_DEBUG, "v6 routing socket %d", v6_sock);

    for (;;) {

        rtm = &buffer.r.rtm;
        n = read(v6_sock, &buffer, sizeof (buffer));
        if (n == -1 && errno == EAGAIN) {
            continue;
        } else if (n == -1) {
            nlog(LOG_ERR, "error reading routing socket "
                "%d: %m", v6_sock);
            /* Low likelihood.  What's recovery path?  */
            continue;
        }

        if (rtm->rtm_msglen < n) {
            nlog(LOG_ERR, "only read %d bytes from "
                "routing socket but message claims to be "
                "of length %d", rtm->rtm_msglen);
            continue;
        }

        if (rtm->rtm_version != RTM_VERSION) {
            nlog(LOG_ERR, "tossing routing message of "
                "version %d type %d", rtm->rtm_version,
                rtm->rtm_type);
            continue;
        }

        if (rtm->rtm_msglen != n) {
            nlog(LOG_DEBUG, "routing message of %d size came from "
                "read of %d on socket %d", rtm->rtm_msglen,
                n, v6_sock);
        }

        switch (rtm->rtm_type) {
        case RTM_NEWADDR:
        case RTM_DELADDR:
        case RTM_CHGADDR:
        case RTM_FREEADDR:

            ifa = (void *)rtm;
            addrs = (char *)ifa + sizeof (*ifa);

            nlog(LOG_DEBUG, "v6 routing message %s: "
                "index %d flags %x", rtmtype_str(rtm->rtm_type),
                ifa->ifam_index, ifa->ifam_flags);

            if ((addr = (struct sockaddr *)getaddr(RTA_IFA,
                ifa->ifam_addrs, addrs)) == NULL)
                break;

            /* Ignore routing socket messages for :: & linklocal */
            /*LINTED*/
            if (IN6_IS_ADDR_UNSPECIFIED(
                &((struct sockaddr_in6 *)addr)->sin6_addr)) {
                nlog(LOG_INFO, "routing_events_v6: "
                    "tossing message for ::");
                break;
            }
            /*LINTED*/
            if (IN6_IS_ADDR_LINKLOCAL(
                &((struct sockaddr_in6 *)addr)->sin6_addr)) {
                nlog(LOG_INFO, "routing_events_v6: "
                    "tossing message for link local address");
                break;
            }

            if ((netmask =
                (struct sockaddr *)getaddr(RTA_NETMASK,
                ifa->ifam_addrs, addrs)) == NULL)
                break;

            if ((addr_dl = (struct sockaddr_dl *)getaddr
                (RTA_IFP, ifa->ifam_addrs, addrs)) == NULL)
                break;
            /*
             * We don't use the lladdr in this structure so we can
             * run over it.
             */
            addr_dl->sdl_data[addr_dl->sdl_nlen] = 0;
            if_name = addr_dl->sdl_data; /* no lifnum */

            if (ifa->ifam_index == 0) {
                nlog(LOG_DEBUG, "tossing index 0 message");
                break;
            }
            if (ifa->ifam_type != rtm->rtm_type) {
                nlog(LOG_DEBUG,
                    "routing_events_v6: unhandled type %d",
                    ifa->ifam_type);
                break;
            }

            printaddrs(ifa->ifam_addrs, addrs);

            /* Create and enqueue IF_STATE event */
            ip_event = nwamd_event_init_if_state(if_name,
                ifa->ifam_flags,
                (rtm->rtm_type == RTM_NEWADDR ||
                rtm->rtm_type == RTM_CHGADDR ? B_TRUE : B_FALSE),
                addr, netmask);
            if (ip_event != NULL)
                nwamd_event_enqueue(ip_event);
            break;

        }
    }
    /* NOTREACHED */
    return (NULL);
}

void
nwamd_routing_events_init(void)
{
    pthread_attr_t attr;

    /*
     * Initialize routing sockets here so that we know the routing threads
     * (and any requests to add a route) will be working with a valid socket
     * by the time we start handling events.
     */
    v4_sock = socket(AF_ROUTE, SOCK_RAW, AF_INET);
    if (v4_sock == -1)
        pfail("failed to open v4 routing socket: %m");

    v6_sock = socket(AF_ROUTE, SOCK_RAW, AF_INET6);
    if (v6_sock == -1)
        pfail("failed to open v6 routing socket: %m");

    (void) pthread_attr_init(&attr);
    (void) pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
    if (pthread_create(&v4_routing, &attr, routing_events_v4, NULL) != 0 ||
        pthread_create(&v6_routing, &attr, routing_events_v6, NULL) != 0)
        pfail("routing thread creation failed");
    (void) pthread_attr_destroy(&attr);
}

void
nwamd_routing_events_fini(void)
{
    (void) pthread_cancel(v4_routing);
    (void) pthread_cancel(v6_routing);
}

void
nwamd_add_route(struct sockaddr *dest, struct sockaddr *mask,
    struct sockaddr *gateway, const char *ifname)
{
    char rtbuf[RTMBUFSZ];
    /* LINTED E_BAD_PTR_CAST_ALIGN */
    struct rt_msghdr *rtm = (struct rt_msghdr *)rtbuf;
    void *addrs = rtbuf + sizeof (struct rt_msghdr);
    struct sockaddr_dl sdl;
    int rlen, index;
    int af;

    af = gateway->sa_family;

    /* retrieve the index value for the interface */
    if ((index = if_nametoindex(ifname)) == 0) {
        nlog(LOG_ERR, "nwamd_add_route: if_nametoindex failed on %s",
            ifname);
        return;
    }

