ngx_http_ssi_filter_module.c

Nginx是一个高性能的HTTP和反向代理服务器

        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                      "inlcusion may be either virtual=\"%V\" or file=\"%V\"",
                      uri, file);
        return NGX_HTTP_SSI_ERROR;
    }

    if (uri == NULL && file == NULL) {
        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                      "no parameter in \"include\" SSI command");
        return NGX_HTTP_SSI_ERROR;
    }

    if (set && stub) {
        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                      "\"set\" and \"stub\" may not be used together "
                      "in \"include\" SSI command");
        return NGX_HTTP_SSI_ERROR;
    }

    if (wait) {
        if (uri == NULL) {
            ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                          "\"wait\" may not be used with file=\"%V\"", file);
            return NGX_HTTP_SSI_ERROR;
        }

        if (wait->len == 2
            && ngx_strncasecmp(wait->data, (u_char *) "no", 2) == 0)
        {
            wait = NULL;

        } else if (wait->len != 3
                   || ngx_strncasecmp(wait->data, (u_char *) "yes", 3) != 0)
        {
            ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                          "invalid value \"%V\" in the \"wait\" parameter",
                          wait);
            return NGX_HTTP_SSI_ERROR;
        }
    }

    if (uri == NULL) {
        uri = file;
    }

    rc = ngx_http_ssi_evaluate_string(r, ctx, uri, NGX_HTTP_SSI_ADD_PREFIX);

    if (rc != NGX_OK) {
        return rc;
    }

    dst = uri->data;
    src = uri->data;

    ngx_unescape_uri(&dst, &src, uri->len, NGX_UNESCAPE_URI);

    len = (uri->data + uri->len) - src;
    if (len) {
        dst = ngx_copy(dst, src, len);
    }

    uri->len = dst - uri->data;

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "ssi include: \"%V\"", uri);

    args.len = 0;
    args.data = NULL;
    flags = 0;

    if (ngx_http_parse_unsafe_uri(r, uri, &args, &flags) != NGX_OK) {
        return NGX_HTTP_SSI_ERROR;
    }

    psr = NULL;

    mctx = ngx_http_get_module_ctx(r->main, ngx_http_ssi_filter_module);

    if (stub) {
        if (mctx->blocks) {
            bl = mctx->blocks->elts;
            for (i = 0; i < mctx->blocks->nelts; i++) {
                if (stub->len == bl[i].name.len
                    && ngx_strncmp(stub->data, bl[i].name.data, stub->len) == 0)
                {
                    goto found;
                }
            }
        }

        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                      "\"stub\"=\"%V\" for \"include\" not found", stub);
        return NGX_HTTP_SSI_ERROR;

    found:

        psr = ngx_palloc(r->pool, sizeof(ngx_http_post_subrequest_t));
        if (psr == NULL) {
            return NGX_ERROR;
        }

        psr->handler = ngx_http_ssi_stub_output;

        if (bl[i].count++) {

            out = NULL;
            ll = &out;

            for (tl = bl[i].bufs; tl; tl = tl->next) {

                if (ctx->free) {
                    cl = ctx->free;
                    ctx->free = ctx->free->next;
                    b = cl->buf;

                } else {
                    b = ngx_alloc_buf(r->pool);
                    if (b == NULL) {
                        return NGX_ERROR;
                    }

                    cl = ngx_alloc_chain_link(r->pool);
                    if (cl == NULL) {
                        return NGX_ERROR;
                    }

                    cl->buf = b;
                }

                ngx_memcpy(b, tl->buf, sizeof(ngx_buf_t));

                b->pos = b->start;

                *ll = cl;
                cl->next = NULL;
                ll = &cl->next;
            }

            psr->data = out;

