open_socket_out is always used with SOCK_STREAM, remove argument "type"

[Samba/gebeck_regimport.git] / source3 / lib / util_sock.c

/*
   Unix SMB/CIFS implementation.
   Samba utility functions
   Copyright (C) Andrew Tridgell 1992-1998
   Copyright (C) Tim Potter      2000-2001
   Copyright (C) Jeremy Allison  1992-2007

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"

/*******************************************************************
 Map a text hostname or IP address (IPv4 or IPv6) into a
 struct sockaddr_storage.
******************************************************************/

bool interpret_string_addr(struct sockaddr_storage *pss,
                const char *str,
                int flags)
{
        struct addrinfo *res = NULL;
#if defined(HAVE_IPV6)
        char addr[INET6_ADDRSTRLEN];
        unsigned int scope_id = 0;

        if (strchr_m(str, ':')) {
                char *p = strchr_m(str, '%');

                /*
                 * Cope with link-local.
                 * This is IP:v6:addr%ifname.
                 */

                if (p && (p > str) && ((scope_id = if_nametoindex(p+1)) != 0)) {
                        strlcpy(addr, str,
                                MIN(PTR_DIFF(p,str)+1,
                                        sizeof(addr)));
                        str = addr;
                }
        }
#endif

        zero_sockaddr(pss);

        if (!interpret_string_addr_internal(&res, str, flags|AI_ADDRCONFIG)) {
                return false;
        }
        if (!res) {
                return false;
        }
        /* Copy the first sockaddr. */
        memcpy(pss, res->ai_addr, res->ai_addrlen);

#if defined(HAVE_IPV6)
        if (pss->ss_family == AF_INET6 && scope_id) {
                struct sockaddr_in6 *ps6 = (struct sockaddr_in6 *)pss;
                if (IN6_IS_ADDR_LINKLOCAL(&ps6->sin6_addr) &&
                                ps6->sin6_scope_id == 0) {
                        ps6->sin6_scope_id = scope_id;
                }
        }
#endif

        freeaddrinfo(res);
        return true;
}

/*******************************************************************
 Set an address to INADDR_ANY.
******************************************************************/

void zero_sockaddr(struct sockaddr_storage *pss)
{
        memset(pss, '\0', sizeof(*pss));
        /* Ensure we're at least a valid sockaddr-storage. */
        pss->ss_family = AF_INET;
}

/****************************************************************************
 Get a port number in host byte order from a sockaddr_storage.
****************************************************************************/

uint16_t get_sockaddr_port(const struct sockaddr_storage *pss)
{
        uint16_t port = 0;

        if (pss->ss_family != AF_INET) {
#if defined(HAVE_IPV6)
                /* IPv6 */
                const struct sockaddr_in6 *sa6 =
                        (const struct sockaddr_in6 *)pss;
                port = ntohs(sa6->sin6_port);
#endif
        } else {
                const struct sockaddr_in *sa =
                        (const struct sockaddr_in *)pss;
                port = ntohs(sa->sin_port);
        }
        return port;
}

/****************************************************************************
 Print out an IPv4 or IPv6 address from a struct sockaddr_storage.
****************************************************************************/

static char *print_sockaddr_len(char *dest,
                        size_t destlen,
                        const struct sockaddr *psa,
                        socklen_t psalen)
{
        if (destlen > 0) {
                dest[0] = '\0';
        }
        (void)sys_getnameinfo(psa,
                        psalen,
                        dest, destlen,
                        NULL, 0,
                        NI_NUMERICHOST);
        return dest;
}

/****************************************************************************
 Print out an IPv4 or IPv6 address from a struct sockaddr_storage.
****************************************************************************/

char *print_sockaddr(char *dest,
                        size_t destlen,
                        const struct sockaddr_storage *psa)
{
        return print_sockaddr_len(dest, destlen, (struct sockaddr *)psa,
                        sizeof(struct sockaddr_storage));
}

/****************************************************************************
 Print out a canonical IPv4 or IPv6 address from a struct sockaddr_storage.
****************************************************************************/

char *print_canonical_sockaddr(TALLOC_CTX *ctx,
                        const struct sockaddr_storage *pss)
{
        char addr[INET6_ADDRSTRLEN];
        char *dest = NULL;
        int ret;

        /* Linux getnameinfo() man pages says port is unitialized if
           service name is NULL. */

        ret = sys_getnameinfo((const struct sockaddr *)pss,
                        sizeof(struct sockaddr_storage),
                        addr, sizeof(addr),
                        NULL, 0,
                        NI_NUMERICHOST);
        if (ret != 0) {
                return NULL;
        }

        if (pss->ss_family != AF_INET) {
#if defined(HAVE_IPV6)
                dest = talloc_asprintf(ctx, "[%s]", addr);
#else
                return NULL;
#endif
        } else {
                dest = talloc_asprintf(ctx, "%s", addr);
        }
        
        return dest;
}

/****************************************************************************
 Return the string of an IP address (IPv4 or IPv6).
****************************************************************************/

static const char *get_socket_addr(int fd, char *addr_buf, size_t addr_len)
{
        struct sockaddr_storage sa;
        socklen_t length = sizeof(sa);

        /* Ok, returning a hard coded IPv4 address
         * is bogus, but it's just as bogus as a
         * zero IPv6 address. No good choice here.
         */

        strlcpy(addr_buf, "0.0.0.0", addr_len);

        if (fd == -1) {
                return addr_buf;
        }

        if (getsockname(fd, (struct sockaddr *)&sa, &length) < 0) {
                DEBUG(0,("getsockname failed. Error was %s\n",
                        strerror(errno) ));
                return addr_buf;
        }

        return print_sockaddr_len(addr_buf, addr_len, (struct sockaddr *)&sa, length);
}

#if 0
/* Not currently used. JRA. */
/****************************************************************************
 Return the port number we've bound to on a socket.
****************************************************************************/

static int get_socket_port(int fd)
{
        struct sockaddr_storage sa;
        socklen_t length = sizeof(sa);

        if (fd == -1) {
                return -1;
        }

        if (getsockname(fd, (struct sockaddr *)&sa, &length) < 0) {
                DEBUG(0,("getpeername failed. Error was %s\n",
                        strerror(errno) ));
                return -1;
        }

