HTTP 请求行解析 -- ngx_http_process_request_line
2015-10-10 15:46:06 最后更新: 2015-10-11 21:44:35 访问数量：1341
HTTP 请求行的处理 -- ngx_http_process_request_line
HTTP 请求的接收 -- ngx_http_wait_request_handler
在 ngx_http_wait_request_handler 的最后调用了 ngx_http_process_request_line 函数用来处理和解析这次请求的全文
// static void ngx_http_process_request_line(ngx_event_t *rev)
// HTTP 请求行处理 {{{
static void
ngx_http_process_request_line(ngx_event_t *rev)
{
ssize_t n;
ngx_int_t rc, rv;
ngx_str_t host;
ngx_connection_t *c;
ngx_http_request_t *r;
c = rev->data;
r = c->data;
ngx_log_debug0(NGX_LOG_DEBUG_HTTP, rev->log, 0,
"http process request line");
// 已超时则退出
if (rev->timedout) {
ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out");
c->timedout = 1;
ngx_http_close_request(r, NGX_HTTP_REQUEST_TIME_OUT);
return;
}
rc = NGX_AGAIN;
for ( ;; ) {
if (rc == NGX_AGAIN) {
// 读取请求头
n = ngx_http_read_request_header(r);
if (n == NGX_AGAIN || n == NGX_ERROR) {
return;
}
}
// 解析请求行
rc = ngx_http_parse_request_line(r, r->header_in);
if (rc == NGX_OK) {
/* the request line has been parsed successfully */
r->request_line.len = r->request_end - r->request_start;
r->request_line.data = r->request_start;
r->request_length = r->header_in->pos - r->request_start;
ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0,
"http request line: \"%V\"", &r->request_line);
r->method_name.len = r->method_end - r->request_start + 1;
r->method_name.data = r->request_line.data;
if (r->http_protocol.data) {
r->http_protocol.len = r->request_end - r->http_protocol.data;
}
// 处理请求中的 URI
if (ngx_http_process_request_uri(r) != NGX_OK) {
return;
}
if (r->host_start && r->host_end) {
host.len = r->host_end - r->host_start;
host.data = r->host_start;
// 检测 host 是否合法
rc = ngx_http_validate_host(&host, r->pool, 0);
if (rc == NGX_DECLINED) {
ngx_log_error(NGX_LOG_INFO, c->log, 0,
"client sent invalid host in request line");
ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
return;
}
if (rc == NGX_ERROR) {
// 出错则关闭请求，释放资源
ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
return;
}
// 为请求设定虚拟主机
if (ngx_http_set_virtual_server(r, &host) == NGX_ERROR) {
return;
}
r->headers_in.server = host;
}
if (r->http_version < NGX_HTTP_VERSION_10) {
if (r->headers_in.server.len == 0
&& ngx_http_set_virtual_server(r, &r->headers_in.server)
== NGX_ERROR)
{
return;
}
// 请求处理
ngx_http_process_request(r);
return;
}
if (ngx_list_init(&r->headers_in.headers, r->pool, 20,
sizeof(ngx_table_elt_t))
!= NGX_OK)
{
ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
return;
}
c->log->action = "reading client request headers";
rev->handler = ngx_http_process_request_headers;
// 请求 header 处理
ngx_http_process_request_headers(rev);
return;
}
// 无需再次处理则结束请求
if (rc != NGX_AGAIN) {
/* there was error while a request line parsing */
ngx_log_error(NGX_LOG_INFO, c->log, 0,
ngx_http_client_errors[rc - NGX_HTTP_CLIENT_ERROR]);
ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
return;
}
/* NGX_AGAIN: a request line parsing is still incomplete */
// 需要再次处理请求
if (r->header_in->pos == r->header_in->end) {
rv = ngx_http_alloc_large_header_buffer(r, 1);
if (rv == NGX_ERROR) {
ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
return;
}
if (rv == NGX_DECLINED) {
r->request_line.len = r->header_in->end - r->request_start;
r->request_line.data = r->request_start;
ngx_log_error(NGX_LOG_INFO, c->log, 0,
"client sent too long URI");
ngx_http_finalize_request(r, NGX_HTTP_REQUEST_URI_TOO_LARGE);
return;
}
}
}
} // }}}
解析请求行 -- ngx_http_parse_request_line
读取到请求头部以后，紧接着就是对他的解析了，这里 nginx 调用了 ngx_http_parse_request_line 使用状态机的方式对请求头部中的请求方式、HTTP 版本、URI 等等信息进行了解析和提取
// ngx_int_t ngx_http_parse_request_line(ngx_http_request_t *r, ngx_buf_t *b)
// 解析 HTTP 请求行 {{{
ngx_int_t
ngx_http_parse_request_line(ngx_http_request_t *r, ngx_buf_t *b)
{
u_char c, ch, *p, *m;
enum {
sw_start = 0,
sw_method,
sw_spaces_before_uri,
sw_schema,
sw_schema_slash,
sw_schema_slash_slash,
sw_host_start,
sw_host,
sw_host_end,
sw_host_ip_literal,
sw_port,
sw_host_http_09,
sw_after_slash_in_uri,
sw_check_uri,
sw_check_uri_http_09,
sw_uri,
sw_http_09,
sw_http_H,
sw_http_HT,
sw_http_HTT,
sw_http_HTTP,
sw_first_major_digit,
sw_major_digit,
sw_first_minor_digit,
sw_minor_digit,
sw_spaces_after_digit,
sw_almost_done
} state;
state = r->state;
for (p = b->pos; p < b->last; p++) {
ch = *p;
switch (state) {
/* HTTP methods: GET, HEAD, POST */
case sw_start:
r->request_start = p;
if (ch == CR || ch == LF) {
break;
}
if ((ch < 'A' || ch > 'Z') && ch != '_') {
return NGX_HTTP_PARSE_INVALID_METHOD;
}
state = sw_method;
break;
case sw_method:
if (ch == ' ') {
r->method_end = p - 1;
m = r->request_start;
switch (p - m) {
case 3:
if (ngx_str3_cmp(m, 'G', 'E', 'T', ' ')) {
r->method = NGX_HTTP_GET;
break;
}
if (ngx_str3_cmp(m, 'P', 'U', 'T', ' ')) {
r->method = NGX_HTTP_PUT;
break;
}
break;
case 4:
if (m[1] == 'O') {
if (ngx_str3Ocmp(m, 'P', 'O', 'S', 'T')) {
r->method = NGX_HTTP_POST;
break;
}
if (ngx_str3Ocmp(m, 'C', 'O', 'P', 'Y')) {
r->method = NGX_HTTP_COPY;
break;
}
if (ngx_str3Ocmp(m, 'M', 'O', 'V', 'E')) {
r->method = NGX_HTTP_MOVE;
break;
}
if (ngx_str3Ocmp(m, 'L', 'O', 'C', 'K')) {
r->method = NGX_HTTP_LOCK;
break;
}
} else {
if (ngx_str4cmp(m, 'H', 'E', 'A', 'D')) {
r->method = NGX_HTTP_HEAD;
break;
}
}
break;
case 5:
if (ngx_str5cmp(m, 'M', 'K', 'C', 'O', 'L')) {
r->method = NGX_HTTP_MKCOL;
break;
}
if (ngx_str5cmp(m, 'P', 'A', 'T', 'C', 'H')) {
r->method = NGX_HTTP_PATCH;
break;
}
if (ngx_str5cmp(m, 'T', 'R', 'A', 'C', 'E')) {
r->method = NGX_HTTP_TRACE;
break;
}
break;
case 6:
if (ngx_str6cmp(m, 'D', 'E', 'L', 'E', 'T', 'E')) {
r->method = NGX_HTTP_DELETE;
break;
}
if (ngx_str6cmp(m, 'U', 'N', 'L', 'O', 'C', 'K')) {
r->method = NGX_HTTP_UNLOCK;
break;
}
break;
case 7:
if (ngx_str7_cmp(m, 'O', 'P', 'T', 'I', 'O', 'N', 'S', ' '))
{
r->method = NGX_HTTP_OPTIONS;
}
break;
case 8:
if (ngx_str8cmp(m, 'P', 'R', 'O', 'P', 'F', 'I', 'N', 'D'))
{
r->method = NGX_HTTP_PROPFIND;
}
break;
case 9:
if (ngx_str9cmp(m,
'P', 'R', 'O', 'P', 'P', 'A', 'T', 'C', 'H'))
{
r->method = NGX_HTTP_PROPPATCH;
}
break;
}
state = sw_spaces_before_uri;
break;
}
if ((ch < 'A' || ch > 'Z') && ch != '_') {
return NGX_HTTP_PARSE_INVALID_METHOD;
}
break;
/* space* before URI */
case sw_spaces_before_uri:
if (ch == '/') {
r->uri_start = p;