        } else {
            psr->data = bl[i].bufs;
        }
    }

    if (set) {
        key = 0;

        for (i = 0; i < set->len; i++) {
            set->data[i] = ngx_tolower(set->data[i]);
            key = ngx_hash(key, set->data[i]);
        }

        psr = ngx_palloc(r->pool, sizeof(ngx_http_post_subrequest_t));
        if (psr == NULL) {
            return NGX_ERROR;
        }

        psr->handler = ngx_http_ssi_set_variable;
        psr->data = ngx_http_ssi_get_variable(r, set, key);

        if (psr->data == NULL) {

            if (mctx->variables == NULL) {
                mctx->variables = ngx_list_create(r->pool, 4,
                                                  sizeof(ngx_http_ssi_var_t));
                if (mctx->variables == NULL) {
                    return NGX_ERROR;
                }
            }

            var = ngx_list_push(mctx->variables);
            if (var == NULL) {
                return NGX_ERROR;
            }

            var->name = *set;
            var->key = key;
            var->value = ngx_http_ssi_null_string;
            psr->data = &var->value;
        }

        flags |= NGX_HTTP_SUBREQUEST_IN_MEMORY;
    }

    rc = ngx_http_subrequest(r, uri, &args, &sr, psr, flags);

    if (rc == NGX_DONE) {
        return NGX_DONE;
    }

    if (rc == NGX_ERROR) {
        return NGX_HTTP_SSI_ERROR;
    }

    if (wait == NULL && set == NULL) {
        return NGX_OK;
    }

    if (rc == NGX_AGAIN) {
        if (ctx->wait == NULL) {
            ctx->wait = sr;

        } else {
            ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                          "only one subrequest may be waited at the same time");
        }
    }

    return rc;
}


static ngx_int_t
ngx_http_ssi_stub_output(ngx_http_request_t *r, void *data, ngx_int_t rc)
{
    ngx_chain_t  *out;

    if (rc == NGX_ERROR || r->connection->error || r->request_output) {
        return rc;
    }

    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "ssi stub output: \"%V?%V\"", &r->uri, &r->args);

    out = data;

    if (!r->header_sent) {
        if (ngx_http_set_content_type(r) == NGX_ERROR) {
            return NGX_ERROR;
        }

        if (ngx_http_send_header(r) == NGX_ERROR) {
            return NGX_ERROR;
        }
    }

    return ngx_http_output_filter(r, out);
}


static ngx_int_t
ngx_http_ssi_set_variable(ngx_http_request_t *r, void *data, ngx_int_t rc)
{
    ngx_str_t  *value = data;

    if (r->upstream) {
        value->len = r->upstream->buffer.last - r->upstream->buffer.pos;
        value->data = r->upstream->buffer.pos;
    }

    return rc;
}


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                     *p;
    uintptr_t                   len;
    ngx_int_t                   key;
    ngx_uint_t                  i;
    ngx_buf_t                  *b;
    ngx_str_t                  *var, *value, *enc, text;
    ngx_chain_t                *cl;
    ngx_http_variable_value_t  *vv;

    var = params[NGX_HTTP_SSI_ECHO_VAR];

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "ssi echo \"%V\"", var);

    key = 0;

    for (i = 0; i < var->len; i++) {
        var->data[i] = ngx_tolower(var->data[i]);
        key = ngx_hash(key, var->data[i]);
    }

    value = ngx_http_ssi_get_variable(r, var, key);

    if (value == NULL) {
        vv = ngx_http_get_variable(r, var, key, 1);

        if (vv == NULL) {
            return NGX_HTTP_SSI_ERROR;
        }

        if (!vv->not_found) {
            text.data = vv->data;
            text.len = vv->len;
            value = &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;
        }

    } else {
        if (value->len == 0) {
            return NGX_OK;
        }
    }

    enc = params[NGX_HTTP_SSI_ECHO_ENCODING];

    if (enc) {
        if (enc->len == 4 && ngx_strncmp(enc->data, "none", 4) == 0) {

            ctx->encoding = NGX_HTTP_SSI_NO_ENCODING;