#if defined(HAVE_IPV6)
        if (sa.ss_family == AF_INET6) {
                return ntohs(((struct sockaddr_in6 *)&sa)->sin6_port);
        }
#endif
        if (sa.ss_family == AF_INET) {
                return ntohs(((struct sockaddr_in *)&sa)->sin_port);
        }
        return -1;
}
#endif

const char *client_name(int fd)
{
        return get_peer_name(fd,false);
}

const char *client_addr(int fd, char *addr, size_t addrlen)
{
        return get_peer_addr(fd,addr,addrlen);
}

const char *client_socket_addr(int fd, char *addr, size_t addr_len)
{
        return get_socket_addr(fd, addr, addr_len);
}

#if 0
/* Not currently used. JRA. */
int client_socket_port(int fd)
{
        return get_socket_port(fd);
}
#endif

/****************************************************************************
 Accessor functions to make thread-safe code easier later...
****************************************************************************/

void set_smb_read_error(enum smb_read_errors *pre,
                        enum smb_read_errors newerr)
{
        if (pre) {
                *pre = newerr;
        }
}

void cond_set_smb_read_error(enum smb_read_errors *pre,
                        enum smb_read_errors newerr)
{
        if (pre && *pre == SMB_READ_OK) {
                *pre = newerr;
        }
}

/****************************************************************************
 Determine if a file descriptor is in fact a socket.
****************************************************************************/

bool is_a_socket(int fd)
{
        int v;
        socklen_t l;
        l = sizeof(int);
        return(getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&v, &l) == 0);
}

enum SOCK_OPT_TYPES {OPT_BOOL,OPT_INT,OPT_ON};

typedef struct smb_socket_option {
        const char *name;
        int level;
        int option;
        int value;
        int opttype;
} smb_socket_option;

static const smb_socket_option socket_options[] = {
  {"SO_KEEPALIVE", SOL_SOCKET, SO_KEEPALIVE, 0, OPT_BOOL},
  {"SO_REUSEADDR", SOL_SOCKET, SO_REUSEADDR, 0, OPT_BOOL},
  {"SO_BROADCAST", SOL_SOCKET, SO_BROADCAST, 0, OPT_BOOL},
#ifdef TCP_NODELAY
  {"TCP_NODELAY", IPPROTO_TCP, TCP_NODELAY, 0, OPT_BOOL},
#endif
#ifdef TCP_KEEPCNT
  {"TCP_KEEPCNT", IPPROTO_TCP, TCP_KEEPCNT, 0, OPT_INT},
#endif
#ifdef TCP_KEEPIDLE
  {"TCP_KEEPIDLE", IPPROTO_TCP, TCP_KEEPIDLE, 0, OPT_INT},
#endif
#ifdef TCP_KEEPINTVL
  {"TCP_KEEPINTVL", IPPROTO_TCP, TCP_KEEPINTVL, 0, OPT_INT},
#endif
#ifdef IPTOS_LOWDELAY
  {"IPTOS_LOWDELAY", IPPROTO_IP, IP_TOS, IPTOS_LOWDELAY, OPT_ON},
#endif
#ifdef IPTOS_THROUGHPUT
  {"IPTOS_THROUGHPUT", IPPROTO_IP, IP_TOS, IPTOS_THROUGHPUT, OPT_ON},
#endif
#ifdef SO_REUSEPORT
  {"SO_REUSEPORT", SOL_SOCKET, SO_REUSEPORT, 0, OPT_BOOL},
#endif
#ifdef SO_SNDBUF
  {"SO_SNDBUF", SOL_SOCKET, SO_SNDBUF, 0, OPT_INT},
#endif
#ifdef SO_RCVBUF
  {"SO_RCVBUF", SOL_SOCKET, SO_RCVBUF, 0, OPT_INT},
#endif
#ifdef SO_SNDLOWAT
  {"SO_SNDLOWAT", SOL_SOCKET, SO_SNDLOWAT, 0, OPT_INT},
#endif
#ifdef SO_RCVLOWAT
  {"SO_RCVLOWAT", SOL_SOCKET, SO_RCVLOWAT, 0, OPT_INT},
#endif
#ifdef SO_SNDTIMEO
  {"SO_SNDTIMEO", SOL_SOCKET, SO_SNDTIMEO, 0, OPT_INT},
#endif
#ifdef SO_RCVTIMEO
  {"SO_RCVTIMEO", SOL_SOCKET, SO_RCVTIMEO, 0, OPT_INT},
#endif
#ifdef TCP_FASTACK
  {"TCP_FASTACK", IPPROTO_TCP, TCP_FASTACK, 0, OPT_INT},
#endif
  {NULL,0,0,0,0}};

/****************************************************************************
 Print socket options.
****************************************************************************/

static void print_socket_options(int s)
{
        int value;
        socklen_t vlen = 4;
        const smb_socket_option *p = &socket_options[0];

        /* wrapped in if statement to prevent streams
         * leak in SCO Openserver 5.0 */
        /* reported on samba-technical  --jerry */
        if ( DEBUGLEVEL >= 5 ) {
                DEBUG(5,("Socket options:\n"));
                for (; p->name != NULL; p++) {
                        if (getsockopt(s, p->level, p->option,
                                                (void *)&value, &vlen) == -1) {
                                DEBUGADD(5,("\tCould not test socket option %s.\n",
                                                        p->name));
                        } else {
                                DEBUGADD(5,("\t%s = %d\n",
                                                        p->name,value));
                        }
                }
        }
 }

/****************************************************************************
 Set user socket options.
****************************************************************************/

void set_socket_options(int fd, const char *options)
{
        TALLOC_CTX *ctx = talloc_stackframe();
        char *tok;

        while (next_token_talloc(ctx, &options, &tok," \t,")) {
                int ret=0,i;
                int value = 1;
                char *p;
                bool got_value = false;

                if ((p = strchr_m(tok,'='))) {
                        *p = 0;
                        value = atoi(p+1);
                        got_value = true;
                }

                for (i=0;socket_options[i].name;i++)
                        if (strequal(socket_options[i].name,tok))
                                break;

                if (!socket_options[i].name) {
                        DEBUG(0,("Unknown socket option %s\n",tok));
                        continue;
                }

                switch (socket_options[i].opttype) {
                case OPT_BOOL:
                case OPT_INT:
                        ret = setsockopt(fd,socket_options[i].level,
                                        socket_options[i].option,
                                        (char *)&value,sizeof(int));
                        break;

                case OPT_ON:
                        if (got_value)
                                DEBUG(0,("syntax error - %s "
                                        "does not take a value\n",tok));