state = sw_after_slash_in_uri;
break;
}
c = (u_char) (ch | 0x20);
if (c >= 'a' && c <= 'z') {
r->schema_start = p;
state = sw_schema;
break;
}
switch (ch) {
case ' ':
break;
default:
return NGX_HTTP_PARSE_INVALID_REQUEST;
}
break;
case sw_schema:
c = (u_char) (ch | 0x20);
if (c >= 'a' && c <= 'z') {
break;
}
switch (ch) {
case ':':
r->schema_end = p;
state = sw_schema_slash;
break;
default:
return NGX_HTTP_PARSE_INVALID_REQUEST;
}
break;
case sw_schema_slash:
switch (ch) {
case '/':
state = sw_schema_slash_slash;
break;
default:
return NGX_HTTP_PARSE_INVALID_REQUEST;
}
break;
case sw_schema_slash_slash:
switch (ch) {
case '/':
state = sw_host_start;
break;
default:
return NGX_HTTP_PARSE_INVALID_REQUEST;
}
break;
case sw_host_start:
r->host_start = p;
if (ch == '[') {
state = sw_host_ip_literal;
break;
}
state = sw_host;
/* fall through */
case sw_host:
c = (u_char) (ch | 0x20);
if (c >= 'a' && c <= 'z') {
break;
}
if ((ch >= '0' && ch <= '9') || ch == '.' || ch == '-') {
break;
}
/* fall through */
case sw_host_end:
r->host_end = p;
switch (ch) {
case ':':
state = sw_port;
break;
case '/':
r->uri_start = p;
state = sw_after_slash_in_uri;
break;
case ' ':
/*
* use single "/" from request line to preserve pointers,
* if request line will be copied to large client buffer
*/
r->uri_start = r->schema_end + 1;
r->uri_end = r->schema_end + 2;
state = sw_host_http_09;
break;
default:
return NGX_HTTP_PARSE_INVALID_REQUEST;
}
break;
case sw_host_ip_literal:
if (ch >= '0' && ch <= '9') {
break;
}
c = (u_char) (ch | 0x20);
if (c >= 'a' && c <= 'z') {
break;
}
switch (ch) {
case ':':
break;
case ']':
state = sw_host_end;
break;
case '-':
case '.':
case '_':
case '~':
/* unreserved */
break;
case '!':
case '$':
case '&':
case '\'':
case '(':
case ')':
case '*':
case '+':
case ',':
case ';':
case '=':
/* sub-delims */
break;
default:
return NGX_HTTP_PARSE_INVALID_REQUEST;
}
break;
case sw_port:
if (ch >= '0' && ch <= '9') {
break;
}
switch (ch) {
case '/':
r->port_end = p;
r->uri_start = p;
state = sw_after_slash_in_uri;
break;
case ' ':
r->port_end = p;
/*
* use single "/" from request line to preserve pointers,
* if request line will be copied to large client buffer
*/
r->uri_start = r->schema_end + 1;
r->uri_end = r->schema_end + 2;
state = sw_host_http_09;
break;
default:
return NGX_HTTP_PARSE_INVALID_REQUEST;
}
break;
/* space+ after "http://host[:port] " */
case sw_host_http_09:
switch (ch) {
case ' ':
break;
case CR:
r->http_minor = 9;
state = sw_almost_done;
break;
case LF:
r->http_minor = 9;
goto done;
case 'H':
r->http_protocol.data = p;
state = sw_http_H;
break;
default:
return NGX_HTTP_PARSE_INVALID_REQUEST;
}
break;
/* check "/.", "//", "%", and "\" (Win32) in URI */
case sw_after_slash_in_uri:
if (usual[ch >> 5] & (1 << (ch & 0x1f))) {
state = sw_check_uri;
break;
}
switch (ch) {
case ' ':
r->uri_end = p;
state = sw_check_uri_http_09;
break;
case CR:
r->uri_end = p;
r->http_minor = 9;
state = sw_almost_done;
break;
case LF:
r->uri_end = p;
r->http_minor = 9;
goto done;
case '.':
r->complex_uri = 1;
state = sw_uri;
break;
case '%':
r->quoted_uri = 1;
state = sw_uri;
break;
case '/':
