new file mode 100644
--- /dev/null
+++ b/src/http/modules/ngx_http_ssi_filter.c
@@ -0,0 +1,1179 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ */
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_http.h>
+
+#define NGX_HTTP_SSI_MAX_PARAMS   16
+
+#define NGX_HTTP_SSI_COMMAND_LEN  31
+#define NGX_HTTP_SSI_PARAM_LEN    31
+#define NGX_HTTP_SSI_PARAMS_N     4
+
+#define NGX_HTTP_SSI_ERROR        1
+
+
+typedef struct {
+    ngx_flag_t        enable;
+    ngx_flag_t        silent_errors;
+
+    size_t            min_file_chunk;
+    size_t            value_len;
+} ngx_http_ssi_conf_t;
+
+
+typedef struct {
+    ngx_buf_t         *buf;
+
+    u_char            *pos;
+    u_char            *copy_start;
+    u_char            *copy_end;
+
+    ngx_str_t          command;
+    ngx_array_t        params;
+    ngx_table_elt_t   *param;
+    ngx_table_elt_t    params_array[NGX_HTTP_SSI_PARAMS_N];
+
+    ngx_chain_t       *in;
+    ngx_chain_t       *out;
+    ngx_chain_t      **last_out;
+
+    ngx_uint_t         state;
+    ngx_uint_t         saved_state;
+    size_t             saved;
+    size_t             looked;
+
+    size_t             value_len;
+} ngx_http_ssi_ctx_t;
+
+
+typedef ngx_int_t (*ngx_http_ssi_command_pt) (ngx_http_request_t *r,
+    ngx_http_ssi_ctx_t *ctx, ngx_str_t **);
+
+
+typedef struct {
+    ngx_str_t                 name;
+    ngx_uint_t                index;
+
+    ngx_uint_t                mandatory;
+} ngx_http_ssi_param_t;
+
+
+typedef struct {
+    ngx_str_t                 name;
+    ngx_http_ssi_command_pt   handler;
+    ngx_http_ssi_param_t     *params;
+
+    ngx_uint_t                flush;    /* unsigned  flush:1; */
+} ngx_http_ssi_command_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_error(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_int_t ngx_http_ssi_echo(ngx_http_request_t *r,
+    ngx_http_ssi_ctx_t *ctx, ngx_str_t **params);
+
+static void *ngx_http_ssi_create_conf(ngx_conf_t *cf);
+static char *ngx_http_ssi_merge_conf(ngx_conf_t *cf,
+    void *parent, void *child);
+static ngx_int_t ngx_http_ssi_filter_init(ngx_cycle_t *cycle);
+
+
+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_CONF_FLAG,
+      ngx_conf_set_flag_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_ssi_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_conf_t, silent_errors),
+      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_conf_t, min_file_chunk),
+      NULL },
+
+      ngx_null_command
+};
+
+
+    
+static ngx_http_module_t  ngx_http_ssi_filter_module_ctx = {
+    NULL,                                  /* pre conf */
+
+    NULL,                                  /* create main configuration */
+    NULL,                                  /* init main configuration */
+
+    NULL,                                  /* create server configuration */
+    NULL,                                  /* merge server configuration */
+
+    ngx_http_ssi_create_conf,              /* create location configuration */
+    ngx_http_ssi_merge_conf                /* merge location configuration */
+};  
+
+
+ngx_module_t  ngx_http_ssi_filter_module = {
+    NGX_MODULE,
+    &ngx_http_ssi_filter_module_ctx,       /* module context */
+    ngx_http_ssi_filter_commands,          /* module directives */
+    NGX_HTTP_MODULE,                       /* module type */
+    ngx_http_ssi_filter_init,              /* init module */
+    NULL                                   /* init child */
+};
+
+
+static ngx_int_t (*ngx_http_next_header_filter) (ngx_http_request_t *r);
+static ngx_int_t (*ngx_http_next_body_filter) (ngx_http_request_t *r,
+    ngx_chain_t *in);
+
+
+static u_char ngx_http_ssi_string[] = "<!--";
+static u_char ngx_http_ssi_error_string[] =
+                          "[an error occurred while processing the directive]";
+
+static ngx_str_t ngx_http_ssi_none = ngx_string("(none)");
+
+
+#define  NGX_HTTP_SSI_ECHO_VAR      0
+#define  NGX_HTTP_SSI_ECHO_DEFAULT  1
+
+static ngx_http_ssi_param_t  ngx_http_ssi_echo_params[] = {
+    { ngx_string("var"), NGX_HTTP_SSI_ECHO_VAR, 1 },
+    { ngx_string("default"), NGX_HTTP_SSI_ECHO_DEFAULT, 0 },
+    { ngx_null_string, 0, 0 }
+};
+
+
+static ngx_http_ssi_command_t  ngx_http_ssi_commands[] = {
+    { ngx_string("echo"), ngx_http_ssi_echo, ngx_http_ssi_echo_params, 0 },
+    { ngx_null_string, NULL, NULL, 0 }
+};
+
+
+static ngx_int_t
+ngx_http_ssi_header_filter(ngx_http_request_t *r)
+{
+    ngx_http_ssi_ctx_t   *ctx;
+    ngx_http_ssi_conf_t  *conf;
+
+    conf = ngx_http_get_module_loc_conf(r, ngx_http_ssi_filter_module);