        } else if (enc->len == 3 && ngx_strncmp(enc->data, "url", 3) == 0) {

            ctx->encoding = NGX_HTTP_SSI_URL_ENCODING;

        } else if (enc->len == 6 && ngx_strncmp(enc->data, "entity", 6) == 0) {

            ctx->encoding = NGX_HTTP_SSI_ENTITY_ENCODING;

        } else {
            ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                          "unknown encoding \"%V\" in the \"echo\" command",
                          enc);
        }
    }

    switch (ctx->encoding) {

    case NGX_HTTP_SSI_NO_ENCODING:
        break;

    case NGX_HTTP_SSI_URL_ENCODING:
        len = 2 * ngx_escape_uri(NULL, value->data, value->len,
                                 NGX_ESCAPE_HTML);

        if (len) {
            p = ngx_palloc(r->pool, value->len + len);
            if (p == NULL) {
                return NGX_HTTP_SSI_ERROR;
            }

            (void) ngx_escape_uri(p, value->data, value->len, NGX_ESCAPE_HTML);

            value->len += len;
            value->data = p;
        }

        break;

    case NGX_HTTP_SSI_ENTITY_ENCODING:
        len = ngx_escape_html(NULL, value->data, value->len);

        if (len) {
            p = ngx_palloc(r->pool, value->len + len);
            if (p == NULL) {
                return NGX_HTTP_SSI_ERROR;
            }

            (void) ngx_escape_html(p, value->data, value->len);

            value->len += len;
            value->data = p;
        }

        break;
    }

    b = ngx_calloc_buf(r->pool);
    if (b == NULL) {
        return NGX_HTTP_SSI_ERROR;
    }

    cl = ngx_alloc_chain_link(r->pool);
    if (cl == NULL) {
        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 ngx_int_t
ngx_http_ssi_config(ngx_http_request_t *r, ngx_http_ssi_ctx_t *ctx,
    ngx_str_t **params)
{
    ngx_str_t  *value;

    value = params[NGX_HTTP_SSI_CONFIG_TIMEFMT];

    if (value) {
        ctx->timefmt.len = value->len;
        ctx->timefmt.data = ngx_palloc(r->pool, value->len + 1);
        if (ctx->timefmt.data == NULL) {
            return NGX_HTTP_SSI_ERROR;
        }

        ngx_cpystrn(ctx->timefmt.data, value->data, value->len + 1);
    }

    value = params[NGX_HTTP_SSI_CONFIG_ERRMSG];

    if (value) {
        ctx->errmsg = *value;
    }

    return NGX_OK;
}


static ngx_int_t
ngx_http_ssi_set(ngx_http_request_t *r, ngx_http_ssi_ctx_t *ctx,
    ngx_str_t **params)
{
    ngx_int_t            key, rc;
    ngx_uint_t           i;
    ngx_str_t           *name, *value, *vv;
    ngx_http_ssi_var_t  *var;
    ngx_http_ssi_ctx_t  *mctx;

    mctx = ngx_http_get_module_ctx(r->main, ngx_http_ssi_filter_module);

    if (mctx->variables == NULL) {
        mctx->variables = ngx_list_create(r->pool, 4,
                                          sizeof(ngx_http_ssi_var_t));
        if (mctx->variables == NULL) {
            return NGX_ERROR;
        }
    }

    name = params[NGX_HTTP_SSI_SET_VAR];
    value = params[NGX_HTTP_SSI_SET_VALUE];

    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "ssi set \"%V\" \"%V\"", name, value);

    rc = ngx_http_ssi_evaluate_string(r, ctx, value, 0);

    if (rc != NGX_OK) {
        return rc;
    }

    key = 0;

    for (i = 0; i < name->len; i++) {
        name->data[i] = ngx_tolower(name->data[i]);
        key = ngx_hash(key, name->data[i]);
    }

    vv = ngx_http_ssi_get_variable(r, name, key