1 /**
2 * collectd - src/synproxy.c
3 * Copyright (C) 2017 Marek Becka
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; only version 2 of the License is applicable.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 *
18 * Authors:
19 * Marek Becka <https://github.com/marekbecka>
20 **/
21
22 #include "collectd.h"
23
24 #include "plugin.h"
25 #include "utils/common/common.h"
26
27 #if !KERNEL_LINUX
28 #error "No applicable input method."
29 #endif
30
31 #define SYNPROXY_FIELDS 6
32
33 static const char *synproxy_stat_path = "/proc/net/stat/synproxy";
34
35 static const char *column_names[SYNPROXY_FIELDS] = {
36 "entries", "syn_received", "invalid",
37 "valid", "retransmission", "reopened"};
38 static const char *column_types[SYNPROXY_FIELDS] = {
39 "current_connections", "connections", "cookies", "cookies", "cookies",
40 "connections"};
41
synproxy_submit(value_t * results)42 static void synproxy_submit(value_t *results) {
43 value_list_t vl = VALUE_LIST_INIT;
44
45 /* 1st column (entries) is hardcoded to 0 in kernel code */
46 for (size_t n = 1; n < SYNPROXY_FIELDS; n++) {
47 vl.values = &results[n];
48 vl.values_len = 1;
49
50 sstrncpy(vl.plugin, "synproxy", sizeof(vl.plugin));
51 sstrncpy(vl.type, column_types[n], sizeof(vl.type));
52 sstrncpy(vl.type_instance, column_names[n], sizeof(vl.type_instance));
53
54 plugin_dispatch_values(&vl);
55 }
56 }
57
synproxy_read(void)58 static int synproxy_read(void) {
59 char buf[1024];
60 value_t results[SYNPROXY_FIELDS];
61 int is_header = 1, status = 0;
62
63 FILE *fh = fopen(synproxy_stat_path, "r");
64 if (fh == NULL) {
65 ERROR("synproxy plugin: unable to open %s", synproxy_stat_path);
66 return -1;
67 }
68
69 memset(results, 0, sizeof(results));
70
71 while (fgets(buf, sizeof(buf), fh) != NULL) {
72 char *fields[SYNPROXY_FIELDS], *endprt;
73
74 if (is_header) {
75 is_header = 0;
76 continue;
77 }
78
79 int numfields = strsplit(buf, fields, STATIC_ARRAY_SIZE(fields));
80 if (numfields != SYNPROXY_FIELDS) {
81 ERROR("synproxy plugin: unexpected number of columns in %s",
82 synproxy_stat_path);
83 status = -1;
84 break;
85 }
86
87 /* 1st column (entries) is hardcoded to 0 in kernel code */
88 for (size_t n = 1; n < SYNPROXY_FIELDS; n++) {
89 char *endptr = NULL;
90 errno = 0;
91
92 results[n].derive += strtoull(fields[n], &endprt, 16);
93 if ((endptr == fields[n]) || errno != 0) {
94 ERROR("synproxy plugin: unable to parse value: %s", fields[n]);
95 fclose(fh);
96 return -1;
97 }
98 }
99 }
100
101 fclose(fh);
102
103 if (status == 0) {
104 synproxy_submit(results);
105 }
106
107 return status;
108 }
109
module_register(void)110 void module_register(void) {
111 plugin_register_read("synproxy", synproxy_read);
112 } /* void module_register */
113