snmpudpipv6domain.c

snmp up 2

#include <net-snmp/net-snmp-config.h>

#include <stdio.h>
#include <sys/types.h>
#include <ctype.h>
#include <errno.h>

#if HAVE_STRING_H
#include <string.h>
#else
#include <strings.h>
#endif
#if HAVE_STDLIB_H
#include <stdlib.h>
#endif
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#if HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#if HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#if HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#if HAVE_NETDB_H
#include <netdb.h>
#endif
#if HAVE_NET_IF_H
#include <net/if.h>
#endif

#if HAVE_DMALLOC_H
#include <dmalloc.h>
#endif

#include <net-snmp/types.h>
#include <net-snmp/output_api.h>
#include <net-snmp/config_api.h>

#include <net-snmp/library/snmp_transport.h>
#include <net-snmp/library/snmpUDPIPv6Domain.h>

oid netsnmp_UDPIPv6Domain[10] = { ENTERPRISE_MIB, 3, 3, 4 };
static netsnmp_tdomain udp6Domain;

/*
 * Return a string representing the address in data, or else the "far end"
 * address if data is NULL.  
 */

static char *
netsnmp_udp6_fmtaddr(netsnmp_transport *t, void *data, int len)
{
    struct sockaddr_in6 *to = NULL;

    DEBUGMSGTL(("netsnmp_udp6", "fmtaddr: t = %p, data = %p, len = %d\n", t,
                data, len));
    if (data != NULL && len == sizeof(struct sockaddr_in6)) {
        to = (struct sockaddr_in6 *) data;
    } else if (t != NULL && t->data != NULL) {
        to = (struct sockaddr_in6 *) t->data;
    }
    if (to == NULL) {
        return strdup("UDP/IPv6: unknown");
    } else {
        char addr[INET6_ADDRSTRLEN];
        char tmp[INET6_ADDRSTRLEN + 8];

        sprintf(tmp, "[%s]:%hd",
                inet_ntop(AF_INET6, (void *) &(to->sin6_addr), addr,
                          INET6_ADDRSTRLEN), ntohs(to->sin6_port));
        return strdup(tmp);
    }
}



/*
 * You can write something into opaque that will subsequently get passed back 
 * to your send function if you like.  For instance, you might want to
 * remember where a PDU came from, so that you can send a reply there...  
 */

static int
netsnmp_udp6_recv(netsnmp_transport *t, void *buf, int size,
		  void **opaque, int *olength)
{
    int             rc = -1;
    socklen_t       fromlen = sizeof(struct sockaddr_in6);
    struct sockaddr *from;

    if (t != NULL && t->sock >= 0) {
        from = (struct sockaddr *) malloc(sizeof(struct sockaddr_in6));
        if (from == NULL) {
            *opaque = NULL;
            *olength = 0;
            return -1;
        } else {
            memset(from, 0, fromlen);
        }

	while (rc < 0) {
	  rc = recvfrom(t->sock, buf, size, 0, from, &fromlen);
	  if (rc < 0 && errno != EINTR) {
	    break;
	  }
	}

        if (rc >= 0) {
	    char *string = netsnmp_udp6_fmtaddr(NULL, from, fromlen);
            DEBUGMSGTL(("netsnmp_udp6",
			"recvfrom fd %d got %d bytes (from %s)\n", t->sock,
                        rc, string));
            free(string);
        } else {
            DEBUGMSGTL(("netsnmp_udp6", "recvfrom fd %d err %d (\"%s\")\n",
			t->sock, errno, strerror(errno)));
        }
        *opaque = (void *) from;
        *olength = sizeof(struct sockaddr_in6);
    }
    return rc;
}



static int
netsnmp_udp6_send(netsnmp_transport *t, void *buf, int size,
		  void **opaque, int *olength)
{
    int rc = -1;
    struct sockaddr *to = NULL;

    if (opaque != NULL && *opaque != NULL &&
        *olength == sizeof(struct sockaddr_in6)) {
        to = (struct sockaddr *) (*opaque);
    } else if (t != NULL && t->data != NULL &&
               t->data_length == sizeof(struct sockaddr_in6)) {
        to = (struct sockaddr *) (t->data);
    }

    if (to != NULL && t != NULL && t->sock >= 0) {
        char *string = netsnmp_udp6_fmtaddr(NULL, (void *)to,
					    sizeof(struct sockaddr_in6));
        DEBUGMSGTL(("netsnmp_udp6", "send %d bytes from %p to %s on fd %d\n",
                    size, buf, string, t->sock));
        free(string);
	while (rc < 0) {
	    rc = sendto(t->sock, buf, size, 0, to,sizeof(struct sockaddr_in6));
	    if (rc < 0 && errno != EINTR) {
		break;
	    }
	}
    }
    return rc;
}



static int
netsnmp_udp6_close(netsnmp_transport *t)
{
    int rc = -1;
    if (t != NULL && t->sock >= 0) {
        DEBUGMSGTL(("netsnmp_udp6", "close fd %d\n", t->sock));
#ifndef HAVE_CLOSESOCKET
        rc = close(t->sock);
#else
        rc = closesocket(t->sock);
#endif
        t->sock = -1;
    }
    return rc;
}



