lib/nwamd/events.c

	events.c revision d71dbb732372504daff1f1783bc0d8864ce9bd50
/*
 * 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 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * This file contains routines to retrieve events from the system and package
 * them for high level processing.
 *
 * struct np_event is the basic event structure.  The np_event structure and
 * its npe_name member are allocated using malloc(3c).  free_event() frees both
 * the npe_name member and the associated np_event structure.
 *
 * np_queue_add_event() and np_queue_get_event() provide functionality for
 * adding events to a queue and blocking on that queue for an event.
 *
 * Functions of the form addevent_*() provide the mechanism to cook down a
 * higher level event into an np_event and put it on the queue.
 *
 * routing_events() reads routing messages off of an IPv4 routing socket and
 * by calling addevent_*() functions places appropriate events on the queue.
 *
 * start_event_collection() creates a thread to run routing_events() and one
 * to run periodic_wireless_scan() in.  Finally it does an initial collection
 * of information from each interface currently known.
 */

#include <arpa/inet.h>
#include <assert.h>
#include <errno.h>
#include <libsysevent.h>
#include <net/if.h>
#include <net/route.h>
#include <pthread.h>
#include <stdlib.h>
#include <string.h>
#include <sys/fcntl.h>
#include <sys/sysevent/eventdefs.h>
#include <syslog.h>
#include <unistd.h>
#include <fcntl.h>

#include "defines.h"
#include "structures.h"
#include "functions.h"
#include "variables.h"

struct np_event *equeue = NULL;
static struct np_event *equeue_end = NULL;

pthread_mutex_t queue_mutex = PTHREAD_MUTEX_INITIALIZER;
pthread_cond_t queue_cond = PTHREAD_COND_INITIALIZER;
pthread_t routing, scan;

static void printaddrs(int mask, void *address);
static char *printaddr(void **address);
static struct sockaddr *dupsockaddr(struct sockaddr *);
static boolean_t cmpsockaddr(struct sockaddr *, struct sockaddr *);
static void *getaddr(int addrid, int mask, void *address);

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;
};

void
free_event(struct np_event *e)
{
    free(e->npe_name);
    free(e);
}

void
np_queue_add_event(struct np_event *e)
{
    (void) pthread_mutex_lock(&queue_mutex);
    if (equeue_end != NULL) {
        equeue_end->npe_next = e;
        equeue_end = e;
    } else {
        equeue = equeue_end = e;
    }
    equeue_end->npe_next = NULL;
    (void) pthread_cond_signal(&queue_cond);
    (void) pthread_mutex_unlock(&queue_mutex);
}

/*
 * Blocking getevent.  This routine will block until there is an event for
 * it to return.
 */
struct np_event *
np_queue_get_event(void)
{
    struct np_event *rv = NULL;

    (void) pthread_mutex_lock(&queue_mutex);

    while (equeue == NULL)
        (void) pthread_cond_wait(&queue_cond, &queue_mutex);

    rv = equeue;
    equeue = equeue->npe_next;
    if (equeue == NULL)
        equeue_end = NULL;

    (void) pthread_mutex_unlock(&queue_mutex);

    rv->npe_next = NULL;
    return (rv);
}

const char *
npe_type_str(enum np_event_type type)
{
    switch (type) {
        case EV_ROUTING:
            return ("ROUTING");
        case EV_SYS:
            return ("SYS");
        case EV_TIMER:
            return ("TIMER");
        case EV_SHUTDOWN:
            return ("SHUTDOWN");
        case EV_NEWADDR:
            return ("NEWADDR");
        default:
            return ("unknown");
    }
}

static void
addevent_routing_ifa(struct ifa_msghdr *ifa, const char *name)
{
    struct np_event *e;

    dprintf("addevent_routing_ifa");
    if (ifa->ifam_index == 0) {
        /* what is this? */
        dprintf("tossing index 0 routing event");
        return;
    }

    e = calloc(1, sizeof (*e));
    if (e == NULL) {
        syslog(LOG_ERR, "calloc failed");
        return;
    }

