1
2 /*
3 * Copyright (C) Igor Sysoev
4 * Copyright (C) Nginx, Inc.
5 */
6
7
8 #include <ngx_config.h>
9 #include <ngx_core.h>
10 #include <ngx_stream.h>
11
12
13 typedef struct {
14 uint32_t percent;
15 ngx_stream_variable_value_t value;
16 } ngx_stream_split_clients_part_t;
17
18
19 typedef struct {
20 ngx_stream_complex_value_t value;
21 ngx_array_t parts;
22 } ngx_stream_split_clients_ctx_t;
23
24
25 static char *ngx_conf_split_clients_block(ngx_conf_t *cf, ngx_command_t *cmd,
26 void *conf);
27 static char *ngx_stream_split_clients(ngx_conf_t *cf, ngx_command_t *dummy,
28 void *conf);
29
30 static ngx_command_t ngx_stream_split_clients_commands[] = {
31
32 { ngx_string("split_clients"),
33 NGX_STREAM_MAIN_CONF|NGX_CONF_BLOCK|NGX_CONF_TAKE2,
34 ngx_conf_split_clients_block,
35 NGX_STREAM_MAIN_CONF_OFFSET,
36 0,
37 NULL },
38
39 ngx_null_command
40 };
41
42
43 static ngx_stream_module_t ngx_stream_split_clients_module_ctx = {
44 NULL, /* preconfiguration */
45 NULL, /* postconfiguration */
46
47 NULL, /* create main configuration */
48 NULL, /* init main configuration */
49
50 NULL, /* create server configuration */
51 NULL /* merge server configuration */
52 };
53
54
55 ngx_module_t ngx_stream_split_clients_module = {
56 NGX_MODULE_V1,
57 &ngx_stream_split_clients_module_ctx, /* module context */
58 ngx_stream_split_clients_commands, /* module directives */
59 NGX_STREAM_MODULE, /* module type */
60 NULL, /* init master */
61 NULL, /* init module */
62 NULL, /* init process */
63 NULL, /* init thread */
64 NULL, /* exit thread */
65 NULL, /* exit process */
66 NULL, /* exit master */
67 NGX_MODULE_V1_PADDING
68 };
69
70
71 static ngx_int_t
ngx_stream_split_clients_variable(ngx_stream_session_t * s,ngx_stream_variable_value_t * v,uintptr_t data)72 ngx_stream_split_clients_variable(ngx_stream_session_t *s,
73 ngx_stream_variable_value_t *v, uintptr_t data)
74 {
75 ngx_stream_split_clients_ctx_t *ctx =
76 (ngx_stream_split_clients_ctx_t *) data;
77
78 uint32_t hash;
79 ngx_str_t val;
80 ngx_uint_t i;
81 ngx_stream_split_clients_part_t *part;
82
83 *v = ngx_stream_variable_null_value;
84
85 if (ngx_stream_complex_value(s, &ctx->value, &val) != NGX_OK) {
86 return NGX_OK;
87 }
88
89 hash = ngx_murmur_hash2(val.data, val.len);
90
91 part = ctx->parts.elts;
92
93 for (i = 0; i < ctx->parts.nelts; i++) {
94
95 ngx_log_debug2(NGX_LOG_DEBUG_STREAM, s->connection->log, 0,
96 "stream split: %uD %uD", hash, part[i].percent);
97
98 if (hash < part[i].percent || part[i].percent == 0) {
99 *v = part[i].value;
100 return NGX_OK;
101 }
102 }
103
104 return NGX_OK;
105 }
106
107
108 static char *
ngx_conf_split_clients_block(ngx_conf_t * cf,ngx_command_t * cmd,void * conf)109 ngx_conf_split_clients_block(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
110 {
111 char *rv;
112 uint32_t sum, last;
113 ngx_str_t *value, name;
114 ngx_uint_t i;
115 ngx_conf_t save;
116 ngx_stream_variable_t *var;
117 ngx_stream_split_clients_ctx_t *ctx;