/*
 * Open a UDP/IPv6-based transport for SNMP.  Local is TRUE if addr is the
 * local address to bind to (i.e. this is a server-type session); otherwise
 * addr is the remote address to send things to.  
 */

netsnmp_transport *
netsnmp_udp6_transport(struct sockaddr_in6 *addr, int local)
{
    netsnmp_transport *t = NULL;
    int             rc = 0, udpbuf = (1 << 17);
    char           *string = NULL;

    if (addr == NULL || addr->sin6_family != AF_INET6) {
        return NULL;
    }

    t = (netsnmp_transport *) malloc(sizeof(netsnmp_transport));
    if (t == NULL) {
        return NULL;
    }

    string = netsnmp_udp6_fmtaddr(NULL, (void *) addr,
				  sizeof(struct sockaddr_in6));
    DEBUGMSGTL(("netsnmp_udp6", "open %s %s\n", local ? "local" : "remote",
                string));
    free(string);

    memset(t, 0, sizeof(netsnmp_transport));

    t->domain = netsnmp_UDPIPv6Domain;
    t->domain_length =
        sizeof(netsnmp_UDPIPv6Domain) / sizeof(netsnmp_UDPIPv6Domain[0]);

    t->sock = socket(PF_INET6, SOCK_DGRAM, 0);
    if (t->sock < 0) {
        netsnmp_transport_free(t);
        return NULL;
    }
#ifdef  SO_BSDCOMPAT
    /*
     * Patch for Linux.  Without this, UDP packets that fail get an ICMP
     * response.  Linux turns the failed ICMP response into an error message
     * and return value, unlike all other OS's.  
     */
    {
        int             one = 1;
        setsockopt(t->sock, SOL_SOCKET, SO_BSDCOMPAT, &one, sizeof(one));
    }
#endif                          /*SO_BSDCOMPAT */

    /*
     * Try to set the send and receive buffers to a reasonably large value, so
     * that we can send and receive big PDUs (defaults to 8192 bytes (!) on
     * Solaris, for instance).  Don't worry too much about errors -- just
     * plough on regardless.  
     */

#ifdef  SO_SNDBUF
    if (setsockopt(t->sock, SOL_SOCKET, SO_SNDBUF, &udpbuf, sizeof(int)) != 0){
        DEBUGMSGTL(("netsnmp_udp6", "couldn't set SO_SNDBUF to %d bytes: %s\n",
		    udpbuf, strerror(errno)));
    }
#endif                          /*SO_SNDBUF */

#ifdef  SO_RCVBUF
    if (setsockopt(t->sock, SOL_SOCKET, SO_RCVBUF, &udpbuf, sizeof(int)) != 0){
        DEBUGMSGTL(("netsnmp_udp6", "couldn't set SO_RCVBUF to %d bytes: %s\n",
		    udpbuf, strerror(errno)));
    }
#endif                          /*SO_RCVBUF */

    if (local) {
        /*
         * This session is inteneded as a server, so we must bind on to the
         * given IP address, which may include an interface address, or could
         * be INADDR_ANY, but certainly includes a port number.
         */

#ifdef IPV6_V6ONLY
        /* Try to restrict PF_INET6 socket to IPv6 communications only. */
        {
	  int one=1;
	  if (setsockopt(t->sock, IPPROTO_IPV6, IPV6_V6ONLY, (char *)&one, sizeof(one)) != 0) {
	    DEBUGMSGTL(("netsnmp_udp6", "couldn't set IPV6_V6ONLY to %d bytes: %s\n", one, strerror(errno)));
	  } 
	}
#endif

        rc = bind(t->sock, (struct sockaddr *) addr,
		  sizeof(struct sockaddr_in6));
        if (rc != 0) {
            netsnmp_udp6_close(t);
            netsnmp_transport_free(t);
            return NULL;
        }
        t->local = malloc(18);
        if (t->local == NULL) {
            netsnmp_udp6_close(t);
            netsnmp_transport_free(t);
        }
        memcpy(t->local, addr->sin6_addr.s6_addr, 16);
        t->local[16] = (addr->sin6_port & 0xff00) >> 8;
        t->local[17] = (addr->sin6_port & 0x00ff) >> 0;
        t->local_length = 18;
        t->data = NULL;
        t->data_length = 0;
    } else {
        /*
         * This is a client session.  Save the address in the
         * transport-specific data pointer for later use by netsnmp_udp6_send.
         */

