* [Qemu-devel] [PATCH v1 0/2] Improve websockets server error reporting @ 2017-09-06 10:40 Daniel P. Berrange 2017-09-06 10:40 ` [Qemu-devel] [PATCH v1 1/2] io: send proper HTTP response for websocket errors Daniel P. Berrange 2017-09-06 10:40 ` [Qemu-devel] [PATCH v1 2/2] io: include full error message in websocket handshake trace Daniel P. Berrange 0 siblings, 2 replies; 6+ messages in thread From: Daniel P. Berrange @ 2017-09-06 10:40 UTC (permalink / raw) To: qemu-devel; +Cc: Brian Rak, Daniel P. Berrange The websockets server gives no useful error response to the client nor provides any way to debug errors no the server Daniel P. Berrange (2): io: send proper HTTP response for websocket errors io: include full error message in websocket handshake trace io/channel-websock.c | 184 ++++++++++++++++++++++++++++++++++++++------------- io/trace-events | 2 +- 2 files changed, 138 insertions(+), 48 deletions(-) -- 2.13.5 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Qemu-devel] [PATCH v1 1/2] io: send proper HTTP response for websocket errors 2017-09-06 10:40 [Qemu-devel] [PATCH v1 0/2] Improve websockets server error reporting Daniel P. Berrange @ 2017-09-06 10:40 ` Daniel P. Berrange 2017-09-06 18:06 ` Philippe Mathieu-Daudé 2017-09-06 10:40 ` [Qemu-devel] [PATCH v1 2/2] io: include full error message in websocket handshake trace Daniel P. Berrange 1 sibling, 1 reply; 6+ messages in thread From: Daniel P. Berrange @ 2017-09-06 10:40 UTC (permalink / raw) To: qemu-devel; +Cc: Brian Rak, Daniel P. Berrange When any error occurs while processing the websockets handshake, QEMU just terminates the connection abruptly. This is in violation of the HTTP specs and does not help the client understand what they did wrong. This is particularly bad when the client gives the wrong path, as a "404 Not Found" would be very helpful. Refactor the handshake code so that it always sends a response to the client unless there was an I/O error. Fixes bug: #1715186 Signed-off-by: Daniel P. Berrange <berrange@redhat.com> --- io/channel-websock.c | 179 ++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 134 insertions(+), 45 deletions(-) diff --git a/io/channel-websock.c b/io/channel-websock.c index 5a3badbec2..b9cc5a1371 100644 --- a/io/channel-websock.c +++ b/io/channel-websock.c @@ -44,13 +44,39 @@ #define QIO_CHANNEL_WEBSOCK_CONNECTION_UPGRADE "Upgrade" #define QIO_CHANNEL_WEBSOCK_UPGRADE_WEBSOCKET "websocket" -#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RESPONSE \ +#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON \ + "Server: QEMU VNC\r\n" \ + "Date: %s\r\n" + +#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_OK \ "HTTP/1.1 101 Switching Protocols\r\n" \ + QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON \ "Upgrade: websocket\r\n" \ "Connection: Upgrade\r\n" \ "Sec-WebSocket-Accept: %s\r\n" \ "Sec-WebSocket-Protocol: binary\r\n" \ "\r\n" +#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_NOT_FOUND \ + "HTTP/1.1 404 Not Found\r\n" \ + QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON \ + "Connection: close\r\n" \ + "\r\n" +#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_BAD_REQUEST \ + "HTTP/1.1 400 Bad Request\r\n" \ + QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON \ + "Connection: close\r\n" \ + "Sec-WebSocket-Version: 13\r\n" \ + "\r\n" +#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_SERVER_ERR \ + "HTTP/1.1 500 Internal Server Error\r\n" \ + QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON \ + "Connection: close\r\n" \ + "\r\n" +#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_TOO_LARGE \ + "HTTP/1.1 403 Request Entity Too Large\r\n" \ + QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON \ + "Connection: close\r\n" \ + "\r\n" #define QIO_CHANNEL_WEBSOCK_HANDSHAKE_DELIM "\r\n" #define QIO_CHANNEL_WEBSOCK_HANDSHAKE_END "\r\n\r\n" #define QIO_CHANNEL_WEBSOCK_SUPPORTED_VERSION "13" @@ -123,8 +149,43 @@ enum { QIO_CHANNEL_WEBSOCK_OPCODE_PONG = 0xA }; +static void qio_channel_websock_handshake_send_res(QIOChannelWebsock *ioc, + const char *resmsg, + ...) +{ + va_list vargs; + char *response = NULL; + size_t responselen; + + va_start(vargs, resmsg); + response = g_strdup_vprintf(resmsg, vargs); + responselen = strlen(response); + buffer_reserve(&ioc->encoutput, responselen); + buffer_append(&ioc->encoutput, response, responselen); + va_end(vargs); +} + +static gchar *qio_channel_websock_date_str(void) +{ + GTimeZone *utc = g_time_zone_new_utc(); + GDateTime *now = g_date_time_new_now(utc); + gchar *ret = g_date_time_format(now, "%a, %d %b %Y %H:%M:%S GMT"); + g_date_time_unref(now); + g_time_zone_unref(utc); + return ret; +} + +static void qio_channel_websock_handshake_send_res_err(QIOChannelWebsock *ioc, + const char *resdata) +{ + char *date = qio_channel_websock_date_str(); + qio_channel_websock_handshake_send_res(ioc, resdata, date); + g_free(date); +} + static size_t -qio_channel_websock_extract_headers(char *buffer, +qio_channel_websock_extract_headers(QIOChannelWebsock *ioc, + char *buffer, QIOChannelWebsockHTTPHeader *hdrs, size_t nhdrsalloc, Error **errp) @@ -145,7 +206,7 @@ qio_channel_websock_extract_headers(char *buffer, nl = strstr(buffer, QIO_CHANNEL_WEBSOCK_HANDSHAKE_DELIM); if (!nl) { error_setg(errp, "Missing HTTP header delimiter"); - return 0; + goto bad_request; } *nl = '\0'; @@ -158,18 +219,20 @@ qio_channel_websock_extract_headers(char *buffer, if (!g_str_equal(buffer, QIO_CHANNEL_WEBSOCK_HTTP_METHOD)) { error_setg(errp, "Unsupported HTTP method %s", buffer); - return 0; + goto bad_request; } buffer = tmp + 1; tmp = strchr(buffer, ' '); if (!tmp) { error_setg(errp, "Missing HTTP version delimiter"); - return 0; + goto bad_request; } *tmp = '\0'; if (!g_str_equal(buffer, QIO_CHANNEL_WEBSOCK_HTTP_PATH)) { + qio_channel_websock_handshake_send_res_err( + ioc, QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_NOT_FOUND); error_setg(errp, "Unexpected HTTP path %s", buffer); return 0; } @@ -178,7 +241,7 @@ qio_channel_websock_extract_headers(char *buffer, if (!g_str_equal(buffer, QIO_CHANNEL_WEBSOCK_HTTP_VERSION)) { error_setg(errp, "Unsupported HTTP version %s", buffer); - return 0; + goto bad_request; } buffer = nl + strlen(QIO_CHANNEL_WEBSOCK_HANDSHAKE_DELIM); @@ -203,7 +266,7 @@ qio_channel_websock_extract_headers(char *buffer, sep = strchr(buffer, ':'); if (!sep) { error_setg(errp, "Malformed HTTP header"); - return 0; + goto bad_request; } *sep = '\0'; sep++; @@ -213,7 +276,7 @@ qio_channel_websock_extract_headers(char *buffer, if (nhdrs >= nhdrsalloc) { error_setg(errp, "Too many HTTP headers"); - return 0; + goto bad_request; } hdr = &hdrs[nhdrs++]; @@ -231,6 +294,11 @@ qio_channel_websock_extract_headers(char *buffer, } while (nl != NULL); return nhdrs; + + bad_request: + qio_channel_websock_handshake_send_res_err( + ioc, QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_BAD_REQUEST); + return 0; } static const char * @@ -250,14 +318,14 @@ qio_channel_websock_find_header(QIOChannelWebsockHTTPHeader *hdrs, } -static int qio_channel_websock_handshake_send_response(QIOChannelWebsock *ioc, - const char *key, - Error **errp) +static void qio_channel_websock_handshake_send_res_ok(QIOChannelWebsock *ioc, + const char *key, + Error **errp) { char combined_key[QIO_CHANNEL_WEBSOCK_CLIENT_KEY_LEN + QIO_CHANNEL_WEBSOCK_GUID_LEN + 1]; - char *accept = NULL, *response = NULL; - size_t responselen; + char *accept = NULL; + char *date = qio_channel_websock_date_str(); g_strlcpy(combined_key, key, QIO_CHANNEL_WEBSOCK_CLIENT_KEY_LEN + 1); g_strlcat(combined_key, QIO_CHANNEL_WEBSOCK_GUID, @@ -271,105 +339,110 @@ static int qio_channel_websock_handshake_send_response(QIOChannelWebsock *ioc, QIO_CHANNEL_WEBSOCK_GUID_LEN, &accept, errp) < 0) { - return -1; + qio_channel_websock_handshake_send_res_err( + ioc, QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_SERVER_ERR); + return; } - response = g_strdup_printf(QIO_CHANNEL_WEBSOCK_HANDSHAKE_RESPONSE, accept); - responselen = strlen(response); - buffer_reserve(&ioc->encoutput, responselen); - buffer_append(&ioc->encoutput, response, responselen); + qio_channel_websock_handshake_send_res( + ioc, QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_OK, date, accept); + g_free(date); g_free(accept); - g_free(response); - return 0; + return; } -static int qio_channel_websock_handshake_process(QIOChannelWebsock *ioc, - char *buffer, - Error **errp) +static void qio_channel_websock_handshake_process(QIOChannelWebsock *ioc, + char *buffer, + Error **errp) { QIOChannelWebsockHTTPHeader hdrs[32]; size_t nhdrs = G_N_ELEMENTS(hdrs); const char *protocols = NULL, *version = NULL, *key = NULL, *host = NULL, *connection = NULL, *upgrade = NULL; - nhdrs = qio_channel_websock_extract_headers(buffer, hdrs, nhdrs, errp); + nhdrs = qio_channel_websock_extract_headers(ioc, buffer, hdrs, nhdrs, errp); if (!nhdrs) { - return -1; + return; } protocols = qio_channel_websock_find_header( hdrs, nhdrs, QIO_CHANNEL_WEBSOCK_HEADER_PROTOCOL); if (!protocols) { error_setg(errp, "Missing websocket protocol header data"); - return -1; + goto bad_request; } version = qio_channel_websock_find_header( hdrs, nhdrs, QIO_CHANNEL_WEBSOCK_HEADER_VERSION); if (!version) { error_setg(errp, "Missing websocket version header data"); - return -1; + goto bad_request; } key = qio_channel_websock_find_header( hdrs, nhdrs, QIO_CHANNEL_WEBSOCK_HEADER_KEY); if (!key) { error_setg(errp, "Missing websocket key header data"); - return -1; + goto bad_request; } host = qio_channel_websock_find_header( hdrs, nhdrs, QIO_CHANNEL_WEBSOCK_HEADER_HOST); if (!host) { error_setg(errp, "Missing websocket host header data"); - return -1; + goto bad_request; } connection = qio_channel_websock_find_header( hdrs, nhdrs, QIO_CHANNEL_WEBSOCK_HEADER_CONNECTION); if (!connection) { error_setg(errp, "Missing websocket connection header data"); - return -1; + goto bad_request; } upgrade = qio_channel_websock_find_header( hdrs, nhdrs, QIO_CHANNEL_WEBSOCK_HEADER_UPGRADE); if (!upgrade) { error_setg(errp, "Missing websocket upgrade header data"); - return -1; + goto bad_request; } if (!g_strrstr(protocols, QIO_CHANNEL_WEBSOCK_PROTOCOL_BINARY)) { error_setg(errp, "No '%s' protocol is supported by client '%s'", QIO_CHANNEL_WEBSOCK_PROTOCOL_BINARY, protocols); - return -1; + goto bad_request; } if (!g_str_equal(version, QIO_CHANNEL_WEBSOCK_SUPPORTED_VERSION)) { error_setg(errp, "Version '%s' is not supported by client '%s'", QIO_CHANNEL_WEBSOCK_SUPPORTED_VERSION, version); - return -1; + goto bad_request; } if (strlen(key) != QIO_CHANNEL_WEBSOCK_CLIENT_KEY_LEN) { error_setg(errp, "Key length '%zu' was not as expected '%d'", strlen(key), QIO_CHANNEL_WEBSOCK_CLIENT_KEY_LEN); - return -1; + goto bad_request; } if (!g_strrstr(connection, QIO_CHANNEL_WEBSOCK_CONNECTION_UPGRADE)) { error_setg(errp, "No connection upgrade requested '%s'", connection); - return -1; + goto bad_request; } if (!g_str_equal(upgrade, QIO_CHANNEL_WEBSOCK_UPGRADE_WEBSOCKET)) { error_setg(errp, "Incorrect upgrade method '%s'", upgrade); - return -1; + goto bad_request; } - return qio_channel_websock_handshake_send_response(ioc, key, errp); + qio_channel_websock_handshake_send_res_ok(ioc, key, errp); + return; + + bad_request: + qio_channel_websock_handshake_send_res_err( + ioc, QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_BAD_REQUEST); } static int qio_channel_websock_handshake_read(QIOChannelWebsock *ioc, @@ -393,20 +466,20 @@ static int qio_channel_websock_handshake_read(QIOChannelWebsock *ioc, QIO_CHANNEL_WEBSOCK_HANDSHAKE_END); if (!handshake_end) { if (ioc->encinput.offset >= 4096) { + qio_channel_websock_handshake_send_res_err( + ioc, QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_TOO_LARGE); error_setg(errp, "End of headers not found in first 4096 bytes"); - return -1; + return 1; } else { return 0; } } *handshake_end = '\0'; - if (qio_channel_websock_handshake_process(ioc, - (char *)ioc->encinput.buffer, - errp) < 0) { - return -1; - } + qio_channel_websock_handshake_process(ioc, + (char *)ioc->encinput.buffer, + errp); buffer_advance(&ioc->encinput, handshake_end - (char *)ioc->encinput.buffer + @@ -438,8 +511,15 @@ static gboolean qio_channel_websock_handshake_send(QIOChannel *ioc, buffer_advance(&wioc->encoutput, ret); if (wioc->encoutput.offset == 0) { - trace_qio_channel_websock_handshake_complete(ioc); - qio_task_complete(task); + if (wioc->io_err) { + trace_qio_channel_websock_handshake_fail(ioc); + qio_task_set_error(task, wioc->io_err); + wioc->io_err = NULL; + qio_task_complete(task); + } else { + trace_qio_channel_websock_handshake_complete(ioc); + qio_task_complete(task); + } return FALSE; } trace_qio_channel_websock_handshake_pending(ioc, G_IO_OUT); @@ -458,6 +538,11 @@ static gboolean qio_channel_websock_handshake_io(QIOChannel *ioc, ret = qio_channel_websock_handshake_read(wioc, &err); if (ret < 0) { + /* + * We only take this path on a fatal I/O error reading from + * client connection, as most of the time we have an + * HTTP 4xx err response to send instead + */ trace_qio_channel_websock_handshake_fail(ioc); qio_task_set_error(task, err); qio_task_complete(task); @@ -469,6 +554,10 @@ static gboolean qio_channel_websock_handshake_io(QIOChannel *ioc, return TRUE; } + if (err) { + error_propagate(&wioc->io_err, err); + } + trace_qio_channel_websock_handshake_reply(ioc); qio_channel_add_watch( wioc->master, -- 2.13.5 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH v1 1/2] io: send proper HTTP response for websocket errors 2017-09-06 10:40 ` [Qemu-devel] [PATCH v1 1/2] io: send proper HTTP response for websocket errors Daniel P. Berrange @ 2017-09-06 18:06 ` Philippe Mathieu-Daudé 2017-09-07 9:13 ` Daniel P. Berrange 0 siblings, 1 reply; 6+ messages in thread From: Philippe Mathieu-Daudé @ 2017-09-06 18:06 UTC (permalink / raw) To: Daniel P. Berrange, qemu-devel; +Cc: Brian Rak Hi Daniel, On 09/06/2017 07:40 AM, Daniel P. Berrange wrote: > When any error occurs while processing the websockets handshake, > QEMU just terminates the connection abruptly. This is in violation > of the HTTP specs and does not help the client understand what they > did wrong. This is particularly bad when the client