ngx_http_ssi_filter_module.c

Nginx是一个高性能的HTTP和反向代理服务器

/*
 * Copyright (C) Igor Sysoev
 */


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

#define NGX_HTTP_SSI_ERROR          1

#define NGX_HTTP_SSI_DATE_LEN       2048

#define NGX_HTTP_SSI_ADD_PREFIX     1
#define NGX_HTTP_SSI_ADD_ZERO       2
#define NGX_HTTP_SSI_EXPR_TEST      4


typedef struct {
    ngx_flag_t    enable;
    ngx_flag_t    silent_errors;
    ngx_flag_t    ignore_recycled_buffers;

    ngx_array_t  *types;     /* array of ngx_str_t */

    size_t        min_file_chunk;
    size_t        value_len;
} ngx_http_ssi_loc_conf_t;


typedef struct {
    ngx_str_t     name;
    ngx_uint_t    key;
    ngx_str_t     value;
} ngx_http_ssi_var_t;


typedef struct {
    ngx_str_t     name;
    ngx_chain_t  *bufs;
    ngx_uint_t    count;
} ngx_http_ssi_block_t;


typedef enum {
    ssi_start_state = 0,
    ssi_tag_state,
    ssi_comment0_state,
    ssi_comment1_state,
    ssi_sharp_state,
    ssi_precommand_state,
    ssi_command_state,
    ssi_preparam_state,
    ssi_param_state,
    ssi_preequal_state,
    ssi_prevalue_state,
    ssi_double_quoted_value_state,
    ssi_quoted_value_state,
    ssi_quoted_symbol_state,
    ssi_postparam_state,
    ssi_comment_end0_state,
    ssi_comment_end1_state,
    ssi_error_state,
    ssi_error_end0_state,
    ssi_error_end1_state
} ngx_http_ssi_state_e;


static ngx_int_t ngx_http_ssi_output(ngx_http_request_t *r,
    ngx_http_ssi_ctx_t *ctx);
static ngx_int_t ngx_http_ssi_parse(ngx_http_request_t *r,
    ngx_http_ssi_ctx_t *ctx);
static ngx_str_t *ngx_http_ssi_get_variable(ngx_http_request_t *r,
    ngx_str_t *name, ngx_uint_t key);
static ngx_int_t ngx_http_ssi_evaluate_string(ngx_http_request_t *r,
    ngx_http_ssi_ctx_t *ctx, ngx_str_t *text, ngx_uint_t flags);

static ngx_int_t ngx_http_ssi_include(ngx_http_request_t *r,
    ngx_http_ssi_ctx_t *ctx, ngx_str_t **params);
static ngx_int_t ngx_http_ssi_stub_output(ngx_http_request_t *r, void *data,
    ngx_int_t rc);
static ngx_int_t ngx_http_ssi_set_variable(ngx_http_request_t *r, void *data,
    ngx_int_t rc);
static ngx_int_t ngx_http_ssi_echo(ngx_http_request_t *r,
    ngx_http_ssi_ctx_t *ctx, ngx_str_t **params);
static ngx_int_t ngx_http_ssi_config(ngx_http_request_t *r,
    ngx_http_ssi_ctx_t *ctx, ngx_str_t **params);
static ngx_int_t ngx_http_ssi_set(ngx_http_request_t *r,
    ngx_http_ssi_ctx_t *ctx, ngx_str_t **params);
static ngx_int_t ngx_http_ssi_if(ngx_http_request_t *r,
    ngx_http_ssi_ctx_t *ctx, ngx_str_t **params);
static ngx_int_t ngx_http_ssi_else(ngx_http_request_t *r,
    ngx_http_ssi_ctx_t *ctx, ngx_str_t **params);
static ngx_int_t ngx_http_ssi_endif(ngx_http_request_t *r,
    ngx_http_ssi_ctx_t *ctx, ngx_str_t **params);
static ngx_int_t ngx_http_ssi_block(ngx_http_request_t *r,
    ngx_http_ssi_ctx_t *ctx, ngx_str_t **params);
static ngx_int_t ngx_http_ssi_endblock(ngx_http_request_t *r,
    ngx_http_ssi_ctx_t *ctx, ngx_str_t **params);

static ngx_int_t ngx_http_ssi_date_gmt_local_variable(ngx_http_request_t *r,
    ngx_http_variable_value_t *v,  uintptr_t gmt);

