external/bsd/bind/dist/lib/dns/tcpmsg.c

   1 /*      $NetBSD: tcpmsg.c,v 1.4 2014/12/10 04:37:58 christos Exp $      */
   2
   3 /*
   4  * Copyright (C) 2004-2007  Internet Systems Consortium, Inc. ("ISC")
   5  * Copyright (C) 1999-2001  Internet Software Consortium.
   6  *
   7  * Permission to use, copy, modify, and/or distribute this software for any
   8  * purpose with or without fee is hereby granted, provided that the above
   9  * copyright notice and this permission notice appear in all copies.
  10  *
  11  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
  12  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  13  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  14  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  15  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  16  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  17  * PERFORMANCE OF THIS SOFTWARE.
  18  */
  19
  20 /* Id: tcpmsg.c,v 1.31 2007/06/19 23:47:16 tbox Exp  */
  21
  22 /*! \file */
  23
  24 #include <config.h>
  25
  26 #include <isc/mem.h>
  27 #include <isc/task.h>
  28 #include <isc/util.h>
  29
  30 #include <dns/events.h>
  31 #include <dns/result.h>
  32 #include <dns/tcpmsg.h>
  33
  34 #ifdef TCPMSG_DEBUG
  35 #include <stdio.h>              /* Required for printf. */
  36 #define XDEBUG(x) printf x
  37 #else
  38 #define XDEBUG(x)
  39 #endif
  40
  41 #define TCPMSG_MAGIC            ISC_MAGIC('T', 'C', 'P', 'm')
  42 #define VALID_TCPMSG(foo)       ISC_MAGIC_VALID(foo, TCPMSG_MAGIC)
  43
  44 static void recv_length(isc_task_t *, isc_event_t *);
  45 static void recv_message(isc_task_t *, isc_event_t *);
  46
  47
  48 static void
  49 recv_length(isc_task_t *task, isc_event_t *ev_in) {
  50         isc_socketevent_t *ev = (isc_socketevent_t *)ev_in;
  51         isc_event_t *dev;
  52         dns_tcpmsg_t *tcpmsg = ev_in->ev_arg;
  53         isc_region_t region;
  54         isc_result_t result;
  55
  56         INSIST(VALID_TCPMSG(tcpmsg));
  57
  58         dev = &tcpmsg->event;
  59         tcpmsg->address = ev->address;
  60
  61         if (ev->result != ISC_R_SUCCESS) {
  62                 tcpmsg->result = ev->result;
  63                 goto send_and_free;
  64         }
  65
  66         /*
  67          * Success.
  68          */
  69         tcpmsg->size = ntohs(tcpmsg->size);
  70         if (tcpmsg->size == 0) {
  71                 tcpmsg->result = ISC_R_UNEXPECTEDEND;
  72                 goto send_and_free;
  73         }
  74         if (tcpmsg->size > tcpmsg->maxsize) {
  75                 tcpmsg->result = ISC_R_RANGE;
  76                 goto send_and_free;
  77         }
  78
  79         region.base = isc_mem_get(tcpmsg->mctx, tcpmsg->size);
  80         region.length = tcpmsg->size;
  81         if (region.base == NULL) {
  82                 tcpmsg->result = ISC_R_NOMEMORY;
  83                 goto send_and_free;
  84         }
  85         XDEBUG(("Allocated %d bytes\n", tcpmsg->size));
  86
  87         isc_buffer_init(&tcpmsg->buffer, region.base, region.length);
  88         result = isc_socket_recv(tcpmsg->sock, &region, 0,
  89                                  task, recv_message, tcpmsg);
  90         if (result != ISC_R_SUCCESS) {
  91                 tcpmsg->result = result;
  92                 goto send_and_free;
  93         }
  94
  95         isc_event_free(&ev_in);
  96         return;
  97
  98  send_and_free:
  99         isc_task_send(tcpmsg->task, &dev);
 100         tcpmsg->task = NULL;
 101         isc_event_free(&ev_in);
 102         return;
 103 }
 104
 105 static void
 106 recv_message(isc_task_t *task, isc_event_t *ev_in) {
 107         isc_socketevent_t *ev = (isc_socketevent_t *)ev_in;
 108         isc_event_t *dev;
 109         dns_tcpmsg_t *tcpmsg = ev_in->ev_arg;
 110
 111         (void)task;
 112
 113         INSIST(VALID_TCPMSG(tcpmsg));
 114
 115         dev = &tcpmsg->event;
 116         tcpmsg->address = ev->address;
 117
 118         if (ev->result != ISC_R_SUCCESS) {
 119                 tcpmsg->result = ev->result;
 120                 goto send_and_free;
 121         }
 122
 123         tcpmsg->result = ISC_R_SUCCESS;
 124         isc_buffer_add(&tcpmsg->buffer, ev->n);
 125
 126         XDEBUG(("Received %d bytes (of %d)\n", ev->n, tcpmsg->size));
 127
 128  send_and_free:
 129         isc_task_send(tcpmsg->task, &dev);
 130         tcpmsg->task = NULL;
 131         isc_event_free(&ev_in);
 132 }
 133
 134 void
 135 dns_tcpmsg_init(isc_mem_t *mctx, isc_socket_t *sock, dns_tcpmsg_t *tcpmsg) {
 136         REQUIRE(mctx != NULL);
 137         REQUIRE(sock != NULL);
 138         REQUIRE(tcpmsg != NULL);
 139
 140         tcpmsg->magic = TCPMSG_MAGIC;
 141         tcpmsg->size = 0;
 142         tcpmsg->buffer.base = NULL;
 143         tcpmsg->buffer.length = 0;
 144         tcpmsg->maxsize = 65535;                /* Largest message possible. */
 145         tcpmsg->mctx = mctx;
 146         tcpmsg->sock = sock;
 147         tcpmsg->task = NULL;                    /* None yet. */
 148         tcpmsg->result = ISC_R_UNEXPECTED;      /* None yet. */
 149         /*
 150          * Should probably initialize the event here, but it can wait.