    switch (ifa->ifam_type) {
    case RTM_NEWADDR:
        assert(name != NULL);
        e->npe_type = EV_NEWADDR;
        if ((e->npe_name = strdup(name)) == NULL) {
            syslog(LOG_ERR, "strdup failed");
            free(e);
            return;
        }
        dprintf("adding event type %s name %s to queue",
            npe_type_str(e->npe_type), STRING(e->npe_name));
        np_queue_add_event(e);
        break;

    default:
        free(e);
        dprintf("unhandled type in addevent_routing_ifa %d",
            ifa->ifam_type);
        break;
    }
}

static void
addevent_routing_msghdr(struct if_msghdr *ifm, const char *name)
{
    struct np_event *e;

    dprintf("addevent_routing_msghdr");
    if (ifm->ifm_index == 0) {
        /* what is this? */
        dprintf("tossing index 0 routing event");
        return;
    }

    switch (ifm->ifm_type) {
    case RTM_IFINFO:
        assert(name != NULL);
        e = calloc(1, sizeof (*e));
        if (e == NULL) {
            syslog(LOG_ERR, "calloc failed");
            return;
        }

        e->npe_type = EV_ROUTING;
        if ((e->npe_name = strdup(name)) == NULL) {
            syslog(LOG_ERR, "strdup failed");
            free(e);
            return;
        }
        dprintf("flags = %x, IFF_RUNNING = %x", ifm->ifm_flags,
            IFF_RUNNING);
        dprintf("adding event type %s name %s to queue",
            npe_type_str(e->npe_type), STRING(e->npe_name));
        np_queue_add_event(e);
        break;

    default:
        dprintf("unhandled type in addevent_routing_msghdr %d",
            ifm->ifm_type);
        break;
    }
}

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

    switch (type) {
        case RTM_ADD:
            return ("ADD");
        case RTM_DELETE:
            return ("DELETE");
        case RTM_NEWADDR:
            return ("NEWADDR");
        case RTM_DELADDR:
            return ("DELADDR");
        case RTM_IFINFO:
            return ("IFINFO");
        default:
            (void) snprintf(typestr, sizeof (typestr), "type %d",
                type);
            return (typestr);
    }
}

/* ARGSUSED */
static void *
routing_events(void *arg)
{
    int rtsock;
    int n;
    union rtm_buf buffer;
    struct rt_msghdr *rtm;
    struct ifa_msghdr *ifa;
    struct if_msghdr *ifm;

    /*
     * We use v4 interfaces as proxies for links so those are the only
     * routing messages we need to listen to.  Look at the comments in
     * structures.h for more information about the split between the
     * llp and interfaces.
     */
    rtsock = socket(AF_ROUTE, SOCK_RAW, AF_INET);
    if (rtsock == -1) {
        syslog(LOG_ERR, "failed to open routing socket: %m");
        exit(EXIT_FAILURE);
    }

    dprintf("routing socket %d", rtsock);

    for (;;) {
        struct interface *ifp;
        char *addrs, *if_name;
        struct sockaddr_dl *addr_dl;
        struct sockaddr *addr;

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

        if (rtm->rtm_msglen < n) {
            syslog(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) {
            syslog(LOG_ERR, "tossing routing message of "
                "version %d type %d", rtm->rtm_version,
                rtm->rtm_type);
            continue;
        }

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

        switch (rtm->rtm_type) {
        case RTM_NEWADDR:
            ifa = (void *)rtm;
            addrs = (char *)ifa + sizeof (*ifa);

            dprintf("routing message NEWADDR: index %d flags %x",
                ifa->ifam_index, ifa->ifam_flags);
            printaddrs(ifa->ifam_addrs, addrs);

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

            if ((addr_dl = (struct sockaddr_dl *)getaddr
                (RTA_IFP, ifa->ifam_addrs, addrs)) == NULL)
                break;
            if_name = addr_dl->sdl_data;
            ifp = get_interface(if_name);
            if (ifp == NULL) {
                dprintf("no interface struct for %s; ignoring "
                    "message", STRING(if_name));
                break;
            }

