ngx_http_proxy_module.c

nginx 反向代理0.7.1版本 用于实现反向代理

        return NGX_HTTP_INTERNAL_SERVER_ERROR;
    }

    r->upstream = u;

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

    ngx_http_set_ctx(r, ctx, ngx_http_proxy_module);

    plcf = ngx_http_get_module_loc_conf(r, ngx_http_proxy_module);

    if (plcf->proxy_lengths == 0) {
        ctx->vars = plcf->vars;
        u->schema = plcf->upstream.schema;
#if (NGX_HTTP_SSL)
        u->ssl = (plcf->upstream.ssl != NULL);
#endif

    } else {
        if (ngx_http_proxy_eval(r, ctx, plcf) != NGX_OK) {
            return NGX_HTTP_INTERNAL_SERVER_ERROR;
        }
    }

    u->peer.log = r->connection->log;
    u->peer.log_error = NGX_ERROR_ERR;
#if (NGX_THREADS)
    u->peer.lock = &r->connection->lock;
#endif

    u->output.tag = (ngx_buf_tag_t) &ngx_http_proxy_module;

    u->conf = &plcf->upstream;

    u->create_request = ngx_http_proxy_create_request;
    u->reinit_request = ngx_http_proxy_reinit_request;
    u->process_header = ngx_http_proxy_process_status_line;
    u->abort_request = ngx_http_proxy_abort_request;
    u->finalize_request = ngx_http_proxy_finalize_request;

    if (plcf->redirects) {
        u->rewrite_redirect = ngx_http_proxy_rewrite_redirect;
    }

    u->buffering = plcf->upstream.buffering;

    u->pipe = ngx_pcalloc(r->pool, sizeof(ngx_event_pipe_t));
    if (u->pipe == NULL) {
        return NGX_HTTP_INTERNAL_SERVER_ERROR;
    }

    u->pipe->input_filter = ngx_event_pipe_copy_input_filter;

    u->accel = 1;

    rc = ngx_http_read_client_request_body(r, ngx_http_upstream_init);

    if (rc >= NGX_HTTP_SPECIAL_RESPONSE) {
        return rc;
    }

    return NGX_DONE;
}


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)
{
    size_t     add;
    u_short    port;
    ngx_str_t  proxy;
    ngx_url_t  u;

    if (ngx_http_script_run(r, &proxy, plcf->proxy_lengths->elts, 0,
                            plcf->proxy_values->elts)
        == NULL)
    {
        return NGX_ERROR;
    }

    if (ngx_strncasecmp(proxy.data, (u_char *) "http://", 7) == 0) {

        add = 7;
        port = 80;

#if (NGX_HTTP_SSL)

    } else if (ngx_strncasecmp(proxy.data, (u_char *) "https://", 8) == 0) {

        add = 8;
        port = 443;
        r->upstream->ssl = 1;

#endif

    } else {
        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                      "invalid URL prefix in \"%V\"", &proxy);
        return NGX_ERROR;
    }

    r->upstream->schema.len = add;
    r->upstream->schema.data = proxy.data;

    ngx_memzero(&u, sizeof(ngx_url_t));

    u.url.len = proxy.len - add;
    u.url.data = proxy.data + add;
    u.default_port = port;
    u.uri_part = 1;
    u.no_resolve = 1;

    if (ngx_parse_url(r->pool, &u) != NGX_OK) {
        if (u.err) {
            ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                          "%s in upstream \"%V\"", u.err, &u.url);
        }

        return NGX_ERROR;
    }

    if (ngx_http_proxy_set_vars(r->pool, &u, &ctx->vars) != NGX_OK) {
        return NGX_ERROR;
    }

    r->upstream->resolved = ngx_pcalloc(r->pool,
                                        sizeof(ngx_http_upstream_resolved_t));
    if (r->upstream->resolved == NULL) {
        return NGX_ERROR;
    }

    r->upstream->resolved->host = u.host;
    r->upstream->resolved->port = (in_port_t) (u.no_port ? u.default_port:
                                                           u.port);
    r->upstream->resolved->default_port = u.default_port;

    return NGX_OK;
}


static ngx_int_t
ngx_http_proxy_create_request(ngx_http_request_t *r)
{
    size_t                        len, loc_len, body_len;
    uintptr_t                     escape;
    ngx_buf_t                    *b;
    ngx_str_t                     method;
    ngx_uint_t                    i, unparsed_uri;
    ngx_chain_t                  *cl, *body;
    ngx_list_part_t              *part;
    ngx_table_elt_t              *header;
    ngx_http_upstream_t          *u;
    ngx_http_proxy_ctx_t         *ctx;
    ngx_http_script_code_pt       code;
    ngx_http_script_engine_t      e, le;
    ngx_http_proxy_loc_conf_t    *plcf;
    ngx_http_script_len_code_pt   lcode;

    u = r->upstream;

    plcf = ngx_http_get_module_loc_conf(r, ngx_http_proxy_module);

    if (u->method.len) {
        /* HEAD was changed to GET to cache response */
        method = u->method;
        method.len++;

    } else if (plcf->method.len) {
        method = plcf->method;

    } else {
        method = r->method_name;
        method.len++;
    }

    len = method.len + sizeof(ngx_http_proxy_version) - 1 + sizeof(CRLF) - 1;

    escape = 0;
    loc_len = 0;
    unparsed_uri = 0;

    ctx = ngx_http_get_module_ctx(r, ngx_http_proxy_module);

    if (plcf->proxy_lengths) {
        len += ctx->vars.uri.len;

    } else if (ctx->vars.uri.len == 0 && r->valid_unparsed_uri && r == r->main)
    {
        unparsed_uri = 1;
        len += r->unparsed_uri.len;