r->complex_uri = 1;
state = sw_uri;
break;
#if (NGX_WIN32)
case '\\':
r->complex_uri = 1;
state = sw_uri;
break;
#endif
case '?':
r->args_start = p + 1;
state = sw_uri;
break;
case '#':
r->complex_uri = 1;
state = sw_uri;
break;
case '+':
r->plus_in_uri = 1;
break;
case '\0':
return NGX_HTTP_PARSE_INVALID_REQUEST;
default:
state = sw_check_uri;
break;
}
break;
/* check "/", "%" and "\" (Win32) in URI */
case sw_check_uri:
if (usual[ch >> 5] & (1 << (ch & 0x1f))) {
break;
}
switch (ch) {
case '/':
#if (NGX_WIN32)
if (r->uri_ext == p) {
r->complex_uri = 1;
state = sw_uri;
break;
}
#endif
r->uri_ext = NULL;
state = sw_after_slash_in_uri;
break;
case '.':
r->uri_ext = p + 1;
break;
case ' ':
r->uri_end = p;
state = sw_check_uri_http_09;
break;
case CR:
r->uri_end = p;
r->http_minor = 9;
state = sw_almost_done;
break;
case LF:
r->uri_end = p;
r->http_minor = 9;
goto done;
#if (NGX_WIN32)
case '\\':
r->complex_uri = 1;
state = sw_after_slash_in_uri;
break;
#endif
case '%':
r->quoted_uri = 1;
state = sw_uri;
break;
case '?':
r->args_start = p + 1;
state = sw_uri;
break;
case '#':
r->complex_uri = 1;
state = sw_uri;
break;
case '+':
r->plus_in_uri = 1;
break;
case '\0':
return NGX_HTTP_PARSE_INVALID_REQUEST;
}
break;
/* space+ after URI */
case sw_check_uri_http_09:
switch (ch) {
case ' ':
break;
case CR:
r->http_minor = 9;
state = sw_almost_done;
break;
case LF:
r->http_minor = 9;
goto done;
case 'H':
r->http_protocol.data = p;
state = sw_http_H;
break;
default:
r->space_in_uri = 1;
state = sw_check_uri;
p--;
break;
}
break;
/* URI */
case sw_uri:
if (usual[ch >> 5] & (1 << (ch & 0x1f))) {
break;
}
switch (ch) {
case ' ':
r->uri_end = p;
state = sw_http_09;
break;
case CR:
r->uri_end = p;
r->http_minor = 9;
state = sw_almost_done;
break;
case LF:
r->uri_end = p;
r->http_minor = 9;
goto done;
case '#':
r->complex_uri = 1;
break;
case '\0':
return NGX_HTTP_PARSE_INVALID_REQUEST;
}
break;
/* space+ after URI */
case sw_http_09:
switch (ch) {
case ' ':
break;
case CR:
r->http_minor = 9;
state = sw_almost_done;
break;
case LF:
r->http_minor = 9;
goto done;
case 'H':
r->http_protocol.data = p;
state = sw_http_H;
break;
default:
r->space_in_uri = 1;
state = sw_uri;
p--;
break;
}
break;
case sw_http_H:
switch (ch) {
case 'T':
state = sw_http_HT;
break;
default:
return NGX_HTTP_PARSE_INVALID_REQUEST;
}
break;
case sw_http_HT:
switch (ch) {
case 'T':
state = sw_http_HTT;
break;
default:
return NGX_HTTP_PARSE_INVALID_REQUEST;
}
break;
case sw_http_HTT:
switch (ch) {
case 'P':
state = sw_http_HTTP;
break;
default:
return NGX_HTTP_PARSE_INVALID_REQUEST;
}
break;
case sw_http_HTTP:
switch (ch) {
case '/':
state = sw_first_major_digit;
break;
default:
return NGX_HTTP_PARSE_INVALID_REQUEST;
}
break;
/* first digit of major HTTP version */
case sw_first_major_digit:
if (ch < '1' || ch > '9') {
return NGX_HTTP_PARSE_INVALID_REQUEST;
}
r->http_major = ch - '0';
state = sw_major_digit;
break;
/* major HTTP version or dot */
case sw_major_digit:
if (ch == '.') {
state = sw_first_minor_digit;
break;
}
if (ch < '0' || ch > '9') {
return NGX_HTTP_PARSE_INVALID_REQUEST;
}
r->http_major = r->http_major * 10 + ch - '0';