    (void) bzero(&sdl, sizeof (struct sockaddr_dl));
    sdl.sdl_family = AF_LINK;
    sdl.sdl_index = index;

    (void) bzero(rtm, RTMBUFSZ);
    rtm->rtm_pid = getpid();
    rtm->rtm_type = RTM_ADD;
    rtm->rtm_flags = RTF_UP | RTF_STATIC | RTF_GATEWAY;
    rtm->rtm_version = RTM_VERSION;
    rtm->rtm_seq = ++seq;
    rtm->rtm_msglen = sizeof (rtbuf);
    setaddr(RTA_DST, &rtm->rtm_addrs, &addrs, dest);
    setaddr(RTA_GATEWAY, &rtm->rtm_addrs, &addrs, gateway);
    setaddr(RTA_NETMASK, &rtm->rtm_addrs, &addrs, mask);
    setaddr(RTA_IFP, &rtm->rtm_addrs, &addrs, (struct sockaddr *)&sdl);

    if ((rlen = write(af == AF_INET ? v4_sock : v6_sock,
        rtbuf, rtm->rtm_msglen)) < 0) {
        nlog(LOG_ERR, "nwamd_add_route: "
            "got error %s writing to routing socket", strerror(errno));
    } else if (rlen < rtm->rtm_msglen) {
        nlog(LOG_ERR, "nwamd_add_route: "
            "only wrote %d bytes of %d to routing socket\n",
            rlen, rtm->rtm_msglen);
    }
}

static char *
printaddr(void **address)
{
    static char buffer[80];
    sa_family_t family = *(sa_family_t *)*address;
    struct sockaddr_in *s4 = *address;
    struct sockaddr_in6 *s6 = *address;
    struct sockaddr_dl *dl = *address;

    switch (family) {
    case AF_UNSPEC:
        (void) inet_ntop(AF_UNSPEC, &s4->sin_addr, buffer,
            sizeof (buffer));
        *address = (char *)*address + sizeof (*s4);
        break;
    case AF_INET:
        (void) inet_ntop(AF_INET, &s4->sin_addr, buffer,
            sizeof (buffer));
        *address = (char *)*address + sizeof (*s4);
        break;
    case AF_INET6:
        (void) inet_ntop(AF_INET6, &s6->sin6_addr, buffer,
            sizeof (buffer));
        *address = (char *)*address + sizeof (*s6);
        break;
    case AF_LINK:
        (void) snprintf(buffer, sizeof (buffer), "link %.*s",
            dl->sdl_nlen, dl->sdl_data);
        *address = (char *)*address + sizeof (*dl);
        break;
    default:
        /*
         * We can't reliably update the size of this thing
         * because we don't know what its type is.  So bump
         * it by a sockaddr_in and see what happens.  The
         * caller should really make sure this never happens.
         */
        *address = (char *)*address + sizeof (*s4);
        (void) snprintf(buffer, sizeof (buffer),
            "unknown address family %d", family);
        break;
    }
    return (buffer);
}

static void
printaddrs(int mask, void *address)
{
    if (mask == 0)
        return;
    if (mask & RTA_DST)
        nlog(LOG_DEBUG, "destination address: %s", printaddr(&address));
    if (mask & RTA_GATEWAY)
        nlog(LOG_DEBUG, "gateway address: %s", printaddr(&address));
    if (mask & RTA_NETMASK)
        nlog(LOG_DEBUG, "netmask: %s", printaddr(&address));
    if (mask & RTA_GENMASK)
        nlog(LOG_DEBUG, "cloning mask: %s", printaddr(&address));
    if (mask & RTA_IFP)
        nlog(LOG_DEBUG, "interface name: %s", printaddr(&address));
    if (mask & RTA_IFA)
        nlog(LOG_DEBUG, "interface address: %s", printaddr(&address));
    if (mask & RTA_AUTHOR)
        nlog(LOG_DEBUG, "author: %s", printaddr(&address));
    if (mask & RTA_BRD)
        nlog(LOG_DEBUG, "broadcast address: %s", printaddr(&address));
}

static void
nextaddr(void **address)
{
    sa_family_t family = *(sa_family_t *)*address;

    switch (family) {
    case AF_UNSPEC:
    case AF_INET:
        *address = (char *)*address + sizeof (struct sockaddr_in);
        break;
    case AF_INET6:
        *address = (char *)*address + sizeof (struct sockaddr_in6);
        break;
    case AF_LINK:
        *address = (char *)*address + sizeof (struct sockaddr_dl);
        break;
    default:
        nlog(LOG_ERR, "unknown af (%d) while parsing rtm", family);
        break;
    }
}

static void *
getaddr(int addrid, int mask, void *addresses)
{
    int i;
    void *p = addresses;

    if ((mask & addrid) == 0)
        return (NULL);

    for (i = 1; i < addrid; i <<= 1) {
        if (i & mask)
            nextaddr(&p);
    }
    return (p);
}

static void
setaddr(int addrid, int *maskp, void *addressesp, struct sockaddr *address)
{
    struct sockaddr *p = *((struct sockaddr **)addressesp);

    *maskp |= addrid;

    switch (address->sa_family) {
    case AF_INET:
        (void) memcpy(p, address, sizeof (struct sockaddr_in));
        break;
    case AF_INET6:
        (void) memcpy(p, address, sizeof (struct sockaddr_in6));
        break;
    case AF_LINK:
        (void) memcpy(p, address, sizeof (struct sockaddr_dl));
        break;
    default:
        nlog(LOG_ERR, "setaddr: unknown af (%d) while setting addr",
            address->sa_family);
        break;
    }
    nextaddr(addressesp);
}