    } else {
        loc_len = (r->valid_location && ctx->vars.uri.len) ?
                      plcf->location.len : 0;

        if (r->quoted_uri || r->internal) {
            escape = 2 * ngx_escape_uri(NULL, r->uri.data + loc_len,
                                        r->uri.len - loc_len, NGX_ESCAPE_URI);
        }

        len += ctx->vars.uri.len + r->uri.len - loc_len + escape
               + sizeof("?") - 1 + r->args.len;
    }

    ngx_http_script_flush_no_cacheable_variables(r, plcf->flushes);

    if (plcf->body_set_len) {
        le.ip = plcf->body_set_len->elts;
        le.request = r;
        le.flushed = 1;
        body_len = 0;

        while (*(uintptr_t *) le.ip) {
            lcode = *(ngx_http_script_len_code_pt *) le.ip;
            body_len += lcode(&le);
        }

        ctx->internal_body_length = body_len;
        len += body_len;
    }

    le.ip = plcf->headers_set_len->elts;
    le.request = r;
    le.flushed = 1;

    while (*(uintptr_t *) le.ip) {
        while (*(uintptr_t *) le.ip) {
            lcode = *(ngx_http_script_len_code_pt *) le.ip;
            len += lcode(&le);
        }
        le.ip += sizeof(uintptr_t);
    }


    if (plcf->upstream.pass_request_headers) {
        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;
            }

            if (ngx_hash_find(&plcf->headers_set_hash, header[i].hash,
                              header[i].lowcase_key, header[i].key.len))
            {
                continue;
            }

            len += header[i].key.len + sizeof(": ") - 1
                + header[i].value.len + sizeof(CRLF) - 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;


    /* the request line */

    b->last = ngx_copy(b->last, method.data, method.len);

    u->uri.data = b->last;

    if (plcf->proxy_lengths) {
        b->last = ngx_copy(b->last, ctx->vars.uri.data, ctx->vars.uri.len);

    } else if (unparsed_uri) {
        b->last = ngx_copy(b->last, r->unparsed_uri.data, r->unparsed_uri.len);

    } else {
        if (r->valid_location) {
            b->last = ngx_copy(b->last, ctx->vars.uri.data, ctx->vars.uri.len);
        }

        if (escape) {
            ngx_escape_uri(b->last, r->uri.data + loc_len,
                           r->uri.len - loc_len, NGX_ESCAPE_URI);
            b->last += r->uri.len - loc_len + escape;

        } else {
            b->last = ngx_copy(b->last, r->uri.data + loc_len,
                               r->uri.len - loc_len);
        }

        if (r->args.len > 0) {
            *b->last++ = '?';
            b->last = ngx_copy(b->last, r->args.data, r->args.len);
        }
    }

    u->uri.len = b->last - u->uri.data;

    b->last = ngx_cpymem(b->last, ngx_http_proxy_version,
                         sizeof(ngx_http_proxy_version) - 1);

    ngx_memzero(&e, sizeof(ngx_http_script_engine_t));

    e.ip = plcf->headers_set->elts;
    e.pos = b->last;
    e.request = r;
    e.flushed = 1;

    le.ip = plcf->headers_set_len->elts;

    while (*(uintptr_t *) le.ip) {
        lcode = *(ngx_http_script_len_code_pt *) le.ip;

        /* skip the header line name length */
        (void) lcode(&le);

        if (*(ngx_http_script_len_code_pt *) le.ip) {

            for (len = 0; *(uintptr_t *) le.ip; len += lcode(&le)) {
                lcode = *(ngx_http_script_len_code_pt *) le.ip;
            }

            e.skip = (len == sizeof(CRLF) - 1) ? 1 : 0;

        } else {
            e.skip = 0;
        }

        le.ip += sizeof(uintptr_t);

        while (*(uintptr_t *) e.ip) {
            code = *(ngx_http_script_code_pt *) e.ip;
            code((ngx_http_script_engine_t *) &e);
        }
        e.ip += sizeof(uintptr_t);
    }

    b->last = e.pos;


    if (plcf->upstream.pass_request_headers) {
        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;
            }

            if (ngx_hash_find(&plcf->headers_set_hash, header[i].hash,
                              header[i].lowcase_key, header[i].key.len))
            {
                continue;
            }

            b->last = ngx_copy(b->last, header[i].key.data, header[i].key.len);

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

            b->last = ngx_copy(b->last, header[i].value.data,
                               header[i].value.len);

            *b->last++ = CR; *b->last++ = LF;

            ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                           "http proxy header: \"%V: %V\"",
                           &header[i].key, &header[i].value);
        }
    }


    /* add "\r\n" at the header end */
    *b->last++ = CR; *b->last++ = LF;

    if (plcf->body_set) {
        e.ip = plcf->body_set->elts;
        e.pos = b->last;

        while (*(uintptr_t *) e.ip) {
            code = *(ngx_http_script_code_pt *) e.ip;
            code((ngx_http_script_engine_t *) &e);
        }

        b->last = e.pos;
    }

    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "http proxy header:\n\"%*s\"",
                   (size_t) (b->last - b->pos), b->pos);

    if (plcf->body_set == NULL && plcf->upstream.pass_request_body) {

        body = u->request_bufs;
        u->request_bufs = cl;

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

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

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

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

            body = body->next;
        }

        b->flush = 1;

    } else {
        u->request_bufs = cl;
    }

    cl->next = NULL;

    return NGX_OK;
}


static ngx_int_t
ngx_http_proxy_reinit_request(ngx_http_request_t *r)
{
    ngx_http_proxy_ctx_t  *ctx;