interface_sysctl.c

开发snmp的开发包有两个开放的SNMP开发库

                    m_speed = t_speed;
                }
            }
            *speed = m_speed;
            *speed_high = m_speed_high;
        }
        free(media_list);
    }

    close(s);

    DEBUGMSGTL(("access:interface:container:sysctl",
                "%s: speed: %u, speed_high: %u\n",
                name, *speed, *speed_high));

    return *speed;
}

/*
 *
 * @retval  0 success
 * @retval -1 no container specified
 * @retval -2 could not get interface info
 * @retval -3 could not create entry (probably malloc)
 */
int
netsnmp_arch_interface_container_load(netsnmp_container* container,
                                               u_int load_flags)
{
    netsnmp_interface_entry *entry = NULL;
    u_char *if_list = NULL, *cp;
    size_t if_list_size = 0;
    struct if_msghdr *ifp;
    int sysctl_oid[] = { CTL_NET, PF_ROUTE, 0, 0, NET_RT_IFLIST, 0 };
    struct ifa_msghdr *ifa;
    struct sockaddr *a;
    struct sockaddr_dl *adl;
    int amask;
    char *if_name;
    int flags;

    DEBUGMSGTL(("access:interface:container:sysctl",
                "load (flags %p)\n", load_flags));

    if (NULL == container) {
        snmp_log(LOG_ERR, "no container specified/found for interface\n");
        return -1;
    }

    if (sysctl(sysctl_oid, sizeof(sysctl_oid)/sizeof(int), 0,
               &if_list_size, 0, 0) == -1) {
        snmp_log(LOG_ERR, "could not get interface info (size)\n");
        return -2;
    }

    if_list = malloc(if_list_size);
    if (if_list == NULL) {
        snmp_log(LOG_ERR, "could not allocate memory for interface info "
                 "(%lu bytes)\n", if_list_size);
        return -3;
    } else {
        DEBUGMSGTL(("access:interface:container:sysctl",
                    "allocated %lu bytes for if_list\n", if_list_size));
    }

    if (sysctl(sysctl_oid, sizeof(sysctl_oid)/sizeof(int), if_list,
               &if_list_size, 0, 0) == -1) {
        snmp_log(LOG_ERR, "could not get interface info\n");
        free(if_list);
        return -2;
    }

    /* 1st pass: create interface entries */
    for (cp = if_list; cp < if_list + if_list_size; cp += ifp->ifm_msglen) {

        ifp = (struct if_msghdr *) cp;
        if_name = NULL;
        flags = 0;
        adl = NULL;

        if (ifp->ifm_type != RTM_IFINFO)
            continue;

        if (ifp->ifm_addrs & RTA_IFP) {
            a = (struct sockaddr *) (ifp + 1);
            /*
             * if_msghdr is followed by one or more sockaddrs, of which we
             * need only RTA_IFP. most of the time RTA_IFP is the first
             * address we get, hence the shortcut.
             */
            if ((ifp->ifm_addrs & (~RTA_IFP - 1)) != 0) {
                /* skip all addresses up to RTA_IFP. */
                for (amask = (RTA_IFP >> 1); amask != 0; amask >>= 1) {
                    if (ifp->ifm_addrs & amask)
                        a = (struct sockaddr *)
                            ( ((char *) a) + ROUNDUP(a->sa_len) );
                }
            }
            adl = (struct sockaddr_dl *) a;
            if_name = (char *) adl->sdl_data;
            if_name[adl->sdl_nlen] = '\0';
        }
        if (!(ifp->ifm_addrs & RTA_IFP) || if_name == NULL) {
            snmp_log(LOG_ERR, "ifm_index %u: no interface name in message, "
                     "skipping\n", ifp->ifm_index);
            continue;
        }

        entry = netsnmp_access_interface_entry_create(if_name, ifp->ifm_index);
        if(NULL == entry) {
            netsnmp_access_interface_container_free(container,
                                                    NETSNMP_ACCESS_INTERFACE_FREE_NOFLAGS);
            free(if_list);
            return -3;
        }

        /* get physical address */
        if (adl != NULL && adl->sdl_alen > 0) {
            entry->paddr_len = adl->sdl_alen;
            entry->paddr = malloc(entry->paddr_len);
            memcpy(entry->paddr, adl->sdl_data + adl->sdl_nlen, adl->sdl_alen);
            DEBUGMSGTL(("access:interface:container:sysctl",
                        "%s: paddr_len=%d, entry->paddr=%x:%x:%x:%x:%x:%x\n",
                        if_name, entry->paddr_len,
                        entry->paddr[0], entry->paddr[1], entry->paddr[2],
                        entry->paddr[3], entry->paddr[4], entry->paddr[5]));
        } else {
            entry->paddr = malloc(6);
            entry->paddr_len = 6;
            memset(entry->paddr, 0, 6);
        }

        entry->mtu = ifp->ifm_data.ifi_mtu;
        entry->type = ifp->ifm_data.ifi_type;


        entry->ns_flags |= NETSNMP_INTERFACE_FLAGS_HAS_IF_FLAGS;
        entry->os_flags = ifp->ifm_flags;
                
        if (ifp->ifm_flags & IFF_UP) {
            entry->admin_status = IFADMINSTATUS_UP;
#if defined( LINK_STATE_UP ) && defined( LINK_STATE_DOWN )
            if (ifp->ifm_data.ifi_link_state == LINK_STATE_UP) {
                entry->oper_status = IFOPERSTATUS_UP;
            } else if (ifp->ifm_data.ifi_link_state == LINK_STATE_DOWN) {
                entry->oper_status = IFOPERSTATUS_DOWN;
            } else
#endif
            {
                /*
                 * link state is unknown, which is not very useful to report.
                 * use running state instead.
                 */
                entry->oper_status = ifp->ifm_flags & IFF_RUNNING ? 1 : 2;
            }
        } else {
            entry->admin_status = IFADMINSTATUS_DOWN;
            /*
             * IF-MIB specifically says that ifOperStatus should be down in
             * this case
             */
            entry->oper_status = IFOPERSTATUS_DOWN;
        }

        entry->reasm_max_v4 = entry->reasm_max_v6 = IP_MAXPACKET;
        entry->ns_flags |= 
            NETSNMP_INTERFACE_FLAGS_HAS_V4_REASMMAX |
            NETSNMP_INTERFACE_FLAGS_HAS_V6_REASMMAX;