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

static ngx_int_t ngx_http_ssi_preconfiguration(ngx_conf_t *cf);
static void *ngx_http_ssi_create_main_conf(ngx_conf_t *cf);
static char *ngx_http_ssi_init_main_conf(ngx_conf_t *cf, void *conf);
static void *ngx_http_ssi_create_loc_conf(ngx_conf_t *cf);
static char *ngx_http_ssi_merge_loc_conf(ngx_conf_t *cf,
    void *parent, void *child);
static ngx_int_t ngx_http_ssi_filter_init(ngx_conf_t *cf);


static ngx_command_t  ngx_http_ssi_filter_commands[] = {

    { ngx_string("ssi"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_HTTP_LIF_CONF
                        |NGX_CONF_FLAG,
      ngx_conf_set_flag_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_ssi_loc_conf_t, enable),
      NULL },

    { ngx_string("ssi_silent_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_ssi_loc_conf_t, silent_errors),
      NULL },

    { ngx_string("ssi_ignore_recycled_buffers"),
      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_ssi_loc_conf_t, ignore_recycled_buffers),
      NULL },

    { ngx_string("ssi_min_file_chunk"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
      ngx_conf_set_size_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_ssi_loc_conf_t, min_file_chunk),
      NULL },

    { ngx_string("ssi_value_length"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
      ngx_conf_set_size_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_ssi_loc_conf_t, value_len),
      NULL },

    { ngx_string("ssi_types"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
      ngx_http_ssi_types,
      NGX_HTTP_LOC_CONF_OFFSET,
      0,
      NULL },

      ngx_null_command
};



static ngx_http_module_t  ngx_http_ssi_filter_module_ctx = {
    ngx_http_ssi_preconfiguration,         /* preconfiguration */
    ngx_http_ssi_filter_init,              /* postconfiguration */

    ngx_http_ssi_create_main_conf,         /* create main configuration */
    ngx_http_ssi_init_main_conf,           /* init main configuration */

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

    ngx_http_ssi_create_loc_conf,          /* create location configuration */
    ngx_http_ssi_merge_loc_conf            /* merge location configuration */
};


ngx_module_t  ngx_http_ssi_filter_module = {
    NGX_MODULE_V1,
    &ngx_http_ssi_filter_module_ctx,       /* module context */
    ngx_http_ssi_filter_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 ngx_http_output_header_filter_pt  ngx_http_next_header_filter;
static ngx_http_output_body_filter_pt    ngx_http_next_body_filter;


static u_char ngx_http_ssi_string[] = "<!--";

static ngx_str_t ngx_http_ssi_none = ngx_string("(none)");
static ngx_str_t ngx_http_ssi_null_string = ngx_null_string;


#define  NGX_HTTP_SSI_INCLUDE_VIRTUAL  0
#define  NGX_HTTP_SSI_INCLUDE_FILE     1
#define  NGX_HTTP_SSI_INCLUDE_WAIT     2
#define  NGX_HTTP_SSI_INCLUDE_SET      3
#define  NGX_HTTP_SSI_INCLUDE_STUB     4

#define  NGX_HTTP_SSI_ECHO_VAR         0
#define  NGX_HTTP_SSI_ECHO_DEFAULT     1
#define  NGX_HTTP_SSI_ECHO_ENCODING    2

#define  NGX_HTTP_SSI_CONFIG_ERRMSG    0
#define  NGX_HTTP_SSI_CONFIG_TIMEFMT   1

#define  NGX_HTTP_SSI_SET_VAR          0
#define  NGX_HTTP_SSI_SET_VALUE        1

#define  NGX_HTTP_SSI_IF_EXPR          0

#define  NGX_HTTP_SSI_BLOCK_NAME       0


static ngx_http_ssi_param_t  ngx_http_ssi_include_params[] = {
    { ngx_string("virtual"), NGX_HTTP_SSI_INCLUDE_VIRTUAL, 0, 0 },
    { ngx_string("file"), NGX_HTTP_SSI_INCLUDE_FILE, 0, 0 },
    { ngx_string("wait"), NGX_HTTP_SSI_INCLUDE_WAIT, 0, 0 },
    { ngx_string("set"), NGX_HTTP_SSI_INCLUDE_SET, 0, 0 },
    { ngx_string("stub"), NGX_HTTP_SSI_INCLUDE_STUB, 0, 0 },
    { ngx_null_string, 0, 0, 0 }
};