gives the wrong > path, as a "404 Not Found" would be very helpful. > > Refactor the handshake code so that it always sends a response to > the client unless there was an I/O error. > > Fixes bug: #1715186 > > Signed-off-by: Daniel P. Berrange <berrange@redhat.com> > --- > io/channel-websock.c | 179 ++++++++++++++++++++++++++++++++++++++------------- > 1 file changed, 134 insertions(+), 45 deletions(-) > > diff --git a/io/channel-websock.c b/io/channel-websock.c > index 5a3badbec2..b9cc5a1371 100644 > --- a/io/channel-websock.c > +++ b/io/channel-websock.c > @@ -44,13 +44,39 @@ > #define QIO_CHANNEL_WEBSOCK_CONNECTION_UPGRADE "Upgrade" > #define QIO_CHANNEL_WEBSOCK_UPGRADE_WEBSOCKET "websocket" > > -#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RESPONSE \ > +#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON \ > + "Server: QEMU VNC\r\n" \ > + "Date: %s\r\n" and "Sec-WebSocket-Version: " \ QIO_CHANNEL_WEBSOCK_SUPPORTED_VERSION "\r\n" \ or what about: #define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON(conn) \ "Server: QEMU VNC\r\n" \ "Date: %s\r\n" \ "Connection: " conn "\r\n" \ "Sec-WebSocket-Version: " \ QIO_CHANNEL_WEBSOCK_SUPPORTED_VERSION "\r\n" > + > +#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_OK \ > "HTTP/1.1 101 Switching Protocols\r\n" \ > + QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON \ > "Upgrade: websocket\r\n" \ > "Connection: Upgrade\r\n" \ > "Sec-WebSocket-Accept: %s\r\n" \ > "Sec-WebSocket-Protocol: binary\r\n" \ > "\r\n" > +#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_NOT_FOUND \ > + "HTTP/1.1 404 Not Found\r\n" \ > + QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON \ > + "Connection: close\r\n" \ > + "\r\n" > +#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_BAD_REQUEST \ > + "HTTP/1.1 400 Bad Request\r\n" \ > + QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON \ > + "Connection: close\r\n" \ > + "Sec-WebSocket-Version: 13\r\n" \ drop > + "\r\n" or with previous macro: #define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_BAD_REQUEST \ "HTTP/1.1 400 Bad Request\r\n" \ QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON("close") \ "\r\n" > +#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_SERVER_ERR \ > + "HTTP/1.1 500 Internal Server Error\r\n" \ > + QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON \ > + "Connection: close\r\n" \ > + "\r\n" > +#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_TOO_LARGE \ > + "HTTP/1.1 403 Request Entity Too Large\r\n" \ > + QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON \ > + "Connection: close\r\n" \ > + "\r\n" > #define QIO_CHANNEL_WEBSOCK_HANDSHAKE_DELIM "\r\n" > #define QIO_CHANNEL_WEBSOCK_HANDSHAKE_END "\r\n\r\n" > #define QIO_CHANNEL_WEBSOCK_SUPPORTED_VERSION "13" > @@ -123,8 +149,43 @@ enum { > QIO_CHANNEL_WEBSOCK_OPCODE_PONG = 0xA > }; > > +static void qio_channel_websock_handshake_send_res(QIOChannelWebsock *ioc, > + const char *resmsg, > + ...) > +{ > + va_list vargs; > + char *response = NULL; NULL not needed > + size_t responselen; > + > + va_start(vargs, resmsg); > + response = g_strdup_vprintf(resmsg, vargs); > + responselen = strlen(response); > + buffer_reserve(&ioc->encoutput, responselen); > + buffer_append(&ioc->encoutput, response, responselen); > + va_end(vargs); > +} > + > +static gchar *qio_channel_websock_date_str(void) > +{ > + GTimeZone *utc = g_time_zone_new_utc(); > + GDateTime *now = g_date_time_new_now(utc); > + gchar *ret = g_date_time_format(now, "%a, %d %b %Y %H:%M:%S