            /* if no cached address, cache it */
            if (ifp->if_ipaddr == NULL) {
                ifp->if_ipaddr = dupsockaddr(addr);
                dprintf("cached address %s for link %s",
                    printaddr((void **)&addr), if_name);
                addevent_routing_ifa(ifa, if_name);
            } else if (!cmpsockaddr(addr, ifp->if_ipaddr)) {
                free(ifp->if_ipaddr);
                ifp->if_ipaddr = dupsockaddr(addr);
                addevent_routing_ifa(ifa, if_name);
            }
            break;
        case RTM_IFINFO:
        {
            boolean_t plugged_in;

            ifm = (void *)rtm;
            addrs = (char *)ifm + sizeof (*ifm);
            dprintf("routing message IFINFO: index %d flags %x",
                ifm->ifm_index, ifm->ifm_flags);
            printaddrs(ifm->ifm_addrs, addrs);

            if ((addr_dl = (struct sockaddr_dl *)getaddr(RTA_IFP,
                ifm->ifm_addrs, addrs)) == NULL)
                break;
            if_name = addr_dl->sdl_data;
            ifp = get_interface(if_name);
            if (ifp == NULL) {
                dprintf("no interface struct for %s; ignoring "
                    "message", STRING(if_name));
                break;
            }

            /*
             * Check for toggling of the IFF_RUNNING
             * flag.
             *
             * On any change in the flag value, we
             * turn off the DHCPFAILED and DHCPSTARTED
             * flags; the change in the RUNNING state
             * indicates a "fresh start" for the
             * interface, so we should try dhcp again.
             *
             * Ignore specific IFF_RUNNING changes for
             * wireless interfaces; their semantics are
             * a bit different (either the flag is always
             * on, or, with newer drivers, it indicates
             * whether or not they are connected to an AP).
             *
             * For wired interfaces, if the interface was
             * not plugged in and now it is, start info
             * collection.
             *
             * If it was plugged in and now it is
             * unplugged, generate an event.
             *
             * XXX We probably need a lock to protect
             * if_flags setting and getting.
             */
            if ((ifp->if_flags & IFF_RUNNING) !=
                (ifm->ifm_flags & IFF_RUNNING)) {
                ifp->if_lflags &= ~IF_DHCPFAILED;
                ifp->if_lflags &= ~IF_DHCPSTARTED;
            }
            if (ifp->if_type == IF_WIRELESS)
                break;
            plugged_in =
                ((ifp->if_flags & IFF_RUNNING) != 0);
            ifp->if_flags = ifm->ifm_flags;
            if (!plugged_in &&
                (ifm->ifm_flags & IFF_RUNNING)) {
                start_if_info_collect(ifp, NULL);
            } else if (plugged_in &&
                !(ifm->ifm_flags & IFF_RUNNING)) {
                check_drop_dhcp(ifp);
                addevent_routing_msghdr(ifm, if_name);
            }
            break;
        }
        default:
            dprintf("routing message %s socket %d discarded",
                rtmtype_str(rtm->rtm_type), rtsock);
            break;
        }
    }
    /* NOTREACHED */
    return (NULL);
}

/* return B_TRUE if sin_family and sin_addr are the same, B_FALSE if not */
static boolean_t
cmpsockaddr(struct sockaddr *addr1, struct sockaddr *addr2)
{
    struct sockaddr_in *sina, *sinb;
    struct sockaddr_in6 *sin6a, *sin6b;

    if (addr1->sa_family != addr2->sa_family)
        return (B_FALSE);

