1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
|
#include "client.h"
#include "proxy.h"
#include "epoll.h"
#include "helper.h"
#include "asn1.h"
#include "openssl.h"
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
static void client_haveIn(epoll_client_t *client);
static BOOL client_haveOut(epoll_client_t *client);
void client_free(epoll_client_t *client)
{
proxy_removeClient(client);
if (client->sendBuffer != NULL) free(client->sendBuffer);
if (client->ssl != NULL) SSL_free(client->ssl);
if (client->fd != -1) {
//ePoll_remove(client->fd); // epoll would remove closed descriptors automatically, but just to be sure we don't cause use after free, we remove it explicitly
close(client->fd);
}
free(client);
}
void client_callback(void *data, int haveIn, int haveOut, int doCleanup)
{
epoll_client_t *client = (epoll_client_t*)data;
if (doCleanup || client->kill) {
//printf("Client gone (1).\n");
client_free(client);
return;
}
if (client->ssl == NULL) {
// Plain connection
if (haveIn) client_haveIn(client);
if (haveOut || client->kill) {
if (client_haveOut(client)) return;
}
if (client->kill) {
//printf("Client gone (2).\n");
client_free(client);
}
return;
}
// SSL connection
if (!client->sslAccepted) {
// Still SSL-Connecting
if (!ssl_acceptClient(client)) {
printf("[Proxy] SSL Client accept failed.\n");
client_free(client);
return;
}
if (!client->sslAccepted) return;
}
// Since we don't know if the incoming data is just wrapped application data or ssl protocol stuff, we always call both
client_haveIn(client);
if (client_haveOut(client)) return;
if (client->kill) {
//printf("Client gone (3).\n");
client_free(client);
}
}
static void client_haveIn(epoll_client_t *client)
{
for (;;) {
if (client->rbPos >= REQLEN) {
printf("[Proxy] Buffer overflow reading from client. Disconnecting.\n");
client->kill = TRUE;
return;
}
const size_t buflen = REQLEN - client->rbPos;
ssize_t ret;
if (client->ssl == NULL) {
// Plain
ret = read(client->fd, client->readBuffer + client->rbPos, buflen);
if (ret < 0 && errno == EINTR) continue;
if (ret < 0 && errno == EAGAIN) break;
if (ret <= 0) {
if (client->kill) return;
printf("[Proxy] Client gone while reading (ret=%d, errno=%d).\n", (int)ret, errno);
client->kill = TRUE;
return;
}
} else {
// SSL
ret = SSL_read(client->ssl, client->readBuffer + client->rbPos, buflen);
if (ret <= 0) {
if (client->kill) return;
int err = SSL_get_error(client->ssl, ret);
if (SSL_BLOCKED(err)) break;
if (err == SSL_ERROR_ZERO_RETURN) {
SSL_shutdown(client->ssl);
// Might have to handle error return codes; need another state in epoll_client_t for this
}
printf("[Proxy] SSL client gone while reading (ret=%d, err=%d).\n", (int)ret, err);
client->kill = TRUE;
return;
}
}
// We reach here if something was read (so ret > 0)
client->rbPos += ret;
// Request complete?
for (;;) {
size_t consumed, len;
consumed = scan_asn1SEQUENCE(client->readBuffer, client->readBuffer + client->rbPos, &len);
if (consumed == 0) break; // Length-Header not complete
len += consumed;
if (len > client->rbPos) break; // Body not complete yet
if (!proxy_fromClient(client, len)) {
printf("[Proxy] Error parsing request from client.\n");
client->kill = TRUE;
return;
}
// Shift remaining buffer contents
if (len == client->rbPos) {
client->rbPos = 0;
break;
}
memmove(client->readBuffer, client->readBuffer + len, client->rbPos - len);
client->rbPos -= len;
}
if (client->ssl == NULL && (ssize_t)buflen > ret) break; // Read less than buffer len, epoll will fire again
}
}
/**
* Send any queued data.
