ngx_http_ssi_filter_module.c

Nginx是一个高性能的HTTP和反向代理服务器

            ctx->copy_start = ctx->pos;
            ctx->copy_end = ctx->pos;
        }

        b = NULL;

        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) {

                if (ctx->output) {

                    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                                   "saved: %d", ctx->saved);

                    if (ctx->saved) {

                        if (ctx->free) {
                            cl = ctx->free;
                            ctx->free = ctx->free->next;
                            b = cl->buf;
                            ngx_memzero(b, sizeof(ngx_buf_t));

                        } else {
                            b = ngx_calloc_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;
                        }

                        b->memory = 1;
                        b->pos = ngx_http_ssi_string;
                        b->last = ngx_http_ssi_string + ctx->saved;

                        *ctx->last_out = cl;
                        ctx->last_out = &cl->next;

                        ctx->saved = 0;
                    }

                    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, ctx->buf, sizeof(ngx_buf_t));

                    b->pos = ctx->copy_start;
                    b->last = ctx->copy_end;
                    b->shadow = NULL;
                    b->last_buf = 0;
                    b->recycled = 0;

                    if (b->in_file) {
                        if (slcf->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;
                        }
                    }

                    cl->next = NULL;
                    *ctx->last_out = cl;
                    ctx->last_out = &cl->next;

                } else {
                    if (ctx->block
                        && ctx->saved + (ctx->copy_end - ctx->copy_start))
                    {
                        b = ngx_create_temp_buf(r->pool,
                               ctx->saved + (ctx->copy_end - ctx->copy_start));

                        if (b == NULL) {
                            return NGX_ERROR;
                        }

                        if (ctx->saved) {
                            b->last = ngx_cpymem(b->pos, ngx_http_ssi_string,
                                                 ctx->saved);
                        }

                        b->last = ngx_cpymem(b->last, ctx->copy_start,
                                             ctx->copy_end - ctx->copy_start);

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

                        cl->buf = b;
                        cl->next = NULL;

                        b = NULL;

                        mctx = ngx_http_get_module_ctx(r->main,
                                                   ngx_http_ssi_filter_module);
                        bl = mctx->blocks->elts;
                        for (ll = &bl[mctx->blocks->nelts - 1].bufs;
                             *ll;
                             ll = &(*ll)->next)
                        {
                            /* void */
                        }

                        *ll = cl;
                    }

                    ctx->saved = 0;
                }
            }

            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;
            }


            b = NULL;

            if (rc == NGX_OK) {

                smcf = ngx_http_get_module_main_conf(r,
                                                   ngx_http_ssi_filter_module);

                cmd = ngx_hash_find(&smcf->hash, ctx->key, ctx->command.data,
                                    ctx->command.len);

                if (cmd == NULL) {
                    if (ctx->output) {
                        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                                      "invalid SSI command: \"%V\"",
                                      &ctx->command);
                        goto ssi_error;
                    }

                    continue;
                }

                if (cmd->conditional
                    && (ctx->conditional == 0
                        || ctx->conditional > cmd->conditional))
                {
                    ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                                  "invalid context of SSI command: \"%V\"",
                                  &ctx->command);
                    goto ssi_error;
                }

                if (!ctx->output && !cmd->block) {

                    if (ctx->block) {

                        /* reconstruct the SSI command text */

                        len = 5 + ctx->command.len + 4;

                        param = ctx->params.elts;
                        for (i = 0; i < ctx->params.nelts; i++) {
                            len += 1 + param[i].key.len + 2
                                + param[i].value.len + 1;
                        }

                        b = ngx_create_temp_buf(r->pool, len);

                        if (b == NULL) {
                            return NGX_ERROR;
                        }

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

                        cl->buf = b;
                        cl->next = NULL;

                        *b->last++ = '<';
                        *b->last++ = '!';
                        *b->last++ = '-';
                        *b->last++ = '-';
                        *b->last++ = '#';

                        b->last = ngx_cpymem(b->last, ctx->command.data,
                                             ctx->command.len);