                        {
                                int on = socket_options[i].value;
                                ret = setsockopt(fd,socket_options[i].level,
                                        socket_options[i].option,
                                        (char *)&on,sizeof(int));
                        }
                        break;
                }

                if (ret != 0) {
                        /* be aware that some systems like Solaris return
                         * EINVAL to a setsockopt() call when the client
                         * sent a RST previously - no need to worry */
                        DEBUG(2,("Failed to set socket option %s (Error %s)\n",
                                tok, strerror(errno) ));
                }
        }

        TALLOC_FREE(ctx);
        print_socket_options(fd);
}

/****************************************************************************
 Read from a socket.
****************************************************************************/

ssize_t read_udp_v4_socket(int fd,
                        char *buf,
                        size_t len,
                        struct sockaddr_storage *psa)
{
        ssize_t ret;
        socklen_t socklen = sizeof(*psa);
        struct sockaddr_in *si = (struct sockaddr_in *)psa;

        memset((char *)psa,'\0',socklen);

        ret = (ssize_t)sys_recvfrom(fd,buf,len,0,
                        (struct sockaddr *)psa,&socklen);
        if (ret <= 0) {
                /* Don't print a low debug error for a non-blocking socket. */
                if (errno == EAGAIN) {
                        DEBUG(10,("read_udp_v4_socket: returned EAGAIN\n"));
                } else {
                        DEBUG(2,("read_udp_v4_socket: failed. errno=%s\n",
                                strerror(errno)));
                }
                return 0;
        }

        if (psa->ss_family != AF_INET) {
                DEBUG(2,("read_udp_v4_socket: invalid address family %d "
                        "(not IPv4)\n", (int)psa->ss_family));
                return 0;
        }

        DEBUG(10,("read_udp_v4_socket: ip %s port %d read: %lu\n",
                        inet_ntoa(si->sin_addr),
                        si->sin_port,
                        (unsigned long)ret));

        return ret;
}

/****************************************************************************
 Read data from a socket with a timout in msec.
 mincount = if timeout, minimum to read before returning
 maxcount = number to be read.
 time_out = timeout in milliseconds
****************************************************************************/

NTSTATUS read_socket_with_timeout(int fd, char *buf,
                                  size_t mincnt, size_t maxcnt,
                                  unsigned int time_out,
                                  size_t *size_ret)
{
        fd_set fds;
        int selrtn;
        ssize_t readret;
        size_t nread = 0;
        struct timeval timeout;
        char addr[INET6_ADDRSTRLEN];

        /* just checking .... */
        if (maxcnt <= 0)
                return NT_STATUS_OK;

        /* Blocking read */
        if (time_out == 0) {
                if (mincnt == 0) {
                        mincnt = maxcnt;
                }

                while (nread < mincnt) {
                        readret = sys_read(fd, buf + nread, maxcnt - nread);

                        if (readret == 0) {
                                DEBUG(5,("read_socket_with_timeout: "
                                        "blocking read. EOF from client.\n"));
                                return NT_STATUS_END_OF_FILE;
                        }

                        if (readret == -1) {
                                if (fd == get_client_fd()) {
                                        /* Try and give an error message
                                         * saying what client failed. */
                                        DEBUG(0,("read_socket_with_timeout: "
                                                "client %s read error = %s.\n",
                                                get_peer_addr(fd,addr,sizeof(addr)),
                                                strerror(errno) ));
                                } else {
                                        DEBUG(0,("read_socket_with_timeout: "
                                                "read error = %s.\n",
                                                strerror(errno) ));
                                }
                                return map_nt_error_from_unix(errno);
                        }
                        nread += readret;
                }
                goto done;
        }

        /* Most difficult - timeout read */
        /* If this is ever called on a disk file and
           mincnt is greater then the filesize then
           system performance will suffer severely as
           select always returns true on disk files */

        /* Set initial timeout */
        timeout.tv_sec = (time_t)(time_out / 1000);
        timeout.tv_usec = (long)(1000 * (time_out % 1000));

        for (nread=0; nread < mincnt; ) {
                FD_ZERO(&fds);
                FD_SET(fd,&fds);

                selrtn = sys_select_intr(fd+1,&fds,NULL,NULL,&timeout);

                /* Check if error */
                if (selrtn == -1) {
                        /* something is wrong. Maybe the socket is dead? */
                        if (fd == get_client_fd()) {
                                /* Try and give an error message saying
                                 * what client failed. */
                                DEBUG(0,("read_socket_with_timeout: timeout "
                                "read for client %s. select error = %s.\n",
                                get_peer_addr(fd,addr,sizeof(addr)),
                                strerror(errno) ));
                        } else {
                                DEBUG(0,("read_socket_with_timeout: timeout "
                                "read. select error = %s.\n",
                                strerror(errno) ));
                        }
                        return map_nt_error_from_unix(errno);
                }

                /* Did we timeout ? */
                if (selrtn == 0) {
                        DEBUG(10,("read_socket_with_timeout: timeout read. "
                                "select timed out.\n"));
                        return NT_STATUS_IO_TIMEOUT;
                }

                readret = sys_read(fd, buf+nread, maxcnt-nread);

                if (readret == 0) {
                        /* we got EOF on the file descriptor */
                        DEBUG(5,("read_socket_with_timeout: timeout read. "
                                "EOF from client.\n"));
                        return NT_STATUS_END_OF_FILE;
                }

                if (readret == -1) {
                        /* the descriptor is probably dead */
                        if (fd == get_client_fd()) {
                                /* Try and give an error message
                                 * saying what client failed. */
                                DEBUG(0,("read_socket_with_timeout: timeout "
                                        "read to client %s. read error = %s.\n",
                                        get_peer_addr(fd,addr,sizeof(addr)),
                                        strerror(errno) ));
                        } else {
                                DEBUG(0,("read_socket_with_timeout: timeout "
                                        "read. read error = %s.\n",
                                        strerror(errno) ));
                        }
                        return map_nt_error_from_unix(errno);
                }

                nread += readret;
        }

 done:
        /* Return the number we got */
        if (size_ret) {
                *size_ret = nread;
        }
        return NT_STATUS_OK;
}

/****************************************************************************
 Read data from the client, reading exactly N bytes.
****************************************************************************/

NTSTATUS read_data(int fd, char *buffer, size_t N)
{
        return read_socket_with_timeout(fd, buffer, N, N, 0, NULL);
}