* Returns TRUE if anything has been sent, or the socket
* buffer is currently full (EAGAIN, non-blocking mode)
*/
static BOOL client_haveOut(epoll_client_t *client)
{
client->writeBlocked = FALSE;
if (client->sbPos >= client->sbFill) return FALSE;
while (client->sbPos < client->sbFill) {
const int tosend = client->sbFill - client->sbPos;
ssize_t ret;
if (client->ssl == NULL) {
// Plain
ret = write(client->fd, client->sendBuffer + client->sbPos, tosend);
if (ret < 0 && errno == EINTR) continue;
if (ret < 0 && errno == EAGAIN) return TRUE;
if (ret <= 0) {
printf("[Proxy] Cannot send to client (ret=%d, errno=%d)\n", (int)ret, errno);
client->kill = TRUE;
return FALSE;
}
} else {
// SSL
ret = SSL_write(client->ssl, client->sendBuffer + client->sbPos, tosend);
if (ret <= 0) {
int err = SSL_get_error(client->ssl, ret);
if (SSL_BLOCKED(err)) {
client->writeBlocked = TRUE;
return TRUE; // Blocking
}
printf("[Proxy] SSL cannot send to client (ret=%d, err=%d)\n", (int)ret, err);
ERR_print_errors_fp(stdout);
client->kill = TRUE;
return FALSE; // Closed
}
}
client->sbPos += ret;
if (client->ssl != NULL) {
memmove(client->sendBuffer, client->sendBuffer + client->sbPos, client->sbFill - client->sbPos);
client->sbFill -= client->sbPos;
client->sbPos = 0;
}
if (client->ssl == NULL && ret != tosend) return TRUE; // Sent less than requested -> buffer full, epoll will trigger us again
}
client->sbPos = client->sbFill = 0;
if (client->ssl == NULL && client->sbLen > MAXMSGLEN / 2) {
helper_realloc(&client->sendBuffer, &client->sbLen, 8000, "client_haveOut");
}
return TRUE;
}
BOOL client_send(epoll_client_t *client, const char *buffer, size_t len, const BOOL cork)
{
if (client->ssl == NULL && client->sbFill == 0 && !cork) {
// Nothing in send buffer, fire away
const int ret = write(client->fd, buffer, len);
if (ret == 0 || (ret < 0 && errno != EINTR && errno != EAGAIN)) {
printf("[Proxy] Client gone when trying to send.\n");
client->kill = TRUE;
return FALSE;
}
if (ret == (int)len) return TRUE;
// Couldn't send everything, continue with buffering logic below
if (ret > 0) {
buffer += ret;
len -= (size_t)ret;
}
}
// Buffer...
if (client->sbLen - client->sbFill < len) { // Buffer too small?
if (client->writeBlocked) {
printf("[Proxy] SSL write to client blocked and buffer to small (%d bytes)\n", (int)client->sbLen);
client->kill = TRUE;
return FALSE;
}
if (client->sbPos != 0) { // See if we can compact it
memmove(client->sendBuffer, client->sendBuffer + client->sbPos, client->sbFill - client->sbPos);
client->sbFill -= client->sbPos;
client->sbPos = 0;
}
// Sanity
if (client->sbFill + len > MAXMSGLEN) {
printf("[Proxy] Dropping client as the send buffer would exceed %d bytes.\n", (int)MAXMSGLEN);
client->kill = TRUE;
return FALSE;
}
if (client->sbLen - client->sbFill < len) { // Still too small after compacting? realloc
if (helper_realloc(&client->sendBuffer, &client->sbLen, client->sbLen + len + (client->ssl && client->sbLen > 0 ? MAXMSGLEN : 4000), "client_send") == -1) {
client->kill = TRUE;
return FALSE;
}
}
}
// Finally append to buffer
memcpy(client->sendBuffer + client->sbFill, buffer, len);
client->sbFill += len;
if (!cork) client_haveOut(client);
return TRUE;
}
BOOL client_searchResultError(epoll_client_t *client, const unsigned long messageId, const int code, const char *message)
{
const size_t doneLen = fmt_ldapsearchresultdone(NULL, code, "", message, "");
const size_t doneHeaderLen = fmt_ldapmessage(NULL, messageId, SearchResultDone, doneLen);
char buffer[doneLen + doneHeaderLen];
fmt_ldapsearchresultdone(buffer + doneHeaderLen, code, "", message, "");
fmt_ldapmessage(buffer, messageId, SearchResultDone, doneLen);
return client_send(client, buffer, doneHeaderLen + doneLen, FALSE);
}
|
