nginx/src/http/modules/ngx_http_addition_filter_module.c

   1
   2 /*
   3  * Copyright (C) Igor Sysoev
   4  */
   5
   6
   7 #include <ngx_config.h>
   8 #include <ngx_core.h>
   9 #include <ngx_http.h>
  10
  11
  12 typedef struct {
  13     ngx_str_t     before_body;
  14     ngx_str_t     after_body;
  15
  16     ngx_hash_t    types;
  17     ngx_array_t  *types_keys;
  18 } ngx_http_addition_conf_t;
  19
  20
  21 typedef struct {
  22     ngx_uint_t    before_body_sent;
  23 } ngx_http_addition_ctx_t;
  24
  25
  26 static void *ngx_http_addition_create_conf(ngx_conf_t *cf);
  27 static char *ngx_http_addition_merge_conf(ngx_conf_t *cf, void *parent,
  28     void *child);
  29 static ngx_int_t ngx_http_addition_filter_init(ngx_conf_t *cf);
  30
  31
  32 static ngx_command_t  ngx_http_addition_commands[] = {
  33
  34     { ngx_string("add_before_body"),
  35       NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
  36       ngx_conf_set_str_slot,
  37       NGX_HTTP_LOC_CONF_OFFSET,
  38       offsetof(ngx_http_addition_conf_t, before_body),
  39       NULL },
  40
  41     { ngx_string("add_after_body"),
  42       NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
  43       ngx_conf_set_str_slot,
  44       NGX_HTTP_LOC_CONF_OFFSET,
  45       offsetof(ngx_http_addition_conf_t, after_body),
  46       NULL },
  47
  48     { ngx_string("addtion_types"),
  49       NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
  50       ngx_http_types_slot,
  51       NGX_HTTP_LOC_CONF_OFFSET,
  52       offsetof(ngx_http_addition_conf_t, types_keys),
  53       &ngx_http_html_default_types[0] },
  54
  55       ngx_null_command
  56 };
  57
  58
  59 static ngx_http_module_t  ngx_http_addition_filter_module_ctx = {
  60     NULL,                                  /* preconfiguration */
  61     ngx_http_addition_filter_init,         /* postconfiguration */
  62
  63     NULL,                                  /* create main configuration */
  64     NULL,                                  /* init main configuration */
  65
  66     NULL,                                  /* create server configuration */
  67     NULL,                                  /* merge server configuration */
  68
  69     ngx_http_addition_create_conf,         /* create location configuration */
  70     ngx_http_addition_merge_conf           /* merge location configuration */
  71 };
  72
  73
  74 ngx_module_t  ngx_http_addition_filter_module = {
  75     NGX_MODULE_V1,
  76     &ngx_http_addition_filter_module_ctx,  /* module context */
  77     ngx_http_addition_commands,            /* module directives */
  78     NGX_HTTP_MODULE,                       /* module type */
  79     NULL,                                  /* init master */
  80     NULL,                                  /* init module */
  81     NULL,                                  /* init process */
  82     NULL,                                  /* init thread */
  83     NULL,                                  /* exit thread */
  84     NULL,                                  /* exit process */
  85     NULL,                                  /* exit master */
  86     NGX_MODULE_V1_PADDING
  87 };
  88
  89
  90 static ngx_http_output_header_filter_pt  ngx_http_next_header_filter;
  91 static ngx_http_output_body_filter_pt    ngx_http_next_body_filter;
  92
  93
  94 static ngx_int_t
  95 ngx_http_addition_header_filter(ngx_http_request_t *r)
  96 {
  97     ngx_http_addition_ctx_t   *ctx;
  98     ngx_http_addition_conf_t  *conf;
  99
 100     if (r->headers_out.status != NGX_HTTP_OK || r != r->main) {
 101         return ngx_http_next_header_filter(r);
 102     }
 103
 104     conf = ngx_http_get_module_loc_conf(r, ngx_http_addition_filter_module);
 105
 106     if (conf->before_body.len == 0 && conf->after_body.len == 0) {
 107         return ngx_http_next_header_filter(r);
 108     }
 109
 110     if (ngx_http_test_content_type(r, &conf->types) == NULL) {
 111         return ngx_http_next_header_filter(r);