/****************************************************************************
 Write all data from an iov array
****************************************************************************/

ssize_t write_data_iov(int fd, const struct iovec *orig_iov, int iovcnt)
{
        int i;
        size_t to_send;
        ssize_t thistime;
        size_t sent;
        struct iovec *iov_copy, *iov;

        to_send = 0;
        for (i=0; i<iovcnt; i++) {
                to_send += orig_iov[i].iov_len;
        }

        thistime = sys_writev(fd, orig_iov, iovcnt);
        if ((thistime <= 0) || (thistime == to_send)) {
                return thistime;
        }
        sent = thistime;

        /*
         * We could not send everything in one call. Make a copy of iov that
         * we can mess with. We keep a copy of the array start in iov_copy for
         * the TALLOC_FREE, because we're going to modify iov later on,
         * discarding elements.
         */

        iov_copy = (struct iovec *)TALLOC_MEMDUP(
                talloc_tos(), orig_iov, sizeof(struct iovec) * iovcnt);

        if (iov_copy == NULL) {
                errno = ENOMEM;
                return -1;
        }
        iov = iov_copy;

        while (sent < to_send) {
                /*
                 * We have to discard "thistime" bytes from the beginning
                 * iov array, "thistime" contains the number of bytes sent
                 * via writev last.
                 */
                while (thistime > 0) {
                        if (thistime < iov[0].iov_len) {
                                char *new_base =
                                        (char *)iov[0].iov_base + thistime;
                                iov[0].iov_base = new_base;
                                iov[0].iov_len -= thistime;
                                break;
                        }
                        thistime -= iov[0].iov_len;
                        iov += 1;
                        iovcnt -= 1;
                }

                thistime = sys_writev(fd, iov, iovcnt);
                if (thistime <= 0) {
                        break;
                }
                sent += thistime;
        }

        TALLOC_FREE(iov_copy);
        return sent;
}

/****************************************************************************
 Write data to a fd.
****************************************************************************/

/****************************************************************************
 Write data to a fd.
****************************************************************************/

ssize_t write_data(int fd, const char *buffer, size_t N)
{
        ssize_t ret;
        struct iovec iov;

        iov.iov_base = CONST_DISCARD(char *, buffer);
        iov.iov_len = N;

        ret = write_data_iov(fd, &iov, 1);
        if (ret >= 0) {
                return ret;
        }

        if (fd == get_client_fd()) {
                char addr[INET6_ADDRSTRLEN];
                /*
                 * Try and give an error message saying what client failed.
                 */
                DEBUG(0, ("write_data: write failure in writing to client %s. "
                          "Error %s\n", get_peer_addr(fd,addr,sizeof(addr)),
                          strerror(errno)));
        } else {
                DEBUG(0,("write_data: write failure. Error = %s\n",
                         strerror(errno) ));
        }

        return -1;
}

/****************************************************************************
 Send a keepalive packet (rfc1002).
****************************************************************************/

bool send_keepalive(int client)
{
        unsigned char buf[4];

        buf[0] = SMBkeepalive;
        buf[1] = buf[2] = buf[3] = 0;

        return(write_data(client,(char *)buf,4) == 4);
}

/****************************************************************************
 Read 4 bytes of a smb packet and return the smb length of the packet.
 Store the result in the buffer.
 This version of the function will return a length of zero on receiving
 a keepalive packet.
 Timeout is in milliseconds.
****************************************************************************/

NTSTATUS read_smb_length_return_keepalive(int fd, char *inbuf,
                                          unsigned int timeout,
                                          size_t *len)
{
        int msg_type;
        NTSTATUS status;

        status = read_socket_with_timeout(fd, inbuf, 4, 4, timeout, NULL);

        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }

        *len = smb_len(inbuf);
        msg_type = CVAL(inbuf,0);

        if (msg_type == SMBkeepalive) {
                DEBUG(5,("Got keepalive packet\n"));
        }

        DEBUG(10,("got smb length of %lu\n",(unsigned long)(*len)));

        return NT_STATUS_OK;
}

/****************************************************************************
 Read 4 bytes of a smb packet and return the smb length of the packet.
 Store the result in the buffer. This version of the function will
 never return a session keepalive (length of zero).
 Timeout is in milliseconds.
****************************************************************************/

NTSTATUS read_smb_length(int fd, char *inbuf, unsigned int timeout,
                         size_t *len)
{
        uint8_t msgtype = SMBkeepalive;

        while (msgtype == SMBkeepalive) {
                NTSTATUS status;

                status = read_smb_length_return_keepalive(fd, inbuf, timeout,
                                                          len);
                if (!NT_STATUS_IS_OK(status)) {
                        return status;
                }

                msgtype = CVAL(inbuf, 0);
        }

        DEBUG(10,("read_smb_length: got smb length of %lu\n",
                  (unsigned long)len));

        return NT_STATUS_OK;
}

/****************************************************************************
 Read an smb from a fd.
 The timeout is in milliseconds.
 This function will return on receipt of a session keepalive packet.
 maxlen is the max number of bytes to return, not including the 4 byte
 length. If zero it means buflen limit.
 Doesn't check the MAC on signed packets.
****************************************************************************/

NTSTATUS receive_smb_raw(int fd, char *buffer, size_t buflen, unsigned int timeout,
                         size_t maxlen, size_t *p_len)
{
        size_t len;
        NTSTATUS status;

        status = read_smb_length_return_keepalive(fd,buffer,timeout,&len);

        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(10, ("receive_smb_raw: %s!\n", nt_errstr(status)));
                return status;
        }

        if (len > buflen) {
                DEBUG(0,("Invalid packet length! (%lu bytes).\n",
                                        (unsigned long)len));
                return NT_STATUS_INVALID_PARAMETER;
        }

        if(len > 0) {
                if (maxlen) {
                        len = MIN(len,maxlen);
                }

                status = read_socket_with_timeout(
                        fd, buffer+4, len, len, timeout, &len);

                if (!NT_STATUS_IS_OK(status)) {
                        return status;
                }

                /* not all of samba3 properly checks for packet-termination
                 * of strings. This ensures that we don't run off into
                 * empty space. */
                SSVAL(buffer+4,len, 0);
        }

        *p_len = len;
        return NT_STATUS_OK;
}

/****************************************************************************
 Open a socket of the specified type, port, and address for incoming data.
****************************************************************************/

int open_socket_in(int type,
                uint16_t port,
                int dlevel,
                const struct sockaddr_storage *psock,
                bool rebind)
{
        struct sockaddr_storage sock;
        int res;
        socklen_t slen = sizeof(struct sockaddr_in);

        sock = *psock;