static ngx_http_ssi_param_t  ngx_http_ssi_echo_params[] = {
    { ngx_string("var"), NGX_HTTP_SSI_ECHO_VAR, 1, 0 },
    { ngx_string("default"), NGX_HTTP_SSI_ECHO_DEFAULT, 0, 0 },
    { ngx_string("encoding"), NGX_HTTP_SSI_ECHO_ENCODING, 0, 0 },
    { ngx_null_string, 0, 0, 0 }
};


static ngx_http_ssi_param_t  ngx_http_ssi_config_params[] = {
    { ngx_string("errmsg"), NGX_HTTP_SSI_CONFIG_ERRMSG, 0, 0 },
    { ngx_string("timefmt"), NGX_HTTP_SSI_CONFIG_TIMEFMT, 0, 0 },
    { ngx_null_string, 0, 0, 0 }
};


static ngx_http_ssi_param_t  ngx_http_ssi_set_params[] = {
    { ngx_string("var"), NGX_HTTP_SSI_SET_VAR, 1, 0 },
    { ngx_string("value"), NGX_HTTP_SSI_SET_VALUE, 1, 0 },
    { ngx_null_string, 0, 0, 0 }
};


static ngx_http_ssi_param_t  ngx_http_ssi_if_params[] = {
    { ngx_string("expr"), NGX_HTTP_SSI_IF_EXPR, 1, 0 },
    { ngx_null_string, 0, 0, 0 }
};


static ngx_http_ssi_param_t  ngx_http_ssi_block_params[] = {
    { ngx_string("name"), NGX_HTTP_SSI_BLOCK_NAME, 1, 0 },
    { ngx_null_string, 0, 0, 0 }
};


static ngx_http_ssi_param_t  ngx_http_ssi_no_params[] = {
    { ngx_null_string, 0, 0, 0 }
};


static ngx_http_ssi_command_t  ngx_http_ssi_commands[] = {
    { ngx_string("include"), ngx_http_ssi_include,
                       ngx_http_ssi_include_params, 0, 0, 1 },
    { ngx_string("echo"), ngx_http_ssi_echo,
                       ngx_http_ssi_echo_params, 0, 0, 0 },
    { ngx_string("config"), ngx_http_ssi_config,
                       ngx_http_ssi_config_params, 0, 0, 0 },
    { ngx_string("set"), ngx_http_ssi_set, ngx_http_ssi_set_params, 0, 0, 0 },

    { ngx_string("if"), ngx_http_ssi_if, ngx_http_ssi_if_params, 0, 0, 0 },
    { ngx_string("elif"), ngx_http_ssi_if, ngx_http_ssi_if_params,
                       NGX_HTTP_SSI_COND_IF, 0, 0 },
    { ngx_string("else"), ngx_http_ssi_else, ngx_http_ssi_no_params,
                       NGX_HTTP_SSI_COND_IF, 0, 0 },
    { ngx_string("endif"), ngx_http_ssi_endif, ngx_http_ssi_no_params,
                       NGX_HTTP_SSI_COND_ELSE, 0, 0 },

    { ngx_string("block"), ngx_http_ssi_block,
                       ngx_http_ssi_block_params, 0, 0, 0 },
    { ngx_string("endblock"), ngx_http_ssi_endblock,
                       ngx_http_ssi_no_params, 0, 1, 0 },

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


static ngx_http_variable_t  ngx_http_ssi_vars[] = {

    { ngx_string("date_local"), NULL, ngx_http_ssi_date_gmt_local_variable, 0,
      NGX_HTTP_VAR_NOCACHEABLE, 0 },

    { ngx_string("date_gmt"), NULL, ngx_http_ssi_date_gmt_local_variable, 1,
      NGX_HTTP_VAR_NOCACHEABLE, 0 },

