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
recv_length(isc_task_t * task,isc_event_t * ev_in)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, ®ion, 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
recv_message(isc_task_t * task,isc_event_t * ev_in)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
dns_tcpmsg_init(isc_mem_t * mctx,isc_socket_t * sock,dns_tcpmsg_t * tcpmsg)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
dns_tcpmsg_setmaxsize(dns_tcpmsg_t * tcpmsg,unsigned int maxsize)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
dns_tcpmsg_readmessage(dns_tcpmsg_t * tcpmsg,isc_task_t * task,isc_taskaction_t action,void * arg)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, ®ion, 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
dns_tcpmsg_cancelread(dns_tcpmsg_t * tcpmsg)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
dns_tcpmsg_keepbuffer(dns_tcpmsg_t * tcpmsg,isc_buffer_t * buffer)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
dns_tcpmsg_invalidate(dns_tcpmsg_t * tcpmsg)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 }
246