]> git.meshlink.io Git - meshlink/blob - src/meta.c
Move assert()s that dereference a pointer to after the pointer NULL check.
[meshlink] / src / meta.c
1 /*
2     meta.c -- handle the meta communication
3     Copyright (C) 2014-2017 Guus Sliepen <guus@meshlink.io>,
4
5     This program is free software; you can redistribute it and/or modify
6     it under the terms of the GNU General Public License as published by
7     the Free Software Foundation; either version 2 of the License, or
8     (at your option) any later version.
9
10     This program is distributed in the hope that it will be useful,
11     but WITHOUT ANY WARRANTY; without even the implied warranty of
12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13     GNU General Public License for more details.
14
15     You should have received a copy of the GNU General Public License along
16     with this program; if not, write to the Free Software Foundation, Inc.,
17     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19
20 #include "system.h"
21
22 #include "connection.h"
23 #include "logger.h"
24 #include "meshlink_internal.h"
25 #include "meta.h"
26 #include "net.h"
27 #include "protocol.h"
28 #include "utils.h"
29 #include "xalloc.h"
30
31 bool send_meta_sptps(void *handle, uint8_t type, const void *buffer, size_t length) {
32         (void)type;
33
34         assert(handle);
35         assert(buffer);
36         assert(length);
37
38         connection_t *c = handle;
39         meshlink_handle_t *mesh = c->mesh;
40
41         buffer_add(&c->outbuf, (const char *)buffer, length);
42         io_set(&mesh->loop, &c->io, IO_READ | IO_WRITE);
43
44         return true;
45 }
46
47 bool send_meta(meshlink_handle_t *mesh, connection_t *c, const char *buffer, int length) {
48         assert(c);
49         assert(buffer);
50         assert(length);
51
52         logger(mesh, MESHLINK_DEBUG, "Sending %d bytes of metadata to %s", length, c->name);
53
54         if(c->allow_request == ID) {
55                 buffer_add(&c->outbuf, buffer, length);
56                 io_set(&mesh->loop, &c->io, IO_READ | IO_WRITE);
57                 return true;
58         }
59
60         return sptps_send_record(&c->sptps, 0, buffer, length);
61 }
62
63 void broadcast_meta(meshlink_handle_t *mesh, connection_t *from, const char *buffer, int length) {
64         assert(buffer);
65         assert(length);
66
67         for list_each(connection_t, c, mesh->connections)
68                 if(c != from && c->status.active) {
69                         send_meta(mesh, c, buffer, length);
70                 }
71 }
72
73 void broadcast_submesh_meta(meshlink_handle_t *mesh, connection_t *from, submesh_t *s, const char *buffer, int length) {
74         assert(buffer);
75         assert(length);
76
77         for list_each(connection_t, c, mesh->connections)
78                 if(c != from && c->status.active) {
79                         if(c->node && submesh_allows_node(s, c->node)) {
80                                 send_meta(mesh, c, buffer, length);
81                         }
82                 }
83 }
84
85 bool receive_meta_sptps(void *handle, uint8_t type, const void *data, uint16_t length) {
86         assert(handle);
87         assert(!length || data);
88
89         connection_t *c = handle;
90         meshlink_handle_t *mesh = c->mesh;
91         char *request = (char *)data;
92
93         if(!c) {
94                 logger(mesh, MESHLINK_ERROR, "receive_meta_sptps() called with NULL pointer!");
95                 abort();
96         }
97
98         if(type == SPTPS_HANDSHAKE) {
99                 if(c->allow_request == ACK) {
100                         return send_ack(mesh, c);
101                 } else {
102                         return true;
103                 }
104         }
105
106         if(!request) {
107                 return true;
108         }
109
110         /* Are we receiving a TCPpacket? */
111
112         if(c->tcplen) {
113                 abort(); // TODO: get rid of tcplen altogether
114         }
115
116         /* Change newline to null byte, just like non-SPTPS requests */
117
118         if(request[length - 1] == '\n') {
119                 request[length - 1] = 0;
120         }
121
122         /* Otherwise we are waiting for a request */
123
124         return receive_request(mesh, c, request);
125 }
126
127 bool receive_meta(meshlink_handle_t *mesh, connection_t *c) {
128         int inlen;
129         char inbuf[MAXBUFSIZE];
130
131         inlen = recv(c->socket, inbuf, sizeof(inbuf), 0);
132
133         if(inlen <= 0) {
134                 if(!inlen || !errno) {
135                         logger(mesh, MESHLINK_INFO, "Connection closed by %s", c->name);
136                 } else if(sockwouldblock(sockerrno)) {
137                         return true;
138                 } else {
139                         logger(mesh, MESHLINK_ERROR, "Metadata socket read error for %s: %s", c->name, sockstrerror(sockerrno));
140                 }
141
142                 return false;
143         }
144
145         if(c->allow_request == ID) {
146                 buffer_add(&c->inbuf, inbuf, inlen);
147
148                 char *request = buffer_readline(&c->inbuf);
149
150                 if(request) {
151                         if(!receive_request(mesh, c, request) || c->allow_request == ID) {
152                                 return false;
153                         }
154
155                         int left = c->inbuf.len - c->inbuf.offset;
156
157                         if(left > 0) {
158                                 return sptps_receive_data(&c->sptps, buffer_read(&c->inbuf, left), left);
159                         } else {
160                                 return true;
161                         }
162                 }
163
164                 if(c->inbuf.len >= sizeof(inbuf)) {
165                         logger(mesh, MESHLINK_ERROR, "Input buffer full for %s", c->name);
166                         return false;
167                 } else {
168                         return true;
169                 }
170         }
171
172         return sptps_receive_data(&c->sptps, inbuf, inlen);
173 }