ngx_http_proxy_module.c

nginx 反向代理0.7.1版本 用于实现反向代理

/*
 * Copyright (C) Igor Sysoev
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_event.h>
#include <ngx_http.h>


typedef struct ngx_http_proxy_redirect_s  ngx_http_proxy_redirect_t;

typedef ngx_int_t (*ngx_http_proxy_redirect_pt)(ngx_http_request_t *r,
    ngx_table_elt_t *h, size_t prefix, ngx_http_proxy_redirect_t *pr);

struct ngx_http_proxy_redirect_s {
    ngx_http_proxy_redirect_pt     handler;
    ngx_str_t                      redirect;

    union {
        ngx_str_t                  text;

        struct {
            void                  *lengths;
            void                  *values;
        } vars;

        void                      *regex;
    } replacement;
};


typedef struct {
    ngx_str_t                      host_header;
    ngx_str_t                      port;
    ngx_str_t                      uri;
} ngx_http_proxy_vars_t;


typedef struct {
    ngx_http_upstream_conf_t       upstream;

    ngx_array_t                   *flushes;
    ngx_array_t                   *body_set_len;
    ngx_array_t                   *body_set;
    ngx_array_t                   *headers_set_len;
    ngx_array_t                   *headers_set;
    ngx_hash_t                     headers_set_hash;

    ngx_array_t                   *headers_source;
    ngx_array_t                   *headers_names;

    ngx_array_t                   *proxy_lengths;
    ngx_array_t                   *proxy_values;

    ngx_array_t                   *redirects;

    ngx_str_t                      body_source;

    ngx_str_t                      method;
    ngx_str_t                      location;
    ngx_str_t                      url;

    ngx_http_proxy_vars_t          vars;

    ngx_flag_t                     redirect;

    ngx_uint_t                     headers_hash_max_size;
    ngx_uint_t                     headers_hash_bucket_size;
} ngx_http_proxy_loc_conf_t;


typedef struct {
    ngx_uint_t                     status;
    ngx_uint_t                     status_count;
    u_char                        *status_start;
    u_char                        *status_end;

    ngx_http_proxy_vars_t          vars;

    size_t                         internal_body_length;
} ngx_http_proxy_ctx_t;


#define NGX_HTTP_PROXY_PARSE_NO_HEADER  20


static ngx_int_t ngx_http_proxy_eval(ngx_http_request_t *r,
    ngx_http_proxy_ctx_t *ctx, ngx_http_proxy_loc_conf_t *plcf);
static ngx_int_t ngx_http_proxy_create_request(ngx_http_request_t *r);
static ngx_int_t ngx_http_proxy_reinit_request(ngx_http_request_t *r);
static ngx_int_t ngx_http_proxy_process_status_line(ngx_http_request_t *r);
static ngx_int_t ngx_http_proxy_parse_status_line(ngx_http_request_t *r,
    ngx_http_proxy_ctx_t *ctx);
static ngx_int_t ngx_http_proxy_process_header(ngx_http_request_t *r);
static void ngx_http_proxy_abort_request(ngx_http_request_t *r);
static void ngx_http_proxy_finalize_request(ngx_http_request_t *r,
    ngx_int_t rc);

static ngx_int_t ngx_http_proxy_host_variable(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_proxy_port_variable(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t
    ngx_http_proxy_add_x_forwarded_for_variable(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t
    ngx_http_proxy_internal_body_length_variable(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_proxy_rewrite_redirect(ngx_http_request_t *r,
    ngx_table_elt_t *h, size_t prefix);

static ngx_int_t ngx_http_proxy_add_variables(ngx_conf_t *cf);
static void *ngx_http_proxy_create_loc_conf(ngx_conf_t *cf);
static char *ngx_http_proxy_merge_loc_conf(ngx_conf_t *cf,
    void *parent, void *child);

static char *ngx_http_proxy_pass(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static char *ngx_http_proxy_redirect(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static char *ngx_http_proxy_store(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);

static char *ngx_http_proxy_lowat_check(ngx_conf_t *cf, void *post, void *data);

static char *ngx_http_proxy_upstream_max_fails_unsupported(ngx_conf_t *cf,
    ngx_command_t *cmd, void *conf);
static char *ngx_http_proxy_upstream_fail_timeout_unsupported(ngx_conf_t *cf,
    ngx_command_t *cmd, void *conf);