break;
/* first digit of minor HTTP version */
case sw_first_minor_digit:
if (ch < '0' || ch > '9') {
return NGX_HTTP_PARSE_INVALID_REQUEST;
}
r->http_minor = ch - '0';
state = sw_minor_digit;
break;
/* minor HTTP version or end of request line */
case sw_minor_digit:
if (ch == CR) {
state = sw_almost_done;
break;
}
if (ch == LF) {
goto done;
}
if (ch == ' ') {
state = sw_spaces_after_digit;
break;
}
if (ch < '0' || ch > '9') {
return NGX_HTTP_PARSE_INVALID_REQUEST;
}
r->http_minor = r->http_minor * 10 + ch - '0';
break;
case sw_spaces_after_digit:
switch (ch) {
case ' ':
break;
case CR:
state = sw_almost_done;
break;
case LF:
goto done;
default:
return NGX_HTTP_PARSE_INVALID_REQUEST;
}
break;
/* end of request line */
case sw_almost_done:
r->request_end = p - 1;
switch (ch) {
case LF:
goto done;
default:
return NGX_HTTP_PARSE_INVALID_REQUEST;
}
}
}
b->pos = p;
r->state = state;
return NGX_AGAIN;
done:
b->pos = p + 1;
if (r->request_end == NULL) {
r->request_end = p;
}
r->http_version = r->http_major * 1000 + r->http_minor;
r->state = sw_start;
if (r->http_version == 9 && r->method != NGX_HTTP_GET) {
return NGX_HTTP_PARSE_INVALID_09_METHOD;
}
return NGX_OK;
} // }}}
处理请求 URI -- ngx_http_parse_request_line
接着 nginx 对于已经提取出来的 URI 调用 ngx_http_process_request_uri 进行了分析
// ngx_int_t ngx_http_process_request_uri(ngx_http_request_t *r)
// 处理 HTTP 请求中的 URI {{{
ngx_int_t
ngx_http_process_request_uri(ngx_http_request_t *r)
{
ngx_http_core_srv_conf_t *cscf;
if (r->args_start) {
r->uri.len = r->args_start - 1 - r->uri_start;
} else {
r->uri.len = r->uri_end - r->uri_start;
}
if (r->complex_uri || r->quoted_uri) {
r->uri.data = ngx_pnalloc(r->pool, r->uri.len + 1);
if (r->uri.data == NULL) {
ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
return NGX_ERROR;
}
cscf = ngx_http_get_module_srv_conf(r, ngx_http_core_module);
if (ngx_http_parse_complex_uri(r, cscf->merge_slashes) != NGX_OK) {
r->uri.len = 0;
ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
"client sent invalid request");
ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
return NGX_ERROR;
}
} else {
r->uri.data = r->uri_start;
}
r->unparsed_uri.len = r->uri_end - r->uri_start;
r->unparsed_uri.data = r->uri_start;
r->valid_unparsed_uri = r->space_in_uri ? 0 : 1;
if (r->uri_ext) {
if (r->args_start) {
r->exten.len = r->args_start - 1 - r->uri_ext;
} else {
r->exten.len = r->uri_end - r->uri_ext;
}
r->exten.data = r->uri_ext;
}
if (r->args_start && r->uri_end > r->args_start) {
r->args.len = r->uri_end - r->args_start;
r->args.data = r->args_start;
}
#if (NGX_WIN32)
{
u_char *p, *last;
p = r->uri.data;
last = r->uri.data + r->uri.len;
while (p < last) {
if (*p++ == ':') {
/*
* this check covers "::$data", "::$index_allocation" and
* ":$i30:$index_allocation"
*/
if (p < last && *p == '$') {
ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
"client sent unsafe win32 URI");
ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
return NGX_ERROR;
}
}
}
p = r->uri.data + r->uri.len - 1;
while (p > r->uri.data) {
if (*p == ' ') {
p--;
continue;
}
if (*p == '.') {
p--;
continue;
}
break;
}
if (p != r->uri.data + r->uri.len - 1) {