+
+    if (!conf->enable) {
+        return ngx_http_next_header_filter(r);
+    }
+
+    /* TODO: "text/html" -> custom types */
+
+    if (r->headers_out.content_type
+        && ngx_strncasecmp(r->headers_out.content_type->value.data,
+                                                          "text/html", 5) != 0)
+    {
+        return ngx_http_next_header_filter(r);
+    }
+
+
+    if (!(ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_ssi_ctx_t)))) {
+        return NGX_ERROR;
+    }
+
+    ngx_http_set_ctx(r, ctx, ngx_http_ssi_filter_module);
+
+
+    ctx->value_len = conf->value_len;
+    ctx->last_out = &ctx->out;
+
+    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;
+
+    r->headers_out.content_length_n = -1;
+    if (r->headers_out.content_length) {
+        r->headers_out.content_length->key.len = 0;
+        r->headers_out.content_length = NULL;
+    }
+
+    r->headers_out.last_modified_time = -1;
+    if (r->headers_out.last_modified) {
+        r->headers_out.last_modified->key.len = 0;
+        r->headers_out.last_modified = NULL;
+    }
+
+    r->filter_need_in_memory = 1;
+    r->filter_ssi_need_in_memory = 1;
+
+    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)
+{
+    ngx_int_t                rc;
+    ngx_uint_t               i;
+    ngx_buf_t               *b;
+    ngx_chain_t             *cl;
+    ngx_table_elt_t         *param;
+    ngx_http_ssi_ctx_t      *ctx;
+    ngx_http_ssi_conf_t     *conf;
+    ngx_http_ssi_param_t    *prm;
+    ngx_http_ssi_command_t  *cmd;
+    ngx_str_t               *params[NGX_HTTP_SSI_MAX_PARAMS];
+
+    ctx = ngx_http_get_module_ctx(r, ngx_http_ssi_filter_module);
+
+    if (ctx == NULL || (in == NULL && ctx->in == 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;
+        }
+    }
+
+    conf = ngx_http_get_module_loc_conf(r, ngx_http_ssi_filter_module);
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                   "http ssi filter");
+
+    b = NULL;
+
+    while (ctx->in) {
+
+        ctx->buf = ctx->in->buf;
+        ctx->in = ctx->in->next;
+        ctx->pos = ctx->buf->pos;
+
+        if (ctx->state == ssi_start_state) {
+            ctx->copy_start = ctx->pos;
+            ctx->copy_end = ctx->pos;
+        }
+
+        while (ctx->pos < ctx->buf->last) {
+
+            ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                           "saved: %d state: %d", ctx->saved, ctx->state);
+
+            rc = ngx_http_ssi_parse(r, ctx);
+
+            ngx_log_debug4(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                           "parse: %d, looked: %d %p-%p",
+                           rc, ctx->looked, ctx->copy_start, ctx->copy_end);
+
+            if (rc == NGX_ERROR) {
+                return rc;
+            }
+
+            if (ctx->copy_start != ctx->copy_end) {
+
+                ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                               "saved: %d", ctx->saved);
+
+                if (ctx->saved) {
+                    if (!(b = ngx_calloc_buf(r->pool))) {
+                        return NGX_ERROR;
+                    }
+
+                    b->memory = 1;
+                    b->pos = ngx_http_ssi_string;
+                    b->last = ngx_http_ssi_string + ctx->saved;
+
+                    if (!(cl = ngx_alloc_chain_link(r->pool))) {
+                        return NGX_ERROR;
+                    }
+
+                    cl->buf = b;
+                    *ctx->last_out = cl;
+                    ctx->last_out = &cl->next;
+
+                    ctx->saved = 0;
+                }
+
+                if (!(b = ngx_calloc_buf(r->pool))) {
+                    return NGX_ERROR;
+                }
+
+                ngx_memcpy(b, ctx->buf, sizeof(ngx_buf_t));
+
+                b->last_buf = 0;
+                b->pos = ctx->copy_start;
+                b->last = ctx->copy_end;
+
+                if (b->in_file) {
+
+                    if (conf->min_file_chunk < (size_t) (b->last - b->pos)) {
+                        b->file_last = b->file_pos + (b->last - b->start);
+                        b->file_pos += b->pos - b->start;
+
+                    } else {
+                        b->in_file = 0;
+                    }
+                }
+
+                if (!(cl = ngx_alloc_chain_link(r->pool))) {
+                    return NGX_ERROR;
+                }
+
+                cl->buf = b;
+                cl->next = NULL;
+                *ctx->last_out = cl;
+                ctx->last_out = &cl->next;
+            }
+
