usr/src/stand/lib/inet/udp.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 1991-2003 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * udp.c, Code implementing the UDP internet protocol.
  27  */
  28
  29 #pragma ident   "%Z%%M% %I%     %E% SMI"
  30
  31 #include <sys/types.h>
  32 #include <socket_impl.h>
  33 #include <socket_inet.h>
  34 #include <sys/salib.h>
  35 #include <sys/socket.h>
  36 #include <netinet/in_systm.h>
  37 #include <netinet/in.h>
  38 #include <netinet/ip.h>
  39 #include <netinet/udp.h>
  40
  41 #include "udp_inet.h"
  42 #include "ipv4.h"
  43 #include "ipv4_impl.h"
  44 #include "mac.h"
  45 #include "mac_impl.h"
  46 #include "v4_sum_impl.h"
  47 #include <sys/bootdebug.h>
  48
  49 /* Checksum all architectures */
  50 static int udp_cksum_flag = TRUE;       /* checksum on if set */
  51
  52 /*
  53  * Initialize the udp-specific parts of a socket.
  54  */
  55 void
  56 udp_socket_init(struct inetboot_socket *isp)
  57 {
  58         isp->type = INETBOOT_DGRAM;
  59         isp->proto = IPPROTO_UDP;
  60         isp->input[TRANSPORT_LVL] = udp_input;
  61         isp->output[TRANSPORT_LVL] = udp_output;
  62         isp->close[TRANSPORT_LVL] = NULL;
  63         isp->headerlen[TRANSPORT_LVL] = udp_header_len;
  64         isp->ports = udp_ports;
  65 }
  66
  67 /*
  68  * Return the size of an UDP header
  69  */
  70 /* ARGSUSED */
  71 int
  72 udp_header_len(struct inetgram *igm)
  73 {
  74         return (sizeof (struct udphdr));
  75 }
  76
  77 /*
  78  * Return the requested port number in network order.
  79  */
  80 in_port_t
  81 udp_ports(uint16_t *udphp, enum Ports request)
  82 {
  83         if (request == SOURCE)
  84                 return (((struct udphdr *)udphp)->uh_sport);
  85         return (((struct udphdr *)udphp)->uh_dport);
  86 }
  87
  88 /*
  89  * Process the IPv4 datagram that IPv4 has given us. We:
  90  *
  91  *      1) Checksum the datagram if checksum is turned on.
  92  *      2) Strip the udp header from the inetgram.
  93  *      3) Return the number of TRANSPORT frames for success, -1 if a
  94  *              failure occurred.
  95  *
  96  * Arguments: index: index into the open socket table, ip is the inetgram
  97  * we got from IPv4, which will contain the udp header and all the data.
  98  */
  99 int
 100 udp_input(int index)
 101 {
 102         int frames = 0, header_len;
 103         struct inetgram *igp, *ugp = NULL;
 104         struct udphdr   *udphp;
 105         mblk_t *mp;
 106
 107 #ifdef DEBUG
 108         printf("udp_input(%d) ###############################\n", index);
 109 #endif
 110         while ((igp = sockets[index].inq) != NULL) {
 111                 if (igp->igm_level != TRANSPORT_LVL) {
 112 #ifdef  DEBUG
 113                         printf("udp_input(%d): level %d datagram discarded.\n",
 114                             index, igp->igm_level);
 115 #endif  /* DEBUG */
 116                         del_gram(&sockets[index].inq, igp, TRUE);
 117                         continue;
 118                 }
 119                 mp = igp->igm_mp;
 120                 udphp = (struct udphdr *)(mp->b_rptr +
 121                     IPH_HDR_LENGTH(mp->b_rptr));
 122                 header_len = (sockets[index].headerlen[TRANSPORT_LVL])(NULL);
 123                 mp->b_rptr = ((unsigned char *)udphp) + header_len;
 124                 mp->b_wptr = ((unsigned char *)udphp) + ntohs(udphp->uh_ulen);
 125
 126                 /* generate checksum */
 127                 if (udp_cksum_flag && udphp->uh_sum != 0) {
 128                         if (udp_chksum(udphp, &igp->igm_saddr.sin_addr,
 129                             &igp->igm_target, sockets[index].proto) != 0) {
 130                                 dprintf("udp_input(%d): bad udp chksum "
 131                                     "from %s.\n", index,
 132                                     inet_ntoa(igp->igm_saddr.sin_addr));
 133                                 del_gram(&sockets[index].inq, igp, TRUE);
 134                                 continue;
 135                         }
 136                 }
 137
 138                 /* validate port number */
 139                 if (sockets[index].bind.sin_port != udphp->uh_dport) {
 140                         dprintf("udp_input(%d): Unexpected port number: "
 141                             "%d != %d from %s.\n", index,
 142                             ntohs(udphp->uh_dport), ntohs(
 143                             sockets[index].bind.sin_port),
 144                             inet_ntoa(igp->igm_saddr.sin_addr));
 145                         del_gram(&sockets[index].inq, igp, TRUE);
 146                         continue;
 147                 }
 148
 149                 igp->igm_level = APP_LVL;
 150                 del_gram(&sockets[index].inq, igp, FALSE);
 151                 add_grams(&ugp, igp);
 152                 frames++;
 153         }
 154         add_grams(&sockets[index].inq, ugp);
 155
 156         return (frames);
 157 }
 158
 159 /*
 160  * Create a UDP datagram given the data and sockaddr_in we got from sendto().
 161  * We will calculate the checksum if checksumming is turned on, and fill in
 162  * appropriate length and port fields. We convert the inetgram from a
 163  * block of data into a udp datagram... Returns the number of bytes contained
 164  * in the udp datagram (including header).
 165  *
 166  * Arguments: index: index into the open socket table, ogp is the inetgram
 167  * we got from sendto(), which will contain just the data and sockaddr_in.
 168  */
 169 int
 170 udp_output(int index, struct inetgram *ogp)
 171 {
 172         struct udphdr   *udphp;
 173         mblk_t          *mp;
 174
 175 #ifdef  DEBUG
 176         printf("udp_output(%d): 0x%x, %d\n", index, ogp->igm_mp,
 177             ogp->igm_mp->b_wptr - ogp->igm_mp->b_rptr);
 178 #endif  /* DEBUG */
 179
 180         mp = ogp->igm_mp;
 181         mp->b_rptr -= sizeof (struct udphdr);
 182         udphp = (struct udphdr *)(mp->b_rptr);
 183
 184         udphp->uh_dport = ogp->igm_saddr.sin_port;
 185         if (sockets[index].bound)
 186                 udphp->uh_sport = sockets[index].bind.sin_port;
 187         else
 188                 udphp->uh_sport = ogp->igm_saddr.sin_port;
 189         udphp->uh_ulen = htons(mp->b_wptr - mp->b_rptr);
 190         udphp->uh_sum = 0;
 191
 192         if (udp_cksum_flag) {
 193                 udphp->uh_sum = udp_chksum(udphp, &sockets[index].bind.sin_addr,
 194                     &ogp->igm_saddr.sin_addr, sockets[index].proto);
 195         }
 196
 197         ogp->igm_level = NETWORK_LVL;
 198
 199         return (0);
 200 }