r->uri.len = p + 1 - r->uri.data;
ngx_http_set_exten(r);
}
}
#endif
ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
"http uri: \"%V\"", &r->uri);
ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
"http args: \"%V\"", &r->args);
ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
"http exten: \"%V\"", &r->exten);
return NGX_OK;
} // }}}
检测 host 是否合法 -- ngx_http_validate_host
// static ngx_int_t
// ngx_http_validate_host(ngx_str_t *host, ngx_pool_t *pool, ngx_uint_t alloc)
// 检测 host 是否合法 {{{
static ngx_int_t
ngx_http_validate_host(ngx_str_t *host, ngx_pool_t *pool, ngx_uint_t alloc)
{
u_char *h, ch;
size_t i, dot_pos, host_len;
enum {
sw_usual = 0,
sw_literal,
sw_rest
} state;
dot_pos = host->len;
host_len = host->len;
h = host->data;
state = sw_usual;
for (i = 0; i < host->len; i++) {
ch = h[i];
switch (ch) {
case '.':
if (dot_pos == i - 1) {
return NGX_DECLINED;
}
dot_pos = i;
break;
case ':':
if (state == sw_usual) {
host_len = i;
state = sw_rest;
}
break;
case '[':
if (i == 0) {
state = sw_literal;
}
break;
case ']':
if (state == sw_literal) {
host_len = i + 1;
state = sw_rest;
}
break;
case '\0':
return NGX_DECLINED;
default:
if (ngx_path_separator(ch)) {
return NGX_DECLINED;
}
if (ch >= 'A' && ch <= 'Z') {
alloc = 1;
}
break;
}
}
if (dot_pos == host_len - 1) {
host_len--;
}
if (host_len == 0) {
return NGX_DECLINED;
}
if (alloc) {
host->data = ngx_pnalloc(pool, host_len);
if (host->data == NULL) {
return NGX_ERROR;
}
ngx_strlow(host->data, h, host_len);
}
host->len = host_len;
return NGX_OK;
} // }}}
设置请求的虚拟主机 -- ngx_http_set_virtual_server
紧接着，根据提取出来的合法 host 调用 ngx_http_set_virtual_server 函数设置了请求描述结构对应的虚拟主机
// static ngx_int_t
// ngx_http_set_virtual_server(ngx_http_request_t *r, ngx_str_t *host)
// 为请求设定虚拟主机 {{{
static ngx_int_t
ngx_http_set_virtual_server(ngx_http_request_t *r, ngx_str_t *host)
{
ngx_int_t rc;
ngx_http_connection_t *hc;
ngx_http_core_loc_conf_t *clcf;
ngx_http_core_srv_conf_t *cscf;
#if (NGX_SUPPRESS_WARN)
cscf = NULL;
#endif
hc = r->http_connection;
#if (NGX_HTTP_SSL && defined SSL_CTRL_SET_TLSEXT_HOSTNAME)
// HTTPS 协议域名解析
if (hc->ssl_servername) {
if (hc->ssl_servername->len == host->len
&& ngx_strncmp(hc->ssl_servername->data,
host->data, host->len) == 0)
{
#if (NGX_PCRE)
// 根据正则表达式解析域名
if (hc->ssl_servername_regex
&& ngx_http_regex_exec(r, hc->ssl_servername_regex,
hc->ssl_servername) != NGX_OK)
{
ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
return NGX_ERROR;
}
#endif
return NGX_OK;
}
}
#endif
// 根据 host 查询对应的虚拟主机
rc = ngx_http_find_virtual_server(r->connection,
hc->addr_conf->virtual_names,
host, r, &cscf);
if (rc == NGX_ERROR) {
ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
return NGX_ERROR;
}
#if (NGX_HTTP_SSL && defined SSL_CTRL_SET_TLSEXT_HOSTNAME)
if (hc->ssl_servername) {
ngx_http_ssl_srv_conf_t *sscf;
if (rc == NGX_DECLINED) {
cscf = hc->addr_conf->default_server;
rc = NGX_OK;
}
sscf = ngx_http_get_module_srv_conf(cscf->ctx, ngx_http_ssl_module);
if (sscf->verify) {
ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
"client attempted to request the server name "
"different from that one was negotiated");