#if defined(HAVE_IPV6)
        if (sock.ss_family == AF_INET6) {
                ((struct sockaddr_in6 *)&sock)->sin6_port = htons(port);
                slen = sizeof(struct sockaddr_in6);
        }
#endif
        if (sock.ss_family == AF_INET) {
                ((struct sockaddr_in *)&sock)->sin_port = htons(port);
        }

        res = socket(sock.ss_family, type, 0 );
        if( res == -1 ) {
                if( DEBUGLVL(0) ) {
                        dbgtext( "open_socket_in(): socket() call failed: " );
                        dbgtext( "%s\n", strerror( errno ) );
                }
                return -1;
        }

        /* This block sets/clears the SO_REUSEADDR and possibly SO_REUSEPORT. */
        {
                int val = rebind ? 1 : 0;
                if( setsockopt(res,SOL_SOCKET,SO_REUSEADDR,
                                        (char *)&val,sizeof(val)) == -1 ) {
                        if( DEBUGLVL( dlevel ) ) {
                                dbgtext( "open_socket_in(): setsockopt: " );
                                dbgtext( "SO_REUSEADDR = %s ",
                                                val?"true":"false" );
                                dbgtext( "on port %d failed ", port );
                                dbgtext( "with error = %s\n", strerror(errno) );
                        }
                }
#ifdef SO_REUSEPORT
                if( setsockopt(res,SOL_SOCKET,SO_REUSEPORT,
                                        (char *)&val,sizeof(val)) == -1 ) {
                        if( DEBUGLVL( dlevel ) ) {
                                dbgtext( "open_socket_in(): setsockopt: ");
                                dbgtext( "SO_REUSEPORT = %s ",
                                                val?"true":"false");
                                dbgtext( "on port %d failed ", port);
                                dbgtext( "with error = %s\n", strerror(errno));
                        }
                }
#endif /* SO_REUSEPORT */
        }

        /* now we've got a socket - we need to bind it */
        if (bind(res, (struct sockaddr *)&sock, slen) == -1 ) {
                if( DEBUGLVL(dlevel) && (port == SMB_PORT1 ||
                                port == SMB_PORT2 || port == NMB_PORT) ) {
                        char addr[INET6_ADDRSTRLEN];
                        print_sockaddr(addr, sizeof(addr),
                                        &sock);
                        dbgtext( "bind failed on port %d ", port);
                        dbgtext( "socket_addr = %s.\n", addr);
                        dbgtext( "Error = %s\n", strerror(errno));
                }
                close(res);
                return -1;
        }

        DEBUG( 10, ( "bind succeeded on port %d\n", port ) );
        return( res );
 }

/****************************************************************************
 Create an outgoing socket. timeout is in milliseconds.
**************************************************************************/

int open_socket_out(const struct sockaddr_storage *pss, uint16_t port,
                    int timeout)
{
        char addr[INET6_ADDRSTRLEN];
        struct sockaddr_storage sock_out = *pss;
        int res,ret;
        int connect_loop = 10;
        int increment = 10;

        /* create a socket to write to */
        res = socket(pss->ss_family, SOCK_STREAM, 0);
        if (res == -1) {
                DEBUG(0,("socket error (%s)\n", strerror(errno)));
                return -1;
        }

#if defined(HAVE_IPV6)
        if (pss->ss_family == AF_INET6) {
                struct sockaddr_in6 *psa6 = (struct sockaddr_in6 *)&sock_out;
                psa6->sin6_port = htons(port);
                if (psa6->sin6_scope_id == 0 &&
                                IN6_IS_ADDR_LINKLOCAL(&psa6->sin6_addr)) {
                        setup_linklocal_scope_id((struct sockaddr *)&sock_out);
                }
        }
#endif
        if (pss->ss_family == AF_INET) {
                struct sockaddr_in *psa = (struct sockaddr_in *)&sock_out;
                psa->sin_port = htons(port);
        }

        /* set it non-blocking */
        set_blocking(res,false);

        print_sockaddr(addr, sizeof(addr), &sock_out);
        DEBUG(3,("Connecting to %s at port %u\n",
                                addr,
                                (unsigned int)port));

        /* and connect it to the destination */
  connect_again:

        ret = sys_connect(res, (struct sockaddr *)&sock_out);

        /* Some systems return EAGAIN when they mean EINPROGRESS */
        if (ret < 0 && (errno == EINPROGRESS || errno == EALREADY ||
                        errno == EAGAIN) && (connect_loop < timeout) ) {
                smb_msleep(connect_loop);
                timeout -= connect_loop;
                connect_loop += increment;
                if (increment < 250) {
                        /* After 8 rounds we end up at a max of 255 msec */
                        increment *= 1.5;
                }
                goto connect_again;
        }

        if (ret < 0 && (errno == EINPROGRESS || errno == EALREADY ||
                        errno == EAGAIN)) {
                DEBUG(1,("timeout connecting to %s:%u\n",
                                        addr,
                                        (unsigned int)port));
                close(res);
                return -1;
        }

#ifdef EISCONN
        if (ret < 0 && errno == EISCONN) {
                errno = 0;
                ret = 0;
        }
#endif

        if (ret < 0) {
                DEBUG(2,("error connecting to %s:%d (%s)\n",
                                addr,
                                (unsigned int)port,
                                strerror(errno)));
                close(res);
                return -1;
        }

        /* set it blocking again */
        set_blocking(res,true);

        return res;
}

/*******************************************************************
 Create an outgoing TCP socket to the first addr that connects.

 This is for simultaneous connection attempts to port 445 and 139 of a host
 or for simultatneous connection attempts to multiple DCs at once.  We return
 a socket fd of the first successful connection.