+            if (ctx->state == ssi_start_state) {
+                ctx->copy_start = ctx->pos;
+                ctx->copy_end = ctx->pos;
+
+            } else {
+                ctx->copy_start = NULL;
+                ctx->copy_end = NULL;
+            }
+
+            if (rc == NGX_AGAIN) {
+                continue;
+            }
+
+
+            if (rc == NGX_OK) {
+
+                for (cmd = ngx_http_ssi_commands; cmd->handler; cmd++) {
+                    if (cmd->name.len == 0) {
+                        cmd = (ngx_http_ssi_command_t *) cmd->handler;
+                    }
+
+                    if (cmd->name.len != ctx->command.len
+                        || ngx_strncmp(cmd->name.data, ctx->command.data,
+                                       ctx->command.len) != 0)
+                    {
+                        continue;
+                    }
+
+                    break;
+                }
+
+                if (cmd->name.len == 0) {
+                    ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                                  "invalid SSI command: \"%V\"", &ctx->command);
+                    goto ssi_error;
+                }
+
+                ngx_memzero(params,
+                            NGX_HTTP_SSI_MAX_PARAMS * sizeof(ngx_str_t *));
+
+                param = ctx->params.elts;
+
+
+                for (i = 0; i < ctx->params.nelts; i++) {
+
+                    for (prm = cmd->params; prm->name.len; prm++) {
+
+                        if (param[i].key.len != prm->name.len
+                            || ngx_strncmp(param[i].key.data, prm->name.data,
+                                           prm->name.len) != 0)
+                        {
+                            continue;
+                        }
+
+                        if (params[prm->index]) {
+                            ngx_log_error(NGX_LOG_ERR,
+                                          r->connection->log, 0,
+                                          "duplicate \"%V\" parameter "
+                                          "in \"%V\" SSI command",
+                                          &param[i].key, &ctx->command);
+
+                            goto ssi_error;
+                        }
+
+                        params[prm->index] = &param[i].value;
+
+                        break;
+                    }
+
+                    if (prm->name.len == 0) {
+                        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                                      "invalid parameter name: \"%V\" "
+                                      "in \"%V\" SSI command",
+                                      &param[i].key, &ctx->command);
+
+                        goto ssi_error;
+                    }
+                }
+
+                for (prm = cmd->params; prm->name.len; prm++) {
+                    if (prm->mandatory && params[prm->index] == 0) {
+                        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                                      "mandatory \"%V\" parameter is absent "
+                                      "in \"%V\" SSI command",
+                                      &prm->name, &ctx->command);
+
+                        goto ssi_error;
+                    }
+                }
+
+                if (cmd->handler(r, ctx, params) == NGX_OK) {
+                    continue;
+                }
+            }
+
+
+            /* rc == NGX_HTTP_SSI_ERROR */
+
+ssi_error:
+
+            if (conf->silent_errors) {
+                continue;
+            }
+
+            if (!(b = ngx_calloc_buf(r->pool))) {
+                return NGX_ERROR;
+            }
+
+            b->memory = 1;
+            b->pos = ngx_http_ssi_error_string;
+            b->last = ngx_http_ssi_error_string
+                      + sizeof(ngx_http_ssi_error_string) - 1;
+
+            if (!(cl = ngx_alloc_chain_link(r->pool))) {
+                return NGX_ERROR;
+            }
+
+            cl->buf = b;
+            cl->next = NULL;
+            *ctx->last_out = cl;
+            ctx->last_out = &cl->next;
+
+            continue;
+        }
+
+        ctx->buf->pos = ctx->buf->last;
+
+        if (b && ctx->buf->last_buf) {
+            b->last_buf = 1;
+        }
+
+        ctx->saved = ctx->looked;
+    }
+
+    if (ctx->out == NULL) {
+        return NGX_OK;
+    }
+
+    rc = ngx_http_next_body_filter(r, ctx->out);
+
+    ctx->out = NULL;
+    ctx->last_out = &ctx->out;
+
+    return rc;
+}
+
+
+static ngx_int_t
+ngx_http_ssi_parse(ngx_http_request_t *r, ngx_http_ssi_ctx_t *ctx)
+{