// 请求的最后处理并中止
ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
return NGX_ERROR;
}
}
#endif
if (rc == NGX_DECLINED) {
return NGX_OK;
}
r->srv_conf = cscf->ctx->srv_conf;
r->loc_conf = cscf->ctx->loc_conf;
clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);
ngx_http_set_connection_log(r->connection, clcf->error_log);
return NGX_OK;
} // }}}
在这个函数中，首先对 HTTPS 协议进行了处理，使用 PCRE 解析了对应的正则表达式
然后调用 ngx_http_find_virtual_server 在虚拟主机哈希表中获取了它所对应的虚拟主机
// static ngx_int_t
// ngx_http_find_virtual_server(ngx_connection_t *c,
// ngx_http_virtual_names_t *virtual_names, ngx_str_t *host,
// ngx_http_request_t *r, ngx_http_core_srv_conf_t **cscfp)
// 在虚拟主机 hash 表中查找 host 对应的虚拟主机 {{{
static ngx_int_t
ngx_http_find_virtual_server(ngx_connection_t *c,
ngx_http_virtual_names_t *virtual_names, ngx_str_t *host,
ngx_http_request_t *r, ngx_http_core_srv_conf_t **cscfp)
{
ngx_http_core_srv_conf_t *cscf;
if (virtual_names == NULL) {
return NGX_DECLINED;
}
// 从哈希表中获取相应的值
cscf = ngx_hash_find_combined(&virtual_names->names,
ngx_hash_key(host->data, host->len),
host->data, host->len);
if (cscf) {
*cscfp = cscf;
return NGX_OK;
}
#if (NGX_PCRE)
if (host->len && virtual_names->nregex) {
ngx_int_t n;
ngx_uint_t i;
ngx_http_server_name_t *sn;
sn = virtual_names->regex;
#if (NGX_HTTP_SSL && defined SSL_CTRL_SET_TLSEXT_HOSTNAME)
if (r == NULL) {
ngx_http_connection_t *hc;
for (i = 0; i < virtual_names->nregex; i++) {
n = ngx_regex_exec(sn[i].regex->regex, host, NULL, 0);
if (n == NGX_REGEX_NO_MATCHED) {
continue;
}
if (n >= 0) {
hc = c->data;
hc->ssl_servername_regex = sn[i].regex;
*cscfp = sn[i].server;
return NGX_OK;
}
ngx_log_error(NGX_LOG_ALERT, c->log, 0,
ngx_regex_exec_n " failed: %i "
"on \"%V\" using \"%V\"",
n, host, &sn[i].regex->name);
return NGX_ERROR;
}
return NGX_DECLINED;
}
#endif /* NGX_HTTP_SSL && defined SSL_CTRL_SET_TLSEXT_HOSTNAME */
for (i = 0; i < virtual_names->nregex; i++) {
// 调用 pcre_exec 解析正则表达式
n = ngx_http_regex_exec(r, sn[i].regex, host);
if (n == NGX_DECLINED) {
continue;
}
if (n == NGX_OK) {
*cscfp = sn[i].server;
return NGX_OK;
}
return NGX_ERROR;
}
}
#endif /* NGX_PCRE */
return NGX_DECLINED;
} // }}}
ngx_http_find_virtual_server 是调用 ngx_hash_find_combined 实现哈希表的查询的，这个函数我们在介绍哈希表的时候提到了
// void *
// ngx_hash_find_combined(ngx_hash_combined_t *hash, ngx_uint_t key,
// u_char *name, size_t len)
// 按照前置、后置散列表规则查询指定字符串 {{{
void *
ngx_hash_find_combined(ngx_hash_combined_t *hash, ngx_uint_t key, u_char *name,
size_t len)
{
void *value;
if (hash->hash.buckets) {
value = ngx_hash_find(&hash->hash, key, name, len);
if (value) {
return value;
}
}
if (len == 0) {
return NULL;
}
if (hash->wc_head && hash->wc_head->hash.buckets) {
value = ngx_hash_find_wc_head(hash->wc_head, name, len);
if (value) {
return value;
}
}
if (hash->wc_tail && hash->wc_tail->hash.buckets) {
value = ngx_hash_find_wc_tail(hash->wc_tail, name, len);
if (value) {
return value;
}
}
return NULL;
} // }}}
请求头解析 -- ngx_http_process_request_headers
在上面的简介中，我们知道对于 HTTP 0.9 协议的请求来说是不包含 header 的，因此最后判断了一下版本，对于 HTTP/1.0 以上版本则进入 HEADER 的解析 -- ngx_http_process_request_headers，而针对 HTTP/0.9 版本则直接调用 ngx_http_process_request 处理请求内容