GMT"); assert(ret); > + g_date_time_unref(now); > + g_time_zone_unref(utc); > + return ret; > +} > + > +static void qio_channel_websock_handshake_send_res_err(QIOChannelWebsock *ioc, > + const char *resdata) > +{ > + char *date = qio_channel_websock_date_str(); > + qio_channel_websock_handshake_send_res(ioc, resdata, date); > + g_free(date); > +} > + > static size_t > -qio_channel_websock_extract_headers(char *buffer, > +qio_channel_websock_extract_headers(QIOChannelWebsock *ioc, > + char *buffer, > QIOChannelWebsockHTTPHeader *hdrs, > size_t nhdrsalloc, > Error **errp) > @@ -145,7 +206,7 @@ qio_channel_websock_extract_headers(char *buffer, > nl = strstr(buffer, QIO_CHANNEL_WEBSOCK_HANDSHAKE_DELIM); > if (!nl) { > error_setg(errp, "Missing HTTP header delimiter"); > - return 0; > + goto bad_request; > } > *nl = '\0'; > > @@ -158,18 +219,20 @@ qio_channel_websock_extract_headers(char *buffer, > > if (!g_str_equal(buffer, QIO_CHANNEL_WEBSOCK_HTTP_METHOD)) { > error_setg(errp, "Unsupported HTTP method %s", buffer); > - return 0; > + goto bad_request; > } > > buffer = tmp + 1; > tmp = strchr(buffer, ' '); > if (!tmp) { > error_setg(errp, "Missing HTTP version delimiter"); > - return 0; > + goto bad_request; > } > *tmp = '\0'; > > if (!g_str_equal(buffer, QIO_CHANNEL_WEBSOCK_HTTP_PATH)) { > + qio_channel_websock_handshake_send_res_err( > + ioc, QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_NOT_FOUND); > error_setg(errp, "Unexpected HTTP path %s", buffer); > return 0; > } > @@ -178,7 +241,7 @@ qio_channel_websock_extract_headers(char *buffer, > > if (!g_str_equal(buffer, QIO_CHANNEL_WEBSOCK_HTTP_VERSION)) { > error_setg(errp, "Unsupported HTTP version %s", buffer); > - return 0; > + goto bad_request; > } > > buffer = nl + strlen(QIO_CHANNEL_WEBSOCK_HANDSHAKE_DELIM); > @@ -203,7 +266,7 @@ qio_channel_websock_extract_headers(char *buffer, > sep = strchr(buffer, ':'); > if (!sep) { > error_setg(errp, "Malformed HTTP header"); > - return 0; > + goto bad_request; > } > *sep = '\0'; > sep++; > @@ -213,7 +276,7 @@ qio_channel_websock_extract_headers(char *buffer, > > if (nhdrs >= nhdrsalloc) { > error_setg(errp, "Too many HTTP headers"); > - return 0; > + goto bad_request; > } > > hdr = &hdrs[nhdrs++]; > @@ -231,6 +294,11 @@ qio_channel_websock_extract_headers(char *buffer, > } while (nl != NULL); > > return nhdrs; > + > + bad_request: > + qio_channel_websock_handshake_send_res_err( > + ioc, QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_BAD_REQUEST); > + return 0; > } > > static const char * > @@ -250,14 +318,14 @@ qio_channel_websock_find_header(QIOChannelWebsockHTTPHeader *hdrs, > } > > > -static int qio_channel_websock_handshake_send_response(QIOChannelWebsock *ioc, > - const char *key, > - Error **errp) > +static void qio_channel_websock_handshake_send_res_ok(QIOChannelWebsock *ioc, > + const char *key, > + Error **errp) > { > char combined_key[QIO_CHANNEL_WEBSOCK_CLIENT_KEY_LEN + > QIO_CHANNEL_WEBSOCK_GUID_LEN + 1]; > - char *accept = NULL, *response = NULL; > - size_t responselen; > + char *accept = NULL; > + char *date = qio_channel_websock_date_str(); > > g_strlcpy(combined_key, key, QIO_CHANNEL_WEBSOCK_CLIENT_KEY_LEN + 1); > g_strlcat(combined_key, QIO_CHANNEL_WEBSOCK_GUID, > @@ -271,105 +339,110 @@ static int qio_channel_websock_handshake_send_response(QIOChannelWebsock *ioc, > QIO_CHANNEL_WEBSOCK_GUID_LEN, > &accept, > errp) < 0) { > - return -1; > + qio_channel_websock_handshake_send_res_err( > + ioc, QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_SERVER_ERR); > + return; > } > > - response = g_