#if (NGX_HTTP_SSL)
static ngx_int_t ngx_http_proxy_set_ssl(ngx_conf_t *cf,
    ngx_http_proxy_loc_conf_t *plcf);
#endif
static ngx_int_t ngx_http_proxy_set_vars(ngx_pool_t *pool, ngx_url_t *u,
    ngx_http_proxy_vars_t *v);


static ngx_conf_post_t  ngx_http_proxy_lowat_post =
    { ngx_http_proxy_lowat_check };


static ngx_conf_bitmask_t  ngx_http_proxy_next_upstream_masks[] = {
    { ngx_string("error"), NGX_HTTP_UPSTREAM_FT_ERROR },
    { ngx_string("timeout"), NGX_HTTP_UPSTREAM_FT_TIMEOUT },
    { ngx_string("invalid_header"), NGX_HTTP_UPSTREAM_FT_INVALID_HEADER },
    { ngx_string("http_500"), NGX_HTTP_UPSTREAM_FT_HTTP_500 },
    { ngx_string("http_503"), NGX_HTTP_UPSTREAM_FT_HTTP_503 },
    { ngx_string("http_404"), NGX_HTTP_UPSTREAM_FT_HTTP_404 },
    { ngx_string("off"), NGX_HTTP_UPSTREAM_FT_OFF },
    { ngx_null_string, 0 }
};


static ngx_command_t  ngx_http_proxy_commands[] = {

    { ngx_string("proxy_pass"),
      NGX_HTTP_LOC_CONF|NGX_HTTP_LIF_CONF|NGX_HTTP_LMT_CONF|NGX_CONF_TAKE1,
      ngx_http_proxy_pass,
      NGX_HTTP_LOC_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("proxy_redirect"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE12,
      ngx_http_proxy_redirect,
      NGX_HTTP_LOC_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("proxy_store"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_http_proxy_store,
      NGX_HTTP_LOC_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("proxy_store_access"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE123,
      ngx_conf_set_access_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_proxy_loc_conf_t, upstream.store_access),
      NULL },

    { ngx_string("proxy_buffering"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
      ngx_conf_set_flag_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_proxy_loc_conf_t, upstream.buffering),
      NULL },

    { ngx_string("proxy_ignore_client_abort"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
      ngx_conf_set_flag_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_proxy_loc_conf_t, upstream.ignore_client_abort),
      NULL },

    { ngx_string("proxy_connect_timeout"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_msec_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_proxy_loc_conf_t, upstream.connect_timeout),
      NULL },

    { ngx_string("proxy_send_timeout"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_msec_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_proxy_loc_conf_t, upstream.send_timeout),
      NULL },

    { ngx_string("proxy_send_lowat"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_proxy_loc_conf_t, upstream.send_lowat),
      &ngx_http_proxy_lowat_post },

    { ngx_string("proxy_intercept_errors"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
      ngx_conf_set_flag_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_proxy_loc_conf_t, upstream.intercept_errors),
      NULL },

    { ngx_string("proxy_set_header"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE2,
      ngx_conf_set_keyval_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_proxy_loc_conf_t, headers_source),
      NULL },

    { ngx_string("proxy_headers_hash_max_size"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_num_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_proxy_loc_conf_t, headers_hash_max_size),
      NULL },

    { ngx_string("proxy_headers_hash_bucket_size"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_num_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_proxy_loc_conf_t, headers_hash_bucket_size),
      NULL },

    { ngx_string("proxy_set_body"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_str_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_proxy_loc_conf_t, body_source),
      NULL },

    { ngx_string("proxy_method"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_str_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_proxy_loc_conf_t, method),
      NULL },

    { ngx_string("proxy_pass_request_headers"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
      ngx_conf_set_flag_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_proxy_loc_conf_t, upstream.pass_request_headers),
      NULL },

    { ngx_string("proxy_pass_request_body"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
      ngx_conf_set_flag_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_proxy_loc_conf_t, upstream.pass_request_body),
      NULL },

    { ngx_string("proxy_buffer_size"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_proxy_loc_conf_t, upstream.buffer_size),
      NULL },

    { ngx_string("proxy_read_timeout"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_msec_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_proxy_loc_conf_t, upstream.read_timeout),
      NULL },

    { ngx_string("proxy_buffers"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE2,
      ngx_conf_set_bufs_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_proxy_loc_conf_t, upstream.bufs),
      NULL },

    { ngx_string("proxy_busy_buffers_size"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_proxy_loc_conf_t, upstream.busy_buffers_size_conf),
      NULL },

    { ngx_string("proxy_temp_path"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1234,
      ngx_conf_set_path_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_proxy_loc_conf_t, upstream.temp_path),
      (void *) ngx_garbage_collector_temp_handler },

    { ngx_string("proxy_max_temp_file_size"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_proxy_loc_conf_t, upstream.max_temp_file_size_conf),
      NULL },

