-
Notifications
You must be signed in to change notification settings - Fork 0
/
client.cpp
188 lines (165 loc) · 4.61 KB
/
client.cpp
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
#include "client.h"
#include <arpa/inet.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "beacon.h"
#include "event.h"
#include "openflow.h"
#define CLIENT_STATE_WAITING_HEADER 1
#define CLIENT_STATE_WAITING_PACKET 2
#define READ_PARTIAL 1
#define READ_COMPLETE 2
#define READ_EOF 3
#define READ_STOP 4
Write::Write(uint8_t *d, uint16_t s) {
data = d;
pos = 0;
size = s;
}
Client::Client(int f, void *s) {
fd = f;
server = s;
uid = 0;
canwrite = 0;
state = CLIENT_STATE_WAITING_HEADER;
bufsize = sizeof(ofp_header_t);
pos = 0;
has_mst = 0;
cur_packet = (ofp_header_t *)malloc(bufsize);
if (cur_packet == nullptr) {
perror("malloc");
exit(-1);
}
}
void Client::init() {
init_connection(this);
}
/* Note: client will now own buf, so don't use buf after making this call */
void Client::write_packet(void *buf, uint16_t count) {
write_queue.push(Write((uint8_t *)buf, count));
flush_write_queue();
}
/* Read some data into the buffer, and handle */
void Client::handle_read_event() {
int status;
for (;;) {
status = read_into_buffer();
if (status == READ_STOP) {
break;
} else if (status == READ_EOF) {
close_client();
break;
} else if (status == READ_COMPLETE) {
switch (state) {
case CLIENT_STATE_WAITING_HEADER:
handle_header();
break;
case CLIENT_STATE_WAITING_PACKET:
handle_packet();
break;
default:
fprintf(stderr, "Unexpected client state: %d\n", state);
exit(-1);
}
}
}
}
void Client::flush_write_queue() {
ssize_t status;
while (canwrite && !write_queue.empty()) {
Write w = write_queue.front();
status = write(fd, w.data + w.pos, w.size - w.pos);
if (status < 0) {
if (errno == EAGAIN || errno == EWOULDBLOCK) {
canwrite = 0;
} else {
// fprintf(stderr, "write(%d): %s\n", fd, strerror(errno));
close_client();
break;
}
} else {
w.pos += status;
if (w.pos == w.size) {
// Complete write. Dequeue
free(w.data);
write_queue.pop();
}
}
}
}
void Client::handle_header() {
cur_packet->length = ntohs(cur_packet->length);
if (cur_packet->length > sizeof(ofp_header_t)) {
bufsize = cur_packet->length;
cur_packet = (ofp_header_t *)realloc(cur_packet, bufsize);
if (cur_packet == nullptr) {
perror("realloc");
exit(-1);
}
} else if (cur_packet->length < sizeof(ofp_header_t)) {
cur_packet->length = sizeof(ofp_header_t);
}
state = CLIENT_STATE_WAITING_PACKET;
/* Do not increment pos, we want to start reading just past the header */
}
void Client::handle_packet() {
handle_ofp_packet(this);
state = CLIENT_STATE_WAITING_HEADER;
free(cur_packet);
bufsize = sizeof(ofp_header_t);
pos = 0;
cur_packet = (ofp_header_t *)(malloc(bufsize));
if (cur_packet == nullptr) {
perror("malloc");
exit(-1);
}
}
/* Read from the client into the client's buffer.
*
* Return READ_COMPLETE if the buffer is now full
* Return READ_PARTIAL if read was successful, but the buffer is not full
* Return READ_STOP if we encountered an EAGAIN
*/
int Client::read_into_buffer() {
ssize_t status;
if (pos == bufsize) {
/* If there is nothing to read, do nothing */
return READ_COMPLETE;
}
status = read(fd, (uint8_t *)cur_packet + pos, bufsize - pos);
if (status < 0) {
/* We should never continue past this if statement */
if (errno == EAGAIN || errno == EWOULDBLOCK) {
/* Do nothing */
return READ_STOP;
} else {
perror("read");
return READ_STOP;
}
} else if (status == 0) {
/* EOF */
return READ_EOF;
}
pos += status;
return (pos == bufsize) ? READ_COMPLETE : READ_PARTIAL;
}
void Client::close_client() {
free(cur_packet);
cur_packet = nullptr;
/* Free any queued writes */
while (!write_queue.empty()) {
free(write_queue.front().data);
write_queue.pop();
}
if (close(fd) < 0) {
perror("close");
}
Server *s = (Server *)server;
s->clients.erase(fd);
if (uid) {
client_table.erase(uid);
}
}