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
|
/*
* (C) 2006-2012 by Pablo Neira Ayuso <pablo@netfilter.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Part of this code has been sponsored by Vyatta Inc. <http://www.vyatta.com>
*/
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <signal.h>
#include "conntrackd.h"
#include "date.h"
#include "fds.h"
struct fds *create_fds(void)
{
struct fds *fds;
fds = (struct fds *) calloc(sizeof(struct fds), 1);
if (fds == NULL)
return NULL;
INIT_LIST_HEAD(&fds->list);
return fds;
}
void destroy_fds(struct fds *fds)
{
struct fds_item *this, *tmp;
list_for_each_entry_safe(this, tmp, &fds->list, head) {
list_del(&this->head);
FD_CLR(this->fd, &fds->readfds);
free(this);
}
free(fds);
}
int register_fd(int fd, void (*cb)(void *data), void *data, struct fds *fds)
{
struct fds_item *item;
FD_SET(fd, &fds->readfds);
if (fd > fds->maxfd)
fds->maxfd = fd;
item = calloc(sizeof(struct fds_item), 1);
if (item == NULL)
return -1;
item->fd = fd;
item->cb = cb;
item->data = data;
/* Order matters: the descriptors are served in FIFO basis. */
list_add_tail(&item->head, &fds->list);
return 0;
}
int unregister_fd(int fd, struct fds *fds)
{
int found = 0, maxfd = -1;
struct fds_item *this, *tmp;
list_for_each_entry_safe(this, tmp, &fds->list, head) {
if (this->fd == fd) {
list_del(&this->head);
FD_CLR(this->fd, &fds->readfds);
free(this);
found = 1;
/* ... and recalculate maxfd, see below. */
}
}
/* not found, report an error. */
if (!found)
return -1;
/* calculate the new maximum fd. */
list_for_each_entry(this, &fds->list, head) {
if (maxfd < this->fd) {
maxfd = this->fd;
}
}
fds->maxfd = maxfd;
return 0;
}
static void select_main_step(struct timeval *next_alarm)
{
int ret;
fd_set readfds = STATE(fds)->readfds;
struct fds_item *cur, *tmp;
ret = select(STATE(fds)->maxfd + 1, &readfds, NULL, NULL, next_alarm);
if (ret == -1) {
/* interrupted syscall, retry */
if (errno == EINTR)
return;
STATE(stats).select_failed++;
return;
}
/* signals are racy */
sigprocmask(SIG_BLOCK, &STATE(block), NULL);
list_for_each_entry_safe(cur, tmp, &STATE(fds)->list, head) {
if (FD_ISSET(cur->fd, &readfds))
cur->cb(cur->data);
}
sigprocmask(SIG_UNBLOCK, &STATE(block), NULL);
}
void __attribute__((noreturn)) select_main_loop(void)
{
struct timeval next_alarm;
struct timeval *next = NULL;
while(1) {
do_gettimeofday();
sigprocmask(SIG_BLOCK, &STATE(block), NULL);
if (next != NULL && !timerisset(next))
next = do_alarm_run(&next_alarm);
else
next = get_next_alarm_run(&next_alarm);
sigprocmask(SIG_UNBLOCK, &STATE(block), NULL);
select_main_step(next);
}
}
|