 @param[in] addrs list of Internet addresses and ports to connect to
 @param[in] num_addrs number of address/port pairs in the addrs list
 @param[in] timeout time after which we stop waiting for a socket connection
            to succeed, given in milliseconds
 @param[out] fd_index the entry in addrs which we successfully connected to
 @param[out] fd fd of the open and connected socket
 @return true on a successful connection, false if all connection attempts
         failed or we timed out
*******************************************************************/

bool open_any_socket_out(struct sockaddr_storage *addrs, int num_addrs,
                         int timeout, int *fd_index, int *fd)
{
        int i, resulting_index, res;
        int *sockets;
        bool good_connect;

        fd_set r_fds, wr_fds;
        struct timeval tv;
        int maxfd;

        int connect_loop = 10000; /* 10 milliseconds */

        timeout *= 1000;        /* convert to microseconds */

        sockets = SMB_MALLOC_ARRAY(int, num_addrs);

        if (sockets == NULL)
                return false;

        resulting_index = -1;

        for (i=0; i<num_addrs; i++)
                sockets[i] = -1;

        for (i=0; i<num_addrs; i++) {
                sockets[i] = socket(addrs[i].ss_family, SOCK_STREAM, 0);
                if (sockets[i] < 0)
                        goto done;
                set_blocking(sockets[i], false);
        }

 connect_again:
        good_connect = false;

        for (i=0; i<num_addrs; i++) {
                const struct sockaddr * a = 
                    (const struct sockaddr *)&(addrs[i]);

                if (sockets[i] == -1)
                        continue;

                if (sys_connect(sockets[i], a) == 0) {
                        /* Rather unlikely as we are non-blocking, but it
                         * might actually happen. */
                        resulting_index = i;
                        goto done;
                }

                if (errno == EINPROGRESS || errno == EALREADY ||
#ifdef EISCONN
                        errno == EISCONN ||
#endif
                    errno == EAGAIN || errno == EINTR) {
                        /* These are the error messages that something is
                           progressing. */
                        good_connect = true;
                } else if (errno != 0) {
                        /* There was a direct error */
                        close(sockets[i]);
                        sockets[i] = -1;
                }
        }

        if (!good_connect) {
                /* All of the connect's resulted in real error conditions */
                goto done;
        }

        /* Lets see if any of the connect attempts succeeded */

        maxfd = 0;
        FD_ZERO(&wr_fds);
        FD_ZERO(&r_fds);

        for (i=0; i<num_addrs; i++) {
                if (sockets[i] == -1)
                        continue;
                FD_SET(sockets[i], &wr_fds);
                FD_SET(sockets[i], &r_fds);
                if (sockets[i]>maxfd)
                        maxfd = sockets[i];
        }

        tv.tv_sec = 0;
        tv.tv_usec = connect_loop;

        res = sys_select_intr(maxfd+1, &r_fds, &wr_fds, NULL, &tv);

        if (res < 0)
                goto done;

        if (res == 0)
                goto next_round;

        for (i=0; i<num_addrs; i++) {

                if (sockets[i] == -1)
                        continue;

                /* Stevens, Network Programming says that if there's a
                 * successful connect, the socket is only writable. Upon an
                 * error, it's both readable and writable. */

                if (FD_ISSET(sockets[i], &r_fds) &&
                    FD_ISSET(sockets[i], &wr_fds)) {
                        /* readable and writable, so it's an error */
                        close(sockets[i]);
                        sockets[i] = -1;
                        continue;
                }

                if (!FD_ISSET(sockets[i], &r_fds) &&
                    FD_ISSET(sockets[i], &wr_fds)) {
                        /* Only writable, so it's connected */
                        resulting_index = i;
                        goto done;
                }
        }

 next_round:

        timeout -= connect_loop;
        if (timeout <= 0)
                goto done;
        connect_loop *= 1.5;
        if (connect_loop > timeout)
                connect_loop = timeout;
        goto connect_again;

 done:
        for (i=0; i<num_addrs; i++) {
                if (i == resulting_index)
                        continue;
                if (sockets[i] >= 0)
                        close(sockets[i]);
        }

        if (resulting_index >= 0) {
                *fd_index = resulting_index;
                *fd = sockets[*fd_index];
                set_blocking(*fd, true);
        }

        free(sockets);

        return (resulting_index >= 0);
}
/****************************************************************************
 Open a connected UDP socket to host on port
**************************************************************************/

int open_udp_socket(const char *host, int port)
{
        int type = SOCK_DGRAM;
        struct sockaddr_in sock_out;
        int res;
        struct in_addr addr;

        addr = interpret_addr2(host);

        res = socket(PF_INET, type, 0);
        if (res == -1) {
                return -1;
        }

        memset((char *)&sock_out,'\0',sizeof(sock_out));
        putip((char *)&sock_out.sin_addr,(char *)&addr);
        sock_out.sin_port = htons(port);
        sock_out.sin_family = PF_INET;

        if (sys_connect(res,(struct sockaddr *)&sock_out)) {
                close(res);
                return -1;
        }

        return res;
}

/*******************************************************************
 Return the IP addr of the remote end of a socket as a string.
 Optionally return the struct sockaddr_storage.
 ******************************************************************/

static const char *get_peer_addr_internal(int fd,
                                char *addr_buf,
                                size_t addr_buf_len,
                                struct sockaddr *pss,
                                socklen_t *plength)
{
        struct sockaddr_storage ss;
        socklen_t length = sizeof(ss);

        strlcpy(addr_buf,"0.0.0.0",addr_buf_len);

        if (fd == -1) {
                return addr_buf;
        }

        if (pss == NULL) {
                pss = (struct sockaddr *)&ss;
                plength = &length;
        }

        if (getpeername(fd, (struct sockaddr *)pss, plength) < 0) {
                DEBUG(0,("getpeername failed. Error was %s\n",
                                        strerror(errno) ));
                return addr_buf;
        }

        print_sockaddr_len(addr_buf,
                        addr_buf_len,
                        pss,
                        *plength);
        return addr_buf;
}

/*******************************************************************
 Matchname - determine if host name matches IP address. Used to
 confirm a hostname lookup to prevent spoof attacks.
******************************************************************/

static bool matchname(const char *remotehost,
                const struct sockaddr *pss,
                socklen_t len)
{
        struct addrinfo *res = NULL;
        struct addrinfo *ailist = NULL;
        char addr_buf[INET6_ADDRSTRLEN];
        bool ret = interpret_string_addr_internal(&ailist,
                        remotehost,
                        AI_ADDRCONFIG|AI_CANONNAME);

        if (!ret || ailist == NULL) {
                DEBUG(3,("matchname: getaddrinfo failed for "
                        "name %s [%s]\n",
                        remotehost,
                        gai_strerror(ret) ));
                return false;
        }

        /*
         * Make sure that getaddrinfo() returns the "correct" host name.
         */

        if (ailist->ai_canonname == NULL ||
                (!strequal(remotehost, ailist->ai_canonname) &&
                 !strequal(remotehost, "localhost"))) {
                DEBUG(0,("matchname: host name/name mismatch: %s != %s\n",
                         remotehost,
                         ailist->ai_canonname ?
                                 ailist->ai_canonname : "(NULL)"));
                freeaddrinfo(ailist);
                return false;
        }