 151          */
 152 }
 153
 154
 155 void
 156 dns_tcpmsg_setmaxsize(dns_tcpmsg_t *tcpmsg, unsigned int maxsize) {
 157         REQUIRE(VALID_TCPMSG(tcpmsg));
 158         REQUIRE(maxsize < 65536);
 159
 160         tcpmsg->maxsize = maxsize;
 161 }
 162
 163
 164 isc_result_t
 165 dns_tcpmsg_readmessage(dns_tcpmsg_t *tcpmsg,
 166                        isc_task_t *task, isc_taskaction_t action, void *arg)
 167 {
 168         isc_result_t result;
 169         isc_region_t region;
 170
 171         REQUIRE(VALID_TCPMSG(tcpmsg));
 172         REQUIRE(task != NULL);
 173         REQUIRE(tcpmsg->task == NULL);  /* not currently in use */
 174
 175         if (tcpmsg->buffer.base != NULL) {
 176                 isc_mem_put(tcpmsg->mctx, tcpmsg->buffer.base,
 177                             tcpmsg->buffer.length);
 178                 tcpmsg->buffer.base = NULL;
 179                 tcpmsg->buffer.length = 0;
 180         }
 181
 182         tcpmsg->task = task;
 183         tcpmsg->action = action;
 184         tcpmsg->arg = arg;
 185         tcpmsg->result = ISC_R_UNEXPECTED;  /* unknown right now */
 186
 187         ISC_EVENT_INIT(&tcpmsg->event, sizeof(isc_event_t), 0, 0,
 188                        DNS_EVENT_TCPMSG, action, arg, tcpmsg,
 189                        NULL, NULL);
 190
 191         region.base = (unsigned char *)&tcpmsg->size;
 192         region.length = 2;  /* isc_uint16_t */
 193         result = isc_socket_recv(tcpmsg->sock, &region, 0,
 194                                  tcpmsg->task, recv_length, tcpmsg);
 195
 196         if (result != ISC_R_SUCCESS)
 197                 tcpmsg->task = NULL;
 198
 199         return (result);
 200 }
 201
 202 void
 203 dns_tcpmsg_cancelread(dns_tcpmsg_t *tcpmsg) {
 204         REQUIRE(VALID_TCPMSG(tcpmsg));
 205
 206         isc_socket_cancel(tcpmsg->sock, NULL, ISC_SOCKCANCEL_RECV);
 207 }
 208
 209 void
 210 dns_tcpmsg_keepbuffer(dns_tcpmsg_t *tcpmsg, isc_buffer_t *buffer) {
 211         REQUIRE(VALID_TCPMSG(tcpmsg));
 212         REQUIRE(buffer != NULL);
 213
 214         *buffer = tcpmsg->buffer;
 215         tcpmsg->buffer.base = NULL;
 216         tcpmsg->buffer.length = 0;
 217 }
 218
 219 #if 0
 220 void
 221 dns_tcpmsg_freebuffer(dns_tcpmsg_t *tcpmsg) {
 222         REQUIRE(VALID_TCPMSG(tcpmsg));
 223
 224         if (tcpmsg->buffer.base == NULL)
 225                 return;
 226
 227         isc_mem_put(tcpmsg->mctx, tcpmsg->buffer.base, tcpmsg->buffer.length);
 228         tcpmsg->buffer.base = NULL;
 229         tcpmsg->buffer.length = 0;
 230 }
 231 #endif
 232
 233 void
 234 dns_tcpmsg_invalidate(dns_tcpmsg_t *tcpmsg) {
 235         REQUIRE(VALID_TCPMSG(tcpmsg));
 236
 237         tcpmsg->magic = 0;
 238
 239         if (tcpmsg->buffer.base != NULL) {
 240                 isc_mem_put(tcpmsg->mctx, tcpmsg->buffer.base,
 241                             tcpmsg->buffer.length);
 242                 tcpmsg->buffer.base = NULL;
 243                 tcpmsg->buffer.length = 0;
 244         }
 245 }