1 /*
2 * Copyright (c) 2008-2013 Patrick McHardy <kaber@trash.net>
3 */
4
5 #include <stdio.h>
6 #include <string.h>
7 #include <stdlib.h>
8 #include <math.h>
9
10 #include <xtables.h>
11 #include <linux/netfilter/x_tables.h>
12 #include <linux/netfilter/xt_RATEEST.h>
13
14 struct rateest_tg_udata {
15 unsigned int interval;
16 unsigned int ewma_log;
17 };
18
19 static void
RATEEST_help(void)20 RATEEST_help(void)
21 {
22 printf(
23 "RATEEST target options:\n"
24 " --rateest-name name Rate estimator name\n"
25 " --rateest-interval sec Rate measurement interval in seconds\n"
26 " --rateest-ewmalog value Rate measurement averaging time constant\n");
27 }
28
29 enum {
30 O_NAME = 0,
31 O_INTERVAL,
32 O_EWMALOG,
33 };
34
35 #define s struct xt_rateest_target_info
36 static const struct xt_option_entry RATEEST_opts[] = {
37 {.name = "rateest-name", .id = O_NAME, .type = XTTYPE_STRING,
38 .flags = XTOPT_MAND | XTOPT_PUT, XTOPT_POINTER(s, name)},
39 {.name = "rateest-interval", .id = O_INTERVAL, .type = XTTYPE_STRING,
40 .flags = XTOPT_MAND},
41 {.name = "rateest-ewmalog", .id = O_EWMALOG, .type = XTTYPE_STRING,
42 .flags = XTOPT_MAND},
43 XTOPT_TABLEEND,
44 };
45 #undef s
46
47 /* Copied from iproute */
48 #define TIME_UNITS_PER_SEC 1000000
49
50 static int
RATEEST_get_time(unsigned int * time,const char * str)51 RATEEST_get_time(unsigned int *time, const char *str)
52 {
53 double t;
54 char *p;
55
56 t = strtod(str, &p);
57 if (p == str)
58 return -1;
59
60 if (*p) {
61 if (strcasecmp(p, "s") == 0 || strcasecmp(p, "sec")==0 ||
62 strcasecmp(p, "secs")==0)
63 t *= TIME_UNITS_PER_SEC;
64 else if (strcasecmp(p, "ms") == 0 || strcasecmp(p, "msec")==0 ||
65 strcasecmp(p, "msecs") == 0)
66 t *= TIME_UNITS_PER_SEC/1000;
67 else if (strcasecmp(p, "us") == 0 || strcasecmp(p, "usec")==0 ||
68 strcasecmp(p, "usecs") == 0)
69 t *= TIME_UNITS_PER_SEC/1000000;
70 else
71 return -1;
72 }
73
74 *time = t;
75 return 0;
76 }
77
78 static void
RATEEST_print_time(unsigned int time)79 RATEEST_print_time(unsigned int time)
80 {
81 double tmp = time;
82
83 if (tmp >= TIME_UNITS_PER_SEC)
84 printf(" %.1fs", tmp / TIME_UNITS_PER_SEC);
85 else if (tmp >= TIME_UNITS_PER_SEC/1000)
86 printf(" %.1fms", tmp / (TIME_UNITS_PER_SEC / 1000));
87 else
88 printf(" %uus", time);
89 }
90
RATEEST_parse(struct xt_option_call * cb)91 static void RATEEST_parse(struct xt_option_call *cb)
92 {
93 struct rateest_tg_udata *udata = cb->udata;
94
95 xtables_option_parse(cb);
96 switch (cb->entry->id) {
97 case O_INTERVAL:
98 if (RATEEST_get_time(&udata->interval, cb->arg) < 0)
99 xtables_error(PARAMETER_PROBLEM,
100 "RATEEST: bad interval value \"%s\"",
101 cb->arg);
102 break;
103 case O_EWMALOG:
104 if (RATEEST_get_time(&udata->ewma_log, cb->arg) < 0)
105 xtables_error(PARAMETER_PROBLEM,
106 "RATEEST: bad ewmalog value \"%s\"",
107 cb->arg);
108 break;
109 }
110 }
111
RATEEST_final_check(struct xt_fcheck_call * cb)112 static void RATEEST_final_check(struct xt_fcheck_call *cb)
113 {
114 struct xt_rateest_target_info *info = cb->data;
115 struct rateest_tg_udata *udata = cb->udata;
116
117 for (info->interval = 0; info->interval <= 5; info->interval++) {
118 if (udata->interval <= (1 << info->interval) * (TIME_UNITS_PER_SEC / 4))
119 break;
120 }
121
122 if (info->interval > 5)
123 xtables_error(PARAMETER_PROBLEM,
124 "RATEEST: interval value is too large");
125 info->interval -= 2;
126
127 for (info->ewma_log = 1; info->ewma_log < 32; info->ewma_log++) {
128 double w = 1.0 - 1.0 / (1 << info->ewma_log);
129 if (udata->interval / (-log(w)) > udata->ewma_log)
130 break;
131 }
132 info->ewma_log--;
133
134 if (info->ewma_log == 0 || info->ewma_log >= 31)
135 xtables_error(PARAMETER_PROBLEM,
136 "RATEEST: ewmalog value is out of range");
137 }
138
139 static void
__RATEEST_print(const struct xt_entry_target * target,const char * prefix)140 __RATEEST_print(const struct xt_entry_target *target, const char *prefix)
141 {
142 const struct xt_rateest_target_info *info = (const void *)target->data;
143 unsigned int local_interval;
144 unsigned int local_ewma_log;
145
146 local_interval = (TIME_UNITS_PER_SEC << (info->interval + 2)) / 4;
147 local_ewma_log = local_interval * (1 << (info->ewma_log));
148
149 printf(" %sname %s", prefix, info->name);
150 printf(" %sinterval", prefix);
151 RATEEST_print_time(local_interval);
152 printf(" %sewmalog", prefix);
153 RATEEST_print_time(local_ewma_log);
154 }
155
156 static void
RATEEST_print(const void * ip,const struct xt_entry_target * target,int numeric)157 RATEEST_print(const void *ip, const struct xt_entry_target *target,
158 int numeric)
159 {
160 __RATEEST_print(target, "");
161 }
162
163 static void
RATEEST_save(const void * ip,const struct xt_entry_target * target)164 RATEEST_save(const void *ip, const struct xt_entry_target *target)
165 {
166 __RATEEST_print(target, "--rateest-");
167 }
168
169 static struct xtables_target rateest_tg_reg = {
170 .family = NFPROTO_UNSPEC,
171 .name = "RATEEST",
172 .version = XTABLES_VERSION,
173 .size = XT_ALIGN(sizeof(struct xt_rateest_target_info)),
174 .userspacesize = offsetof(struct xt_rateest_target_info, est),
175 .help = RATEEST_help,
176 .x6_parse = RATEEST_parse,
177 .x6_fcheck = RATEEST_final_check,
178 .print = RATEEST_print,
179 .save = RATEEST_save,
180 .x6_options = RATEEST_opts,
181 .udata_size = sizeof(struct rateest_tg_udata),
182 };
183
_init(void)184 void _init(void)
185 {
186 xtables_register_target(&rateest_tg_reg);
187 }
188