                        for (i = 0; i < ctx->params.nelts; i++) {
                            *b->last++ = ' ';
                            b->last = ngx_cpymem(b->last, param[i].key.data,
                                                 param[i].key.len);
                            *b->last++ = '=';
                            *b->last++ = '"';
                            b->last = ngx_cpymem(b->last, param[i].value.data,
                                                 param[i].value.len);
                            *b->last++ = '"';
                        }

                        *b->last++ = ' ';
                        *b->last++ = '-';
                        *b->last++ = '-';
                        *b->last++ = '>';

                        mctx = ngx_http_get_module_ctx(r->main,
                                                   ngx_http_ssi_filter_module);
                        bl = mctx->blocks->elts;
                        for (ll = &bl[mctx->blocks->nelts - 1].bufs;
                             *ll;
                             ll = &(*ll)->next)
                        {
                            /* void */
                        }

                        *ll = cl;

                        b = NULL;

                        continue;
                    }

                    if (cmd->conditional == 0) {
                        continue;
                    }
                }

                if (ctx->params.nelts > NGX_HTTP_SSI_MAX_PARAMS) {
                    ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                                  "too many SSI command paramters: \"%V\"",
                                  &ctx->command);
                    goto ssi_error;
                }

                ngx_memzero(params,
                           (NGX_HTTP_SSI_MAX_PARAMS + 1) * 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 (!prm->multiple) {
                            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;
                        }

                        for (index = prm->index; params[index]; index++) {
                            /* void */
                        }

                        params[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->flush) {

                    if (ctx->out) {
                        rc = ngx_http_ssi_output(r, ctx);

                    } else {
                        rc = ngx_http_next_body_filter(r, NULL);
                    }

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

                rc = cmd->handler(r, ctx, params);

                if (rc == NGX_OK) {
                    continue;
                }

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


            /* rc == NGX_HTTP_SSI_ERROR */

    ssi_error:

            if (slcf->silent_errors) {
                continue;
            }

            if (ctx->free) {
                cl = ctx->free;
                ctx->free = ctx->free->next;
                b = cl->buf;
                ngx_memzero(b, sizeof(ngx_buf_t));

            } else {
                b = ngx_calloc_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;
            }

            b->memory = 1;
            b->pos = ctx->errmsg.data;
            b->last = ctx->errmsg.data + ctx->errmsg.len;

            cl->next = NULL;
            *ctx->last_out = cl;
            ctx->last_out = &cl->next;

            continue;
        }

        if (ctx->buf->last_buf || ngx_buf_in_memory(ctx->buf)) {
            if (b == NULL) {
                if (ctx->free) {
                    cl = ctx->free;
                    ctx->free = ctx->free->next;
                    b = cl->buf;
                    ngx_memzero(b, sizeof(ngx_buf_t));

                } else {
                    b = ngx_calloc_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;
                }

                b->sync = 1;

                cl->next = NULL;
                *ctx->last_out = cl;
                ctx->last_out = &cl->next;
            }

            b->last_buf = ctx->buf->last_buf;
            b->shadow = ctx->buf;

            if (slcf->ignore_recycled_buffers == 0)  {
                b->recycled = ctx->buf->recycled;
            }
        }

        ctx->buf = NULL;

        ctx->saved = ctx->looked;
    }

    if (ctx->out == NULL && ctx->busy == NULL) {
        return NGX_OK;
    }

    return ngx_http_ssi_output(r, ctx);
}


static ngx_int_t
ngx_http_ssi_output(ngx_http_request_t *r, ngx_http_ssi_ctx_t *ctx)
{
    ngx_int_t     rc;
    ngx_buf_t    *b;
    ngx_chain_t  *cl;

#if 1
    b = NULL;
    for (cl = ctx->out; cl; cl = cl->next) {
        ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                       "ssi out: %p %p", cl->buf, cl->buf->pos);
        if (cl->buf == b) {
            ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0,
                          "the same buf was used in ssi");
            ngx_debug_point();
            return NGX_ERROR;
        }