        /* Look up the host address in the address list we just got. */
        for (res = ailist; res; res = res->ai_next) {
                if (!res->ai_addr) {
                        continue;
                }
                if (sockaddr_equal((const struct sockaddr *)res->ai_addr,
                                        (struct sockaddr *)pss)) {
                        freeaddrinfo(ailist);
                        return true;
                }
        }

        /*
         * The host name does not map to the original host address. Perhaps
         * someone has compromised a name server. More likely someone botched
         * it, but that could be dangerous, too.
         */

        DEBUG(0,("matchname: host name/address mismatch: %s != %s\n",
                print_sockaddr_len(addr_buf,
                        sizeof(addr_buf),
                        pss,
                        len),
                 ailist->ai_canonname ? ailist->ai_canonname : "(NULL)"));

        if (ailist) {
                freeaddrinfo(ailist);
        }
        return false;
}

/*******************************************************************
 Deal with the singleton cache.
******************************************************************/

struct name_addr_pair {
        struct sockaddr_storage ss;
        const char *name;
};

/*******************************************************************
 Lookup a name/addr pair. Returns memory allocated from memcache.
******************************************************************/

static bool lookup_nc(struct name_addr_pair *nc)
{
        DATA_BLOB tmp;

        ZERO_STRUCTP(nc);

        if (!memcache_lookup(
                        NULL, SINGLETON_CACHE,
                        data_blob_string_const_null("get_peer_name"),
                        &tmp)) {
                return false;
        }

        memcpy(&nc->ss, tmp.data, sizeof(nc->ss));
        nc->name = (const char *)tmp.data + sizeof(nc->ss);
        return true;
}

/*******************************************************************
 Save a name/addr pair.
******************************************************************/

static void store_nc(const struct name_addr_pair *nc)
{
        DATA_BLOB tmp;
        size_t namelen = strlen(nc->name);

        tmp = data_blob(NULL, sizeof(nc->ss) + namelen + 1);
        if (!tmp.data) {
                return;
        }
        memcpy(tmp.data, &nc->ss, sizeof(nc->ss));
        memcpy(tmp.data+sizeof(nc->ss), nc->name, namelen+1);

        memcache_add(NULL, SINGLETON_CACHE,
                        data_blob_string_const_null("get_peer_name"),
                        tmp);
        data_blob_free(&tmp);
}

/*******************************************************************
 Return the DNS name of the remote end of a socket.
******************************************************************/

const char *get_peer_name(int fd, bool force_lookup)
{
        struct name_addr_pair nc;
        char addr_buf[INET6_ADDRSTRLEN];
        struct sockaddr_storage ss;
        socklen_t length = sizeof(ss);
        const char *p;
        int ret;
        char name_buf[MAX_DNS_NAME_LENGTH];
        char tmp_name[MAX_DNS_NAME_LENGTH];

        /* reverse lookups can be *very* expensive, and in many
           situations won't work because many networks don't link dhcp
           with dns. To avoid the delay we avoid the lookup if
           possible */
        if (!lp_hostname_lookups() && (force_lookup == false)) {
                length = sizeof(nc.ss);
                nc.name = get_peer_addr_internal(fd, addr_buf, sizeof(addr_buf),
                        (struct sockaddr *)&nc.ss, &length);
                store_nc(&nc);
                lookup_nc(&nc);
                return nc.name ? nc.name : "UNKNOWN";
        }

        lookup_nc(&nc);

        memset(&ss, '\0', sizeof(ss));
        p = get_peer_addr_internal(fd, addr_buf, sizeof(addr_buf), (struct sockaddr *)&ss, &length);

        /* it might be the same as the last one - save some DNS work */
        if (sockaddr_equal((struct sockaddr *)&ss, (struct sockaddr *)&nc.ss)) {
                return nc.name ? nc.name : "UNKNOWN";
        }

        /* Not the same. We need to lookup. */
        if (fd == -1) {
                return "UNKNOWN";
        }

        /* Look up the remote host name. */
        ret = sys_getnameinfo((struct sockaddr *)&ss,
                        length,
                        name_buf,
                        sizeof(name_buf),
                        NULL,
                        0,
                        0);

        if (ret) {
                DEBUG(1,("get_peer_name: getnameinfo failed "
                        "for %s with error %s\n",
                        p,
                        gai_strerror(ret)));
                strlcpy(name_buf, p, sizeof(name_buf));
        } else {
                if (!matchname(name_buf, (struct sockaddr *)&ss, length)) {
                        DEBUG(0,("Matchname failed on %s %s\n",name_buf,p));
                        strlcpy(name_buf,"UNKNOWN",sizeof(name_buf));
                }
        }

        /* can't pass the same source and dest strings in when you
           use --enable-developer or the clobber_region() call will
           get you */

        strlcpy(tmp_name, name_buf, sizeof(tmp_name));
        alpha_strcpy(name_buf, tmp_name, "_-.", sizeof(name_buf));
        if (strstr(name_buf,"..")) {
                strlcpy(name_buf, "UNKNOWN", sizeof(name_buf));
        }

        nc.name = name_buf;
        nc.ss = ss;

        store_nc(&nc);
        lookup_nc(&nc);
        return nc.name ? nc.name : "UNKNOWN";
}

/*******************************************************************
 Return the IP addr of the remote end of a socket as a string.
 ******************************************************************/

const char *get_peer_addr(int fd, char *addr, size_t addr_len)
{
        return get_peer_addr_internal(fd, addr, addr_len, NULL, NULL);
}

/*******************************************************************
 Create protected unix domain socket.