        /* get counters */
        entry->stats.ibytes.low = ifp->ifm_data.ifi_ibytes;
        entry->stats.ibytes.high = 0;
        entry->stats.iucast.low = ifp->ifm_data.ifi_ipackets;
        entry->stats.iucast.high = 0;
        entry->stats.imcast.low = ifp->ifm_data.ifi_imcasts;
        entry->stats.imcast.high = 0;
        entry->stats.ierrors = ifp->ifm_data.ifi_ierrors;
        entry->stats.idiscards = ifp->ifm_data.ifi_iqdrops;
        entry->stats.iunknown_protos = ifp->ifm_data.ifi_noproto;

        entry->stats.obytes.low = ifp->ifm_data.ifi_obytes;
        entry->stats.obytes.high = 0;
        entry->stats.oucast.low = ifp->ifm_data.ifi_opackets;
        entry->stats.oucast.high = 0;
        entry->stats.omcast.low = ifp->ifm_data.ifi_omcasts;
        entry->stats.omcast.high = 0;
        entry->stats.oerrors = ifp->ifm_data.ifi_oerrors;
        entry->ns_flags |=  NETSNMP_INTERFACE_FLAGS_HAS_BYTES |
                            NETSNMP_INTERFACE_FLAGS_HAS_DROPS |
                            NETSNMP_INTERFACE_FLAGS_HAS_MCAST_PKTS;

        if (timercmp(&ifp->ifm_data.ifi_lastchange, &starttime, >)) {
            entry->lastchange = (ifp->ifm_data.ifi_lastchange.tv_sec -
                                 starttime.tv_sec) * 100;
            entry->ns_flags |= NETSNMP_INTERFACE_FLAGS_HAS_LASTCHANGE;
        } else {
            entry->lastchange = 0;
        }

        if (ifp->ifm_flags & ARCH_PROMISC_FLAG)
            entry->promiscuous = 1;

        /* try to guess the speed from media type */
        netsnmp_sysctl_get_if_speed(entry->name, &entry->speed,
                                    &entry->speed_high);
        if (entry->speed_high != 0) {
            entry->ns_flags |= NETSNMP_INTERFACE_FLAGS_HAS_HIGH_SPEED;
        } else {
            /* or resort to ifi_baudrate */
            entry->speed = ifp->ifm_data.ifi_baudrate;
        }

        netsnmp_access_interface_entry_overrides(entry);

        CONTAINER_INSERT(container, entry);
        DEBUGMSGTL(("access:interface:container:sysctl",
                    "created entry %u for %s\n", entry->index, entry->name));
    } /* for (each interface entry) */

    /* pass 2: walk addresses */
    for (cp = if_list; cp < if_list + if_list_size; cp += ifa->ifam_msglen) {

        ifa = (struct ifa_msghdr *) cp;

        if (ifa->ifam_type != RTM_NEWADDR)
            continue;

        DEBUGMSGTL(("access:interface:container:sysctl",
                    "received 0x%x in RTM_NEWADDR for ifindex %u\n",
                    ifa->ifam_addrs, ifa->ifam_index));

        entry = netsnmp_access_interface_entry_get_by_index(container,
                                                            ifa->ifam_index);
        if (entry == NULL) {
            snmp_log(LOG_ERR, "address for a nonexistent interface? index=%d",
                     ifa->ifam_index);
            continue;
        }

        /*
         * walk the list of addresses received. we do not use actual
         * addresses, the sole purpose of this is to set flags
         */
        a = (struct sockaddr *) (ifa + 1);
        for (amask = ifa->ifam_addrs; amask != 0; amask >>= 1) {
            if ((amask & 1) != 0) {
                DEBUGMSGTL(("access:interface:container:sysctl",
                            "%s: a=%p, sa_len=%d, sa_family=0x%x\n",
                            entry->name, a, a->sa_len, a->sa_family));

                if (a->sa_family == AF_INET)
                    entry->ns_flags |= NETSNMP_INTERFACE_FLAGS_HAS_IPV4;
                else if (a->sa_family == AF_INET6)
                    entry->ns_flags |= NETSNMP_INTERFACE_FLAGS_HAS_IPV6;

                a = (struct sockaddr *) ( ((char *) a) + ROUNDUP(a->sa_len) );
            }
        }
        DEBUGMSGTL(("access:interface:container:sysctl",
                    "%s: flags=0x%x\n", entry->name, entry->ns_flags));
    }

    if (if_list != NULL)
        free(if_list);

    return 0;
}

int
netsnmp_arch_set_admin_status(netsnmp_interface_entry * entry,
                              int ifAdminStatus_val)
{
    DEBUGMSGTL(("access:interface:arch", "set_admin_status\n"));

    /* TODO: implement this call */

    /* not implemented */
    snmp_log(LOG_ERR, "netsnmp_arch_set_admin_status not (yet) implemented "
             "for BSD sysctl.\n");

    return -4;
}