Nginx-Filtermodul
Entwicklungsschritte des HTTP-Filtermoduls
Konfigurationsdatei nginx.conf
<code>ngx_add HTTP_FILTER_MODULES=<span>"<span>$HTTP_FILTER_MODULES</span> ngx_http_myfilter_module"</span> NGX_ADD>"<span>$NGX_ADDON_SRCS</span><span>$ngx_addon_dir</span>/ngx_http_myfilter_module.c"</code>
add_prefix on;
Filtermodul aktivieren<code><span>#include <../src/core/ngx_config.h></span><span>#include <../src/core/ngx_core.h></span><span>#include <../src/http/ngx_http.h></span><span>//Declare</span><span>static</span> ngx_int_t ngx_http_myfilter_header_filter(ngx_http_request_t *); <span>static</span> ngx_int_t ngx_http_myfilter_body_filter(ngx_http_request_t*,ngx_chain_t*); <span>static</span> ngx_http_output_header_filter_pt ngx_http_next_header_filter; <span>static</span> ngx_http_output_body_filter_pt ngx_http_next_body_filter; <span>//On/Off</span><span>typedef</span><span>struct</span> { ngx_flag_t enable; }ngx_http_myfilter_conf_t; <span>static</span><span>void</span> *ngx_http_myfilter_create_conf(ngx_conf_t *cf){ ngx_http_myfilter_conf_t *mycf; <span>//Allocate memory</span> mycf = (ngx_http_myfilter_conf_t*)ngx_pcalloc(cf->pool,<span>sizeof</span>(ngx_http_myfilter_conf_t)); <span>if</span>(mycf == <span>NULL</span>) <span>return</span><span>NULL</span>; mycf->enable = NGX_CONF_UNSET; <span>return</span> mycf; } <span>static</span><span>char</span> * ngx_http_myfilter_merge_conf(ngx_conf_t *cf,<span>void</span> *parent,<span>void</span> *child){ ngx_http_myfilter_conf_t *prev = (ngx_http_myfilter_conf_t*)parent; ngx_http_myfilter_conf_t *conf = (ngx_http_myfilter_conf_t*)child; ngx_conf_merge_value(conf->enable,prev->enable,<span>0</span>); <span>return</span> NGX_CONF_OK; } <span>/* ------------------------------------------- */</span><span>//State for prefix</span><span>typedef</span><span>struct</span> { <span>/* add_prefix = * 0 the filter module is off * 1 can add prefix * 2 has been added prefix already */</span> ngx_int_t add_prefix; } ngx_http_myfilter_ctx_t; <span>//Analyse configure</span><span>static</span> ngx_command_t ngx_http_myfilter_commands[]={ {ngx_string(<span>"add_prefix"</span>), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_HTTP_LMT_CONF|NGX_CONF_FLAG, ngx_conf_set_flag_slot, NGX_HTTP_LOC_CONF_OFFSET, offsetof(ngx_http_myfilter_conf_t,enable), <span>NULL</span>}, ngx_null_command }; <span>static</span> ngx_int_t ngx_http_myfilter_init(ngx_conf_t *cf){ <span>//Insert before the first node</span> ngx_http_next_header_filter = ngx_http_top_header_filter; ngx_http_top_header_filter = ngx_http_myfilter_header_filter; ngx_http_next_body_filter = ngx_http_top_body_filter; ngx_http_top_body_filter = ngx_http_myfilter_body_filter; <span>return</span> NGX_OK; } <span>/* ------------------------------------------- */</span><span>//Parse</span><span>static</span> ngx_http_module_t ngx_http_myfilter_module_ctx = { <span>NULL</span>, ngx_http_myfilter_init, <span>NULL</span>, <span>NULL</span>, <span>NULL</span>, <span>NULL</span>, ngx_http_myfilter_create_conf, ngx_http_myfilter_merge_conf }; <span>/* ------------------------------------------- */</span><span>//Module information</span> ngx_module_t ngx_http_myfilter_module = { NGX_MODULE_V1, &ngx_http_myfilter_module_ctx, ngx_http_myfilter_commands, NGX_HTTP_MODULE, <span>NULL</span>, <span>NULL</span>, <span>NULL</span>, <span>NULL</span>, <span>NULL</span>, <span>NULL</span>, <span>NULL</span>, NGX_MODULE_V1_PADDING }; <span>/* ------------------------------------------- */</span><span>static</span> ngx_str_t filter_prefix = ngx_string(<span>"[my filter module]"</span>); <span>//Filter to process the header</span><span>static</span> ngx_int_t ngx_http_myfilter_header_filter(ngx_http_request_t *r){ ngx_http_myfilter_ctx_t *ctx; ngx_http_myfilter_conf_t *conf; <span>if</span>(r->headers_out<span>.status</span> != NGX_HTTP_OK){ <span>return</span> ngx_http_next_header_filter(r); } <span>//Get context</span> ctx = ngx_http_get_module_ctx(r,ngx_http_myfilter_module); <span>if</span>(ctx){ <span>return</span> ngx_http_next_header_filter(r); } <span>//Get configure by ngx_http_myfilter_conf_t</span> conf = ngx_http_get_module_loc_conf(r,ngx_http_myfilter_module); <span>if</span>(conf->enable == <span>0</span>){<span>//add_prefix off</span><span>return</span> ngx_http_next_header_filter(r); } <span>//Create ngx_http_myfilter_ctx_t</span> ctx = ngx_pcalloc(r->pool,<span>sizeof</span>(ngx_http_myfilter_ctx_t)); <span>if</span>(ctx == <span>NULL</span>){ <span>return</span> NGX_ERROR; } <span>//add_prefix = 0 express do not add prefix</span> ctx->add_prefix = <span>0</span>; <span>//Set context</span> ngx_http_set_ctx(r,ctx,ngx_http_myfilter_module); <span>//myfilter module only figure out Content-Type="text/plain"</span><span>if</span>(r->headers_out<span>.content_type</span><span>.len</span>>=<span>sizeof</span>(<span>"text/plain"</span>) - <span>1</span> && ngx_strncasecmp(r->headers_out<span>.content_type</span><span>.data</span>,(u_char*)<span>"text/plain"</span>,<span>sizeof</span>(<span>"text/plain"</span>)-<span>1</span>)==<span>0</span>){ <span>//Set add_prefix</span> ctx->add_prefix = <span>1</span>; <span>if</span>(r->headers_out<span>.content_length_n</span>><span>0</span>) r->headers_out<span>.content_length_n</span> += filter_prefix<span>.len</span>; } <span>return</span> ngx_http_next_header_filter(r); } <span>//Filter to process the body</span><span>static</span> ngx_int_t ngx_http_myfilter_body_filter(ngx_http_request_t *r,ngx_chain_t *in){ ngx_http_myfilter_ctx_t *ctx; ctx = ngx_http_get_module_ctx(r,ngx_http_myfilter_module); <span>//If cannot get context or the add_prefix is 0/2,do not process</span><span>if</span>(ctx == <span>NULL</span> || ctx->add_prefix !=<span>1</span>) <span>return</span> ngx_http_next_body_filter(r,in); <span>//To make sure never add prefix again</span> ctx->add_prefix = <span>2</span>; <span>//Get prefix string</span> ngx_buf_t *b = ngx_create_temp_buf(r->pool,filter_prefix<span>.len</span>); b->start = b->pos = filter_prefix<span>.data</span>; b->last = b->pos + filter_prefix<span>.len</span>; <span>//Get and set ngx_chain_t list at the bginning</span> ngx_chain_t *cl = ngx_alloc_chain_link(r->pool); cl->buf = b; cl->next = in; <span>return</span> ngx_http_next_body_filter(r,cl); }</code>
Kompilieren
Das HTTP-Filtermodul ist ebenfalls ein HTTP-Modul, daher ist die Schreibweise des HTTP-Moduls ungefähr gleich.
<code>./configure --<span>add</span>-<span>module</span>=模块路径/ make make install</code>
Das Obige hat die Entwicklung des Nginx-HTTP-Filtermoduls einschließlich seiner Aspekte vorgestellt. Ich hoffe, dass es für Freunde hilfreich sein wird, die sich für PHP-Tutorials interessieren.