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



static ngx_int_t
ngx_http_ssi_header_filter(ngx_http_request_t *r)
{
    ngx_uint_t                i;
    ngx_str_t                *type;
    ngx_http_ssi_ctx_t       *ctx;
    ngx_http_ssi_loc_conf_t  *slcf;

    slcf = ngx_http_get_module_loc_conf(r, ngx_http_ssi_filter_module);

    if (!slcf->enable
        || r->headers_out.content_type.len == 0
        || r->headers_out.content_length_n == 0)
    {
        return ngx_http_next_header_filter(r);
    }


    type = slcf->types->elts;
    for (i = 0; i < slcf->types->nelts; i++) {
        if (r->headers_out.content_type.len >= type[i].len
            && ngx_strncasecmp(r->headers_out.content_type.data,
                               type[i].data, type[i].len) == 0)
        {
            goto found;
        }
    }

    return ngx_http_next_header_filter(r);


found:

    ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_ssi_ctx_t));
    if (ctx == NULL) {
        return NGX_ERROR;
    }

    ngx_http_set_ctx(r, ctx, ngx_http_ssi_filter_module);


    ctx->value_len = slcf->value_len;
    ctx->last_out = &ctx->out;

    ctx->encoding = NGX_HTTP_SSI_ENTITY_ENCODING;
    ctx->output = 1;

    ctx->params.elts = ctx->params_array;
    ctx->params.size = sizeof(ngx_table_elt_t);
    ctx->params.nalloc = NGX_HTTP_SSI_PARAMS_N;
    ctx->params.pool = r->pool;

    ctx->timefmt.len = sizeof("%A, %d-%b-%Y %H:%M:%S %Z") - 1;
    ctx->timefmt.data = (u_char *) "%A, %d-%b-%Y %H:%M:%S %Z";

    ctx->errmsg.len =
              sizeof("[an error occurred while processing the directive]") - 1;
    ctx->errmsg.data = (u_char *)
                     "[an error occurred while processing the directive]";

    r->filter_need_in_memory = 1;

    if (r == r->main) {
        ngx_http_clear_content_length(r);
        ngx_http_clear_last_modified(r);
    }

    return ngx_http_next_header_filter(r);
}


static ngx_int_t
ngx_http_ssi_body_filter(ngx_http_request_t *r, ngx_chain_t *in)
{
    size_t                     len;
    ngx_int_t                  rc;
    ngx_buf_t                 *b;
    ngx_uint_t                 i, index;
    ngx_chain_t               *cl, **ll;
    ngx_table_elt_t           *param;
    ngx_http_request_t        *pr;
    ngx_http_ssi_ctx_t        *ctx, *mctx;
    ngx_http_ssi_block_t      *bl;
    ngx_http_ssi_param_t      *prm;
    ngx_http_ssi_command_t    *cmd;
    ngx_http_ssi_loc_conf_t   *slcf;
    ngx_http_ssi_main_conf_t  *smcf;
    ngx_str_t                 *params[NGX_HTTP_SSI_MAX_PARAMS + 1];

    ctx = ngx_http_get_module_ctx(r, ngx_http_ssi_filter_module);

    if (ctx == NULL
        || (in == NULL
            && ctx->buf == NULL
            && ctx->in == NULL
            && ctx->busy == NULL))
    {
        return ngx_http_next_body_filter(r, in);
    }

    /* add the incoming chain to the chain ctx->in */

    if (in) {
        if (ngx_chain_add_copy(r->pool, &ctx->in, in) == NGX_ERROR) {
            return NGX_ERROR;
        }
    }

    if (ctx->wait) {
        if (r->connection->data != r) {
            ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                           "http ssi filter \"%V\" wait", &r->uri);
            return NGX_AGAIN;
        }

        for (pr = ctx->wait->parent; pr; pr = pr->parent) {
            if (pr == r) {
                ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                               "http ssi filter \"%V\" flush", &r->uri);

                rc = ngx_http_next_body_filter(r, NULL);

                if (ctx->wait->done) {
                    ctx->wait = NULL;
                }

                if (rc == NGX_ERROR || rc == NGX_AGAIN) {
                    return rc;
                }

                break;
            }
        }

        if (ctx->wait == r) {
            ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                           "http ssi filter \"%V\" continue", &r->uri);
            ctx->wait = NULL;
        }
    }

    slcf = ngx_http_get_module_loc_conf(r, ngx_http_ssi_filter_module);

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "http ssi filter \"%V\"", &r->uri);

    while (ctx->in || ctx->buf) {

        if (ctx->buf == NULL ){
            ctx->buf = ctx->in->buf;
            ctx->in = ctx->in->next;
            ctx->pos = ctx->buf->pos;
        }

        if (ctx->state == ssi_start_state) {