    switch (addr1->sa_family) {
    case AF_INET:
        /* LINTED E_BAD_PTR_CAST_ALIGN */
        sina = (struct sockaddr_in *)addr1;
        /* LINTED E_BAD_PTR_CAST_ALIGN */
        sinb = (struct sockaddr_in *)addr2;
        return (sina->sin_addr.s_addr == sinb->sin_addr.s_addr);
    case AF_INET6:
        /* LINTED E_BAD_PTR_CAST_ALIGN */
        sin6a = (struct sockaddr_in6 *)addr1;
        /* LINTED E_BAD_PTR_CAST_ALIGN */
        sin6b = (struct sockaddr_in6 *)addr2;
        return
            (IN6_ARE_ADDR_EQUAL(&sin6a->sin6_addr, &sin6b->sin6_addr));
    default:
        dprintf("cmpsockaddr: unsupported af (%d)", addr1->sa_family);
        return (B_FALSE);
    }
}

/*
 * Duplicate a sockaddr. Caller will be responsible for freeing memory when it
 * is no longer needed. Currently only supports AF_INET and AF_INET6
 * (returns NULL otherwise).
 */
static struct sockaddr *
dupsockaddr(struct sockaddr *addr)
{
    struct sockaddr_in *t1, *ret1;
    struct sockaddr_in6 *t2, *ret2;

    switch (addr->sa_family) {
    case AF_INET:
        if ((ret1 = calloc(1, sizeof (struct sockaddr_in))) == NULL) {
            syslog(LOG_ERR, "dupsockaddr: calloc failed");
            return (NULL);
        }
        /* LINTED E_BAD_PTR_CAST_ALIGN */
        t1 = (struct sockaddr_in *)addr;
        ret1->sin_family = t1->sin_family;
        ret1->sin_addr.s_addr = t1->sin_addr.s_addr;
        return ((struct sockaddr *)ret1);
    case AF_INET6:
        if ((ret2 = calloc(1, sizeof (struct sockaddr_in6))) == NULL) {
            syslog(LOG_ERR, "dupsockaddr: calloc failed");
            return (NULL);
        }
        /* LINTED E_BAD_PTR_CAST_ALIGN */
        t2 = (struct sockaddr_in6 *)addr;
        ret2->sin6_family = t2->sin6_family;
        (void) memcpy((void *)&ret2->sin6_addr,
            (const void *)&t2->sin6_addr, sizeof (struct in6_addr));
        return ((struct sockaddr *)ret2);
    default:
        dprintf("dupsockaddr: unsupported af (%d)", addr->sa_family);
        return (NULL);
    }
}

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_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)
        dprintf("destination address: %s", printaddr(&address));
    if (mask & RTA_GATEWAY)
        dprintf("gateway address: %s", printaddr(&address));
    if (mask & RTA_NETMASK)
        dprintf("netmask: %s", printaddr(&address));
    if (mask & RTA_GENMASK)
        dprintf("cloning mask: %s", printaddr(&address));
    if (mask & RTA_IFP)
        dprintf("interface name: %s", printaddr(&address));
    if (mask & RTA_IFA)
        dprintf("interface address: %s", printaddr(&address));
    if (mask & RTA_AUTHOR)
        dprintf("author: %s", printaddr(&address));
    if (mask & RTA_BRD)
        dprintf("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:
        syslog(LOG_ERR, "unknown af (%d) while parsing rtm", family);
        break;
    }
}

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

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

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

boolean_t
start_event_collection(void)
{
    int err;

    /*
     * if these are ever created/destroyed repetitively then we will
     * have to change this.
     */

    if (err = pthread_create(&routing, NULL, routing_events, NULL)) {
        syslog(LOG_ERR, "pthread_create routing: %s", strerror(err));
        exit(EXIT_FAILURE);
    } else {
        dprintf("routing thread: %d", routing);
    }

    if (err = pthread_create(&scan, NULL, periodic_wireless_scan, NULL)) {
        syslog(LOG_ERR, "pthread_create wireless scan: %s",
            strerror(err));
        exit(EXIT_FAILURE);
    } else {
        dprintf("scan thread: %d", scan);
    }

    walk_interface(start_if_info_collect, NULL);

    return (B_TRUE);
}