    { ngx_string("proxy_temp_file_write_size"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_proxy_loc_conf_t, upstream.temp_file_write_size_conf),
      NULL },

    { ngx_string("proxy_next_upstream"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
      ngx_conf_set_bitmask_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_proxy_loc_conf_t, upstream.next_upstream),
      &ngx_http_proxy_next_upstream_masks },

    { ngx_string("proxy_upstream_max_fails"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_http_proxy_upstream_max_fails_unsupported,
      0,
      0,
      NULL },

    { ngx_string("proxy_upstream_fail_timeout"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_http_proxy_upstream_fail_timeout_unsupported,
      0,
      0,
      NULL },

    { ngx_string("proxy_pass_header"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
      ngx_conf_set_str_array_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_proxy_loc_conf_t, upstream.pass_headers),
      NULL },

    { ngx_string("proxy_hide_header"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
      ngx_conf_set_str_array_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_proxy_loc_conf_t, upstream.hide_headers),
      NULL },

      ngx_null_command
};


static ngx_http_module_t  ngx_http_proxy_module_ctx = {
    ngx_http_proxy_add_variables,          /* preconfiguration */
    NULL,                                  /* postconfiguration */

    NULL,                                  /* create main configuration */
    NULL,                                  /* init main configuration */

    NULL,                                  /* create server configuration */
    NULL,                                  /* merge server configuration */

    ngx_http_proxy_create_loc_conf,        /* create location configration */
    ngx_http_proxy_merge_loc_conf          /* merge location configration */
};


ngx_module_t  ngx_http_proxy_module = {
    NGX_MODULE_V1,
    &ngx_http_proxy_module_ctx,            /* module context */
    ngx_http_proxy_commands,               /* module directives */
    NGX_HTTP_MODULE,                       /* module type */
    NULL,                                  /* init master */
    NULL,                                  /* init module */
    NULL,                                  /* init process */
    NULL,                                  /* init thread */
    NULL,                                  /* exit thread */
    NULL,                                  /* exit process */
    NULL,                                  /* exit master */
    NGX_MODULE_V1_PADDING
};


static char  ngx_http_proxy_version[] = " HTTP/1.0" CRLF;


static ngx_keyval_t  ngx_http_proxy_headers[] = {
    { ngx_string("Host"), ngx_string("$proxy_host") },
    { ngx_string("Connection"), ngx_string("close") },
    { ngx_string("Keep-Alive"), ngx_string("") },
    { ngx_null_string, ngx_null_string }
};


static ngx_str_t  ngx_http_proxy_hide_headers[] = {
    ngx_string("Date"),
    ngx_string("Server"),
    ngx_string("X-Pad"),
    ngx_string("X-Accel-Expires"),
    ngx_string("X-Accel-Redirect"),
    ngx_string("X-Accel-Limit-Rate"),
    ngx_string("X-Accel-Buffering"),
    ngx_string("X-Accel-Charset"),
    ngx_null_string
};


static ngx_http_variable_t  ngx_http_proxy_vars[] = {

    { ngx_string("proxy_host"), NULL, ngx_http_proxy_host_variable, 0,
      NGX_HTTP_VAR_CHANGEABLE|NGX_HTTP_VAR_NOCACHEABLE|NGX_HTTP_VAR_NOHASH, 0 },

    { ngx_string("proxy_port"), NULL, ngx_http_proxy_port_variable, 0,
      NGX_HTTP_VAR_CHANGEABLE|NGX_HTTP_VAR_NOCACHEABLE|NGX_HTTP_VAR_NOHASH, 0 },

    { ngx_string("proxy_add_x_forwarded_for"), NULL,
      ngx_http_proxy_add_x_forwarded_for_variable, 0, NGX_HTTP_VAR_NOHASH, 0 },

#if 0
    { ngx_string("proxy_add_via"), NULL, NULL, 0, NGX_HTTP_VAR_NOHASH, 0 },
#endif

    { ngx_string("proxy_internal_body_length"), NULL,
      ngx_http_proxy_internal_body_length_variable, 0, NGX_HTTP_VAR_NOHASH, 0 },

    { ngx_null_string, NULL, NULL, 0, 0, 0 }
};


static ngx_int_t
ngx_http_proxy_handler(ngx_http_request_t *r)
{
    ngx_int_t                   rc;
    ngx_http_upstream_t        *u;
    ngx_http_proxy_ctx_t       *ctx;
    ngx_http_proxy_loc_conf_t  *plcf;

    u = ngx_pcalloc(r->pool, sizeof(ngx_http_upstream_t));
    if (u == NULL) {