        t->data = malloc(sizeof(struct sockaddr_in6));
        if (t->data == NULL) {
            netsnmp_transport_free(t);
            return NULL;
        }
        memcpy(t->data, addr, sizeof(struct sockaddr_in6));
        t->data_length = sizeof(struct sockaddr_in6);
        t->remote = malloc(18);
        if (t->remote == NULL) {
            netsnmp_udp6_close(t);
            netsnmp_transport_free(t);
            return NULL;
        }
        memcpy(t->remote, addr->sin6_addr.s6_addr, 16);
        t->remote[16] = (addr->sin6_port & 0xff00) >> 8;
        t->remote[17] = (addr->sin6_port & 0x00ff) >> 0;
        t->remote_length = 18;
    }

    /*
     * 16-bit length field, 8 byte UDP header, 40 byte IPv6 header.  
     */

    t->msgMaxSize = 0xffff - 8 - 40;
    t->f_recv     = netsnmp_udp6_recv;
    t->f_send     = netsnmp_udp6_send;
    t->f_close    = netsnmp_udp6_close;
    t->f_accept   = NULL;
    t->f_fmtaddr  = netsnmp_udp6_fmtaddr;

    return t;
}



int
netsnmp_sockaddr_in6(struct sockaddr_in6 *addr,
                     const char *inpeername, int remote_port)
{
    char           *cp = NULL, *peername = NULL;
    char            debug_addr[INET6_ADDRSTRLEN];
#if HAVE_GETADDRINFO
    struct addrinfo *addrs = NULL;
    struct addrinfo hint;
    int             err;
#elif HAVE_GETIPNODEBYNAME
    struct hostent *hp = NULL;
    int             err;
#elif HAVE_GETHOSTBYNAME
    struct hostent *hp = NULL;
#endif

    if (addr == NULL) {
        return 0;
    }

    DEBUGMSGTL(("netsnmp_sockaddr_in6", "addr %p, peername \"%s\"\n",
                addr, inpeername ? inpeername : "[NIL]"));

    memset(addr, 0, sizeof(struct sockaddr_in6));
    addr->sin6_family = AF_INET6;
    addr->sin6_addr = in6addr_any;

    if (remote_port > 0) {
        addr->sin6_port = htons(remote_port);
    } else if (netsnmp_ds_get_int(NETSNMP_DS_LIBRARY_ID, 
				  NETSNMP_DS_LIB_DEFAULT_PORT) > 0) {
        addr->sin6_port = htons(netsnmp_ds_get_int(NETSNMP_DS_LIBRARY_ID, 
						 NETSNMP_DS_LIB_DEFAULT_PORT));
    } else {
        addr->sin6_port = htons(SNMP_PORT);
    }

    if (inpeername != NULL) {
        /*
         * Duplicate the peername because we might want to mank around with
         * it.  
         */

        peername = strdup(inpeername);
        if (peername == NULL) {
            return 0;
        }

        for (cp = peername; *cp && isdigit((int) *cp); cp++);
        if (!*cp && atoi(peername) != 0) {
            /*
             * Okay, it looks like JUST a port number.  
             */
            DEBUGMSGTL(("netsnmp_sockaddr_in6", "totally numeric: %d\n",
                        atoi(peername)));
            addr->sin6_port = htons(atoi(peername));
            goto resolved;
        }

        /*
         * See if it is an IPv6 address, which covered with square brankets
         * with an appended :port.  
         */
        if (*peername == '[') {
            cp = strchr(peername, ']');
            if (cp != NULL) {
	      /*
	       * See if it is an IPv6 link-local address with interface
	       * name as <zone_id>, like fe80::1234%eth0.
	       * Please refer to the internet draft, IPv6 Scoped Address Architecture
	       * http://www.ietf.org/internet-drafts/draft-ietf-ipngwg-scoping-arch-04.txt
	       *
	       */
	        char *scope_id;
		unsigned int if_index = 0;
                *cp = '\0';
		scope_id = strchr(peername + 1, '%');
		if (scope_id != NULL) {
		    *scope_id = '\0';
		    if_index = if_nametoindex(scope_id + 1);
		}
                if (*(cp + 1) == ':') {
                    if (atoi(cp + 2) != 0 &&
                        inet_pton(AF_INET6, peername + 1,
                                  (void *) &(addr->sin6_addr))) {
                        DEBUGMSGTL(("netsnmp_sockaddr_in6",
                                    "IPv6 address with port suffix :%d\n",
                                    atoi(cp + 2)));
                        addr->sin6_port = htons(atoi(cp + 2));
			addr->sin6_scope_id = if_index;
                        goto resolved;
                    }
                } else {