+    u_char                *p, *last, *copy_end, ch;
+    size_t                 looked;
+    ngx_http_ssi_state_e   state;
+
+    state = ctx->state;
+    looked = ctx->looked;
+    last = ctx->buf->last;
+    copy_end = ctx->copy_end;
+
+    for (p = ctx->pos; p < last; p++) {
+
+        ch = *p;
+
+        if (state == ssi_start_state) {
+
+            /* the tight loop */
+
+            for ( /* void */ ; p < last; ch = *(++p)) {
+                if (ch != '<') {
+                    continue;
+                }
+
+                copy_end = p;
+                looked = 1;
+                state = ssi_tag_state;
+
+                goto tag_started;
+            }
+
+            ctx->pos = p;
+            ctx->looked = looked;
+            ctx->copy_end = p;
+
+            if (ctx->copy_start == NULL) {
+                ctx->copy_start = ctx->buf->pos;
+            }
+
+            return NGX_AGAIN;
+
+tag_started:
+            continue;
+        }
+
+        switch (state) {
+
+        case ssi_start_state:
+            break;
+
+        case ssi_tag_state:
+            switch (ch) {
+            case '!':
+                looked = 2;
+                state = ssi_comment0_state;
+                break;
+
+            case '<':
+                copy_end = p;
+                break;
+
+            default:
+                copy_end = p;
+                looked = 0;
+                state = ssi_start_state;
+                break;
+            }
+
+            break;
+
+        case ssi_comment0_state:
+            switch (ch) {
+            case '-':
+                looked = 3;
+                state = ssi_comment1_state;
+                break;
+
+            case '<':
+                copy_end = p;
+                looked = 1;
+                state = ssi_tag_state;
+                break;
+
+            default:
+                copy_end = p;
+                looked = 0;
+                state = ssi_start_state;
+                break;
+            }
+
+            break;
+
+        case ssi_comment1_state:
+            switch (ch) {
+            case '-':
+                looked = 4;
+                state = ssi_sharp_state;
+                break;
+
+            case '<':
+                copy_end = p;
+                looked = 1;
+                state = ssi_tag_state;
+                break;
+
+            default:
+                copy_end = p;
+                looked = 0;
+                state = ssi_start_state;
+                break;
+            }
+
+            break;
+
+        case ssi_sharp_state:
+            switch (ch) {
+            case '#':
+                if (ctx->copy_start) {
+                    ctx->saved = 0;
+                }
+                looked = 0;
+                state = ssi_precommand_state;
+                break;
+
+            case '<':
+                copy_end = p;
+                looked = 1;
+                state = ssi_tag_state;
+                break;
+
+            default:
+                copy_end = p;
+                looked = 0;
+                state = ssi_start_state;
+                break;
+            }
+
+            break;
+
+        case ssi_precommand_state:
+            switch (ch) {
+            case ' ':
+            case CR:
+            case LF:
+            case '\t':
+                break;
+
+            default:
+                ctx->command.len = 1;
+                ctx->command.data = ngx_palloc(r->pool,
+                                               NGX_HTTP_SSI_COMMAND_LEN + 1);
+                if (ctx->command.data == NULL) {
+                    return NGX_ERROR;
+                }
+
+                ctx->command.data[0] = ch;
+                ctx->params.nelts = 0;
+                state = ssi_command_state;
+                break;
+            }
+
+            break;
+
+        case ssi_command_state:
+            switch (ch) {
+            case ' ':
+            case CR:
+            case LF:
+            case '\t':
+                state = ssi_preparam_state;
+                break;
+
+            case '-':
+                state = ssi_comment_end0_state;
+                break;
+
+            default:
+                ctx->command.data[ctx->command.len++] = ch;
+
+                if (ctx->command.len == NGX_HTTP_SSI_COMMAND_LEN) {
+                    ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                                  "the \"%V\" SSI command is too long",
+                                  &ctx->command);
+
+                    state = ssi_error_state;
+                    break;
+                }