 Some unixes cannot set permissions on a ux-dom-sock, so we
 have to make sure that the directory contains the protection
 permissions instead.
 ******************************************************************/

int create_pipe_sock(const char *socket_dir,
                     const char *socket_name,
                     mode_t dir_perms)
{
#ifdef HAVE_UNIXSOCKET
        struct sockaddr_un sunaddr;
        struct stat st;
        int sock;
        mode_t old_umask;
        char *path = NULL;

        old_umask = umask(0);

        /* Create the socket directory or reuse the existing one */

        if (lstat(socket_dir, &st) == -1) {
                if (errno == ENOENT) {
                        /* Create directory */
                        if (mkdir(socket_dir, dir_perms) == -1) {
                                DEBUG(0, ("error creating socket directory "
                                        "%s: %s\n", socket_dir,
                                        strerror(errno)));
                                goto out_umask;
                        }
                } else {
                        DEBUG(0, ("lstat failed on socket directory %s: %s\n",
                                socket_dir, strerror(errno)));
                        goto out_umask;
                }
        } else {
                /* Check ownership and permission on existing directory */
                if (!S_ISDIR(st.st_mode)) {
                        DEBUG(0, ("socket directory %s isn't a directory\n",
                                socket_dir));
                        goto out_umask;
                }
                if ((st.st_uid != sec_initial_uid()) ||
                                ((st.st_mode & 0777) != dir_perms)) {
                        DEBUG(0, ("invalid permissions on socket directory "
                                "%s\n", socket_dir));
                        goto out_umask;
                }
        }

        /* Create the socket file */

        sock = socket(AF_UNIX, SOCK_STREAM, 0);

        if (sock == -1) {
                DEBUG(0, ("create_pipe_sock: socket error %s\n",
                        strerror(errno) ));
                goto out_close;
        }

        if (asprintf(&path, "%s/%s", socket_dir, socket_name) == -1) {
                goto out_close;
        }

        unlink(path);
        memset(&sunaddr, 0, sizeof(sunaddr));
        sunaddr.sun_family = AF_UNIX;
        strlcpy(sunaddr.sun_path, path, sizeof(sunaddr.sun_path));

        if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) == -1) {
                DEBUG(0, ("bind failed on pipe socket %s: %s\n", path,
                        strerror(errno)));
                goto out_close;
        }

        if (listen(sock, 5) == -1) {
                DEBUG(0, ("listen failed on pipe socket %s: %s\n", path,
                        strerror(errno)));
                goto out_close;
        }

        SAFE_FREE(path);

        umask(old_umask);
        return sock;

out_close:
        SAFE_FREE(path);
        if (sock != -1)
                close(sock);

out_umask:
        umask(old_umask);
        return -1;

#else
        DEBUG(0, ("create_pipe_sock: No Unix sockets on this system\n"));
        return -1;
#endif /* HAVE_UNIXSOCKET */
}

/****************************************************************************
 Get my own canonical name, including domain.
****************************************************************************/

const char *get_mydnsfullname(void)
{
        struct addrinfo *res = NULL;
        char my_hostname[HOST_NAME_MAX];
        bool ret;
        DATA_BLOB tmp;

        if (memcache_lookup(NULL, SINGLETON_CACHE,
                        data_blob_string_const_null("get_mydnsfullname"),
                        &tmp)) {
                SMB_ASSERT(tmp.length > 0);
                return (const char *)tmp.data;
        }

        /* get my host name */
        if (gethostname(my_hostname, sizeof(my_hostname)) == -1) {
                DEBUG(0,("get_mydnsfullname: gethostname failed\n"));
                return NULL;
        }

        /* Ensure null termination. */
        my_hostname[sizeof(my_hostname)-1] = '\0';

        ret = interpret_string_addr_internal(&res,
                                my_hostname,
                                AI_ADDRCONFIG|AI_CANONNAME);

        if (!ret || res == NULL) {
                DEBUG(3,("get_mydnsfullname: getaddrinfo failed for "
                        "name %s [%s]\n",
                        my_hostname,
                        gai_strerror(ret) ));
                return NULL;
        }

        /*
         * Make sure that getaddrinfo() returns the "correct" host name.
         */

        if (res->ai_canonname == NULL) {
                DEBUG(3,("get_mydnsfullname: failed to get "
                        "canonical name for %s\n",
                        my_hostname));
                freeaddrinfo(res);
                return NULL;
        }

        /* This copies the data, so we must do a lookup
         * afterwards to find the value to return.
         */

        memcache_add(NULL, SINGLETON_CACHE,
                        data_blob_string_const_null("get_mydnsfullname"),
                        data_blob_string_const_null(res->ai_canonname));

        if (!memcache_lookup(NULL, SINGLETON_CACHE,
                        data_blob_string_const_null("get_mydnsfullname"),
                        &tmp)) {
                tmp = data_blob_talloc(talloc_tos(), res->ai_canonname,
                                strlen(res->ai_canonname) + 1);
        }

        freeaddrinfo(res);

        return (const char *)tmp.data;
}

/************************************************************
 Is this my name ?
************************************************************/

bool is_myname_or_ipaddr(const char *s)
{
        TALLOC_CTX *ctx = talloc_tos();
        char *name = NULL;
        const char *dnsname;
        char *servername = NULL;

        if (!s) {
                return false;
        }

        /* Santize the string from '\\name' */
        name = talloc_strdup(ctx, s);
        if (!name) {
                return false;
        }

        servername = strrchr_m(name, '\\' );
        if (!servername) {
                servername = name;
        } else {
                servername++;
        }

        /* Optimize for the common case */
        if (strequal(servername, global_myname())) {
                return true;
        }

        /* Check for an alias */
        if (is_myname(servername)) {
                return true;
        }

        /* Check for loopback */
        if (strequal(servername, "127.0.0.1") ||
                        strequal(servername, "::1")) {
                return true;
        }

        if (strequal(servername, "localhost")) {
                return true;
        }

        /* Maybe it's my dns name */
        dnsname = get_mydnsfullname();
        if (dnsname && strequal(servername, dnsname)) {
                return true;
        }

        /* Handle possible CNAME records - convert to an IP addr. */
        if (!is_ipaddress(servername)) {
                /* Use DNS to resolve the name, but only the first address */
                struct sockaddr_storage ss;
                if (interpret_string_addr(&ss, servername,0)) {
                        print_sockaddr(name,
                                        sizeof(name),
                                        &ss);
                        servername = name;
                }
        }

        /* Maybe its an IP address? */
        if (is_ipaddress(servername)) {
                struct sockaddr_storage ss;
                struct iface_struct *nics;
                int i, n;

                if (!interpret_string_addr(&ss, servername, AI_NUMERICHOST)) {
                        return false;
                }

                if (is_zero_addr((struct sockaddr *)&ss) || 
                        is_loopback_addr((struct sockaddr *)&ss)) {
                        return false;
                }

                nics = TALLOC_ARRAY(ctx, struct iface_struct,
                                        MAX_INTERFACES);
                if (!nics) {
                        return false;
                }
                n = get_interfaces(nics, MAX_INTERFACES);
                for (i=0; i<n; i++) {
                        if (sockaddr_equal((struct sockaddr *)&nics[i].ip, (struct sockaddr *)&ss)) {
                                TALLOC_FREE(nics);
                                return true;
                        }
                }
                TALLOC_FREE(nics);
        }

        /* No match */
        return false;
}