 112     }
 113
 114     ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_addition_ctx_t));
 115     if (ctx == NULL) {
 116         return NGX_ERROR;
 117     }
 118
 119     ngx_http_set_ctx(r, ctx, ngx_http_addition_filter_module);
 120
 121     ngx_http_clear_content_length(r);
 122     ngx_http_clear_accept_ranges(r);
 123
 124     return ngx_http_next_header_filter(r);
 125 }
 126
 127
 128 static ngx_int_t
 129 ngx_http_addition_body_filter(ngx_http_request_t *r, ngx_chain_t *in)
 130 {
 131     ngx_int_t                  rc;
 132     ngx_uint_t                 last;
 133     ngx_chain_t               *cl;
 134     ngx_http_request_t        *sr;
 135     ngx_http_addition_ctx_t   *ctx;
 136     ngx_http_addition_conf_t  *conf;
 137
 138     if (in == NULL || r->header_only) {
 139         return ngx_http_next_body_filter(r, in);
 140     }
 141
 142     ctx = ngx_http_get_module_ctx(r, ngx_http_addition_filter_module);
 143
 144     if (ctx == NULL) {
 145         return ngx_http_next_body_filter(r, in);
 146     }
 147
 148     conf = ngx_http_get_module_loc_conf(r, ngx_http_addition_filter_module);
 149
 150     if (!ctx->before_body_sent) {
 151         ctx->before_body_sent = 1;
 152
 153         if (conf->before_body.len) {
 154             if (ngx_http_subrequest(r, &conf->before_body, NULL, &sr, NULL, 0)
 155                 != NGX_OK)
 156             {
 157                 return NGX_ERROR;
 158             }
 159         }
 160     }
 161
 162     if (conf->after_body.len == 0) {
 163         ngx_http_set_ctx(r, NULL, ngx_http_addition_filter_module);
 164         return ngx_http_next_body_filter(r, in);
 165     }
 166
 167     last = 0;
 168
 169     for (cl = in; cl; cl = cl->next) {
 170         if (cl->buf->last_buf) {
 171             cl->buf->last_buf = 0;
 172             cl->buf->sync = 1;
 173             last = 1;
 174         }
 175     }
 176
 177     rc = ngx_http_next_body_filter(r, in);
 178
 179     if (rc == NGX_ERROR || !last || conf->after_body.len == 0) {
 180         return rc;
 181     }
 182
 183     if (ngx_http_subrequest(r, &conf->after_body, NULL, &sr, NULL, 0)
 184         != NGX_OK)
 185     {
 186         return NGX_ERROR;
 187     }
 188
 189     ngx_http_set_ctx(r, NULL, ngx_http_addition_filter_module);
 190
 191     return ngx_http_send_special(r, NGX_HTTP_LAST);
 192 }
 193
 194
 195 static ngx_int_t
 196 ngx_http_addition_filter_init(ngx_conf_t *cf)
 197 {
 198     ngx_http_next_header_filter = ngx_http_top_header_filter;
 199     ngx_http_top_header_filter = ngx_http_addition_header_filter;
 200
 201     ngx_http_next_body_filter = ngx_http_top_body_filter;
 202     ngx_http_top_body_filter = ngx_http_addition_body_filter;
 203
 204     return NGX_OK;
 205 }
 206
 207
 208 static void *
 209 ngx_http_addition_create_conf(ngx_conf_t *cf)
 210 {
 211     ngx_http_addition_conf_t  *conf;
 212
 213     conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_addition_conf_t));
 214     if (conf == NULL) {
 215         return NGX_CONF_ERROR;
 216     }
 217
 218     /*
 219      * set by ngx_pcalloc():
 220      *
 221      *     conf->before_body = { 0, NULL };
 222      *     conf->after_body = { 0, NULL };
 223      *     conf->types = { NULL };
 224      *     conf->types_keys = NULL;
 225      */
 226
 227     return conf;
 228 }
 229
 230
 231 static char *
 232 ngx_http_addition_merge_conf(ngx_conf_t *cf, void *parent, void *child)
 233 {
 234     ngx_http_addition_conf_t *prev = parent;
 235     ngx_http_addition_conf_t *conf = child;
 236
 237     ngx_conf_merge_str_value(conf->before_body, prev->before_body, "");
 238     ngx_conf_merge_str_value(conf->after_body, prev->after_body, "");
 239
 240     if (ngx_http_merge_types(cf, conf->types_keys, &conf->types,
 241                              prev->types_keys, &prev->types,
 242                              ngx_http_html_default_types)
 243         != NGX_OK)
 244     {
 245         return NGX_CONF_ERROR;
 246     }
 247
 248     return NGX_CONF_OK;
 249 }