118 ngx_stream_split_clients_part_t *part;
119 ngx_stream_compile_complex_value_t ccv;
120
121 ctx = ngx_pcalloc(cf->pool, sizeof(ngx_stream_split_clients_ctx_t));
122 if (ctx == NULL) {
123 return NGX_CONF_ERROR;
124 }
125
126 value = cf->args->elts;
127
128 ngx_memzero(&ccv, sizeof(ngx_stream_compile_complex_value_t));
129
130 ccv.cf = cf;
131 ccv.value = &value[1];
132 ccv.complex_value = &ctx->value;
133
134 if (ngx_stream_compile_complex_value(&ccv) != NGX_OK) {
135 return NGX_CONF_ERROR;
136 }
137
138 name = value[2];
139
140 if (name.data[0] != '$') {
141 ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
142 "invalid variable name \"%V\"", &name);
143 return NGX_CONF_ERROR;
144 }
145
146 name.len--;
147 name.data++;
148
149 var = ngx_stream_add_variable(cf, &name, NGX_STREAM_VAR_CHANGEABLE);
150 if (var == NULL) {
151 return NGX_CONF_ERROR;
152 }
153
154 var->get_handler = ngx_stream_split_clients_variable;
155 var->data = (uintptr_t) ctx;
156
157 if (ngx_array_init(&ctx->parts, cf->pool, 2,
158 sizeof(ngx_stream_split_clients_part_t))
159 != NGX_OK)
160 {
161 return NGX_CONF_ERROR;
162 }
163
164 save = *cf;
165 cf->ctx = ctx;
166 cf->handler = ngx_stream_split_clients;
167 cf->handler_conf = conf;
168
169 rv = ngx_conf_parse(cf, NULL);
170
171 *cf = save;
172
173 if (rv != NGX_CONF_OK) {
174 return rv;
175 }
176
177 sum = 0;
178 last = 0;
179 part = ctx->parts.elts;
180
181 for (i = 0; i < ctx->parts.nelts; i++) {
182 sum = part[i].percent ? sum + part[i].percent : 10000;
183 if (sum > 10000) {
184 ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
185 "percent total is greater than 100%%");
186 return NGX_CONF_ERROR;
187 }
188
189 if (part[i].percent) {
190 last += part[i].percent * (uint64_t) 0xffffffff / 10000;
191 part[i].percent = last;
192 }
193 }
194
195 return rv;
196 }
197
198
199 static char *
ngx_stream_split_clients(ngx_conf_t * cf,ngx_command_t * dummy,void * conf)200 ngx_stream_split_clients(ngx_conf_t *cf, ngx_command_t *dummy, void *conf)
201 {
202 ngx_int_t n;
203 ngx_str_t *value;
204 ngx_stream_split_clients_ctx_t *ctx;
205 ngx_stream_split_clients_part_t *part;
206
207 ctx = cf->ctx;
208 value = cf->args->elts;
209
210 part = ngx_array_push(&ctx->parts);
211 if (part == NULL) {
212 return NGX_CONF_ERROR;
213 }
214
215 if (value[0].len == 1 && value[0].data[0] == '*') {
216 part->percent = 0;
217
218 } else {
219 if (value[0].len == 0 || value[0].data[value[0].len - 1] != '%') {
220 goto invalid;
221 }
222
223 n = ngx_atofp(value[0].data, value[0].len - 1, 2);
224 if (n == NGX_ERROR || n == 0) {
225 goto invalid;
226 }
227
228 part->percent = (uint32_t) n;
229 }
230
231 part->value.len = value[1].len;
232 part->value.valid = 1;
233 part->value.no_cacheable = 0;
234 part->value.not_found = 0;
235 part->value.data = value[1].data;
236
237 return NGX_CONF_OK;
238
239 invalid:
240
241 ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
242 "invalid percent value \"%V\"", &value[0]);
243 return NGX_CONF_ERROR;
244 }
245