+            }
+
+            break;
+
+        case ssi_preparam_state:
+            switch (ch) {
+            case ' ':
+            case CR:
+            case LF:
+            case '\t':
+                break;
+
+            case '-':
+                state = ssi_comment_end0_state;
+                break;
+
+            default:
+                if (!(ctx->param = ngx_array_push(&ctx->params))) {
+                    return NGX_ERROR;
+                }
+
+                ctx->param->key.len = 1;
+                ctx->param->key.data = ngx_palloc(r->pool,
+                                                  NGX_HTTP_SSI_PARAM_LEN + 1);
+                if (ctx->param->key.data == NULL) {
+                    return NGX_ERROR;
+                }
+
+                ctx->param->key.data[0] = ch;
+
+                ctx->param->value.len = 0;
+                ctx->param->value.data = ngx_palloc(r->pool,
+                                                    ctx->value_len + 1);
+                if (ctx->param->value.data == NULL) {
+                    return NGX_ERROR;
+                }
+
+                state = ssi_param_state;
+                break;
+            }
+
+            break;
+
+        case ssi_param_state:
+            switch (ch) {
+            case ' ':
+            case CR:
+            case LF:
+            case '\t':
+                state = ssi_preequal_state;
+                break;
+
+            case '=':
+                state = ssi_prevalue_state;
+                break;
+
+            case '-':
+                state = ssi_error_end0_state;
+
+                ctx->param->key.data[ctx->param->key.len++] = ch;
+                ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                              "invalid \"%V\" parameter in \"%V\" SSI command",
+                              &ctx->param->key, &ctx->command);
+                break;
+
+            default:
+                ctx->param->key.data[ctx->param->key.len++] = ch;
+
+                if (ctx->param->key.len == NGX_HTTP_SSI_PARAM_LEN) {
+                    state = ssi_error_state;
+                    ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                                  "too long \"%V\" parameter in "
+                                  "\"%V\" SSI command",
+                                  &ctx->param->key, &ctx->command);
+                    break;
+                }
+            }
+
+            break;
+
+        case ssi_preequal_state:
+            switch (ch) {
+            case ' ':
+            case CR:
+            case LF:
+            case '\t':
+                break;
+
+            case '=':
+                state = ssi_prevalue_state;
+                break;
+
+            default:
+                if (ch == '-') {
+                    state = ssi_error_end0_state;
+                } else {
+                    state = ssi_error_state;
+                }
+
+                ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                              "unexpected \"%c\" symbol after \"%V\" "
+                              "parameter in \"%V\" SSI command",
+                              ch, &ctx->param->key, &ctx->command);
+                break;
+            }
+
+            break;
+
+        case ssi_prevalue_state:
+            switch (ch) {
+            case ' ':
+            case CR:
+            case LF:
+            case '\t':
+                break;
+
+            case '"':
+                state = ssi_double_quoted_value_state;
+                break;
+
+            case '\'':
+                state = ssi_quoted_value_state;
+                break;
+
+            default:
+                if (ch == '-') {
+                    state = ssi_error_end0_state;
+                } else {
+                    state = ssi_error_state;
+                }
+
+                ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                              "unexpected \"%c\" symbol before value of "
+                              "\"%V\" parameter in \"%V\" SSI command",
+                              ch, &ctx->param->key, &ctx->command);
+                break;
+            }
+
+            break;
+
+        case ssi_double_quoted_value_state:
+            switch (ch) {
+            case '\\':
+                ctx->saved_state = ssi_double_quoted_value_state;
+                state = ssi_quoted_symbol_state;
+                break;
+
+            case '"':
+                state = ssi_postparam_state;
+                break;
+
+            default:
+                ctx->param->value.data[ctx->param->value.len++] = ch;
+
+                if (ctx->param->value.len == ctx->value_len) {
+                    ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                                  "too long \"%V\" value of \"%V\" parameter "
+                                  "in \"%V\" SSI command",
+                                  &ctx->param->value, &ctx->param->key,
+                                  &ctx->command);
+                    state = ssi_error_state;
+                    break;
+                }
+            }
+
+            break;
+
+        case ssi_quoted_value_state:
+            switch (ch) {
+            case '\\':
+                ctx->saved_state = ssi_quoted_value_state;
+                state = ssi_quoted_symbol_state;
+                break;
+
+            case '\'':
+                state = ssi_postparam_state;
+                break;
+
+            default:
+                ctx->param->value.data[ctx->param->value.len++] = ch;
+
+                if (ctx->param->value.len == ctx->value_len) {
+                    ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                                  "too long \"%V\" value of \"%V\" parameter "
+                                  "in \"%V\" SSI command",
+                                  &ctx->param->value, &ctx->param->key,
+                                  &ctx->command);
+                    state = ssi_error_state;
+                    break;
+                }
+            }
+
+            break;
+
+        case ssi_quoted_symbol_state:
+            ctx->param->value.data[ctx->param->value.len++] = ch;
+
+            if (ctx->param->value.len == ctx->value_len) {
+                if (ctx->param->value.len == ctx->value_len) {
+                    ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                                  "too long \"%V\" value of \"%V\" parameter "
+                                  "in \"%V\" SSI command",
+                                  &ctx->param->value, &ctx->param->key,
+                                  &ctx->command);
+                    state = ssi_error_state;
+                    break;
+                }
+            }
+
+            state = ctx->saved_state;
+            break;
+
+        case ssi_postparam_state:
+            switch (ch) {
+            case ' ':
+            case CR:
+            case LF:
+            case '\t':
+                state = ssi_preparam_state;
+                break;
+
+            case '-':
+                state = ssi_comment_end0_state;
+                break;
+
+            default:
+                ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                              "unexpected \"%c\" symbol after \"%V\" value "
+                              "of \"%V\" parameter in \"%V\" SSI command",
+                              ch, &ctx->param->value, &ctx->param->key,
+                              &ctx->command);
+                state = ssi_error_state;
+                break;
+            }
+
+            break;
+
+        case ssi_comment_end0_state:
+            switch (ch) {
+            case '-':
+                state = ssi_comment_end1_state;
+                break;
+
+            default:
+                ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                              "unexpected \"%c\" symbol in \"%V\" SSI command",
+                              ch, &ctx->command);
+                state = ssi_error_state;
+                break;
+            }
+
+            break;
+
+        case ssi_comment_end1_state:
+            switch (ch) {
+            case '>':
+                ctx->state = ssi_start_state;
+                ctx->pos = p + 1;
+                ctx->looked = looked;
+                ctx->copy_end = copy_end;
+
+                if (ctx->copy_start == NULL && copy_end) {
+                    ctx->copy_start = ctx->buf->pos;
+                }
+
+                return NGX_OK;
+
+            default:
+                ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                              "unexpected \"%c\" symbol in \"%V\" SSI command",
+                              ch, &ctx->command);
+                state = ssi_error_state;
+                break;
+            }
+
+            break;
+
+        case ssi_error_state:
+            switch (ch) {
+            case '-':
+                state = ssi_error_end0_state;
+                break;
+
+            default:
+                break;
+            }
+
+            break;
+
+        case ssi_error_end0_state:
+            switch (ch) {
+            case '-':
+                state = ssi_error_end1_state;
+                break;
+
+            default:
+                state = ssi_error_state;
+                break;
+            }
+
+            break;
+
+        case ssi_error_end1_state:
+            switch (ch) {
+            case '>':
+                ctx->state = ssi_start_state;
+                ctx->pos = p + 1;
+                ctx->looked = looked;
+                ctx->copy_end = copy_end;
+
+                if (ctx->copy_start == NULL && copy_end) {
+                    ctx->copy_start = ctx->buf->pos;
+                }
+
+                return NGX_HTTP_SSI_ERROR;
+
+            default:
+                state = ssi_error_state;
+                break;
+            }
+
+            break;
+        }
+    }
+
+    ctx->state = state;
+    ctx->pos = p;
+    ctx->looked = looked;
+
+    ctx->copy_end = (state == ssi_start_state) ? p : copy_end;
+
+    if (ctx->copy_start == NULL && ctx->copy_end) {
+        ctx->copy_start = ctx->buf->pos;
+    }
+
+    return NGX_AGAIN;
+}
+
+
+static ngx_int_t
+ngx_http_ssi_echo(ngx_http_request_t *r, ngx_http_ssi_ctx_t *ctx,
+    ngx_str_t **params)
+{
+    u_char            ch;
+    ngx_uint_t        i, n;
+    ngx_buf_t        *b;
+    ngx_str_t        *var, *value;
+    ngx_chain_t      *cl;
+    ngx_list_part_t  *part;
+    ngx_table_elt_t  *header;
+
+    var = params[NGX_HTTP_SSI_ECHO_VAR];
+    value = NULL;
+
+    if (var->len > 5 && ngx_strncmp(var->data, "HTTP_", 5) == 0) {
+
+        part = &r->headers_in.headers.part;
+        header = part->elts;
+
+        for (i = 0; /* void */ ; i++) {
+
+            if (i >= part->nelts) {
+                if (part->next == NULL) {
+                    break;
+                }
+
+                part = part->next;
+                header = part->elts;
+                i = 0; 
+            }
+
+            for (n = 0; n + 5 < var->len && n < header[i].key.len; n++)
+            {
+                ch = header[i].key.data[n];
+
+                if (ch >= 'a' && ch <= 'z') {
+                    ch &= ~0x20;
+
+                } else if (ch == '-') {
+                    ch = '_';
+                }
+
+                if (var->data[n + 5] != ch) {
+                    break;
+                }
+            }
+
+            if (n + 5 == var->len) {
+                value = &header[i].value;
+                break;
+            }
+        }
+
+    } else if (var->len == sizeof("REMOTE_ADDR") - 1
+               && ngx_strncmp(var->data, "REMOTE_ADDR",
+                              sizeof("REMOTE_ADDR") - 1) == 0)
+    {
+        value = &r->connection->addr_text;
+    }
+
+
+    if (value == NULL) {
+        value = params[NGX_HTTP_SSI_ECHO_DEFAULT];
+    }
+
+    if (value == NULL) {
+        value = &ngx_http_ssi_none;
+
+    } else if (value->len == 0) {
+        return NGX_OK;
+    }
+
+    if (!(b = ngx_calloc_buf(r->pool))) {
+        return NGX_HTTP_SSI_ERROR;
+    }
+
+    if (!(cl = ngx_alloc_chain_link(r->pool))) {
+        return NGX_HTTP_SSI_ERROR;
+    }
+
+    b->memory = 1;
+    b->pos = value->data;
+    b->last = value->data + value->len;
+
+    cl->buf = b;
+    cl->next = NULL;
+    *ctx->last_out = cl;
+    ctx->last_out = &cl->next;
+
+    return NGX_OK;
+}
+
+
+static void *
+ngx_http_ssi_create_conf(ngx_conf_t *cf)
+{
+    ngx_http_ssi_conf_t  *conf;
+
+    if (!(conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_ssi_conf_t)))) {
+        return NGX_CONF_ERROR;
+    }
+
+    conf->enable = NGX_CONF_UNSET;
+    conf->silent_errors = NGX_CONF_UNSET;
+
+    conf->min_file_chunk = NGX_CONF_UNSET_SIZE;
+    conf->value_len = NGX_CONF_UNSET_SIZE;
+
+    return conf;
+}
+
+
+static char *
+ngx_http_ssi_merge_conf(ngx_conf_t *cf, void *parent, void *child)
+{
+    ngx_http_ssi_conf_t *prev = parent;
+    ngx_http_ssi_conf_t *conf = child;
+
+    ngx_conf_merge_value(conf->enable, prev->enable, 0);
+    ngx_conf_merge_value(conf->silent_errors, prev->silent_errors, 0);
+
+    ngx_conf_merge_size_value(conf->min_file_chunk, prev->min_file_chunk, 1024);
+    ngx_conf_merge_size_value(conf->value_len, prev->value_len, 256);
+
+    return NGX_CONF_OK;
+}
+
+
+static ngx_int_t
+ngx_http_ssi_filter_init(ngx_cycle_t *cycle)
+{
+    ngx_http_next_header_filter = ngx_http_top_header_filter;
+    ngx_http_top_header_filter = ngx_http_ssi_header_filter;
+
+    ngx_http_next_body_filter = ngx_http_top_body_filter;
+    ngx_http_top_body_filter = ngx_http_ssi_body_filter;
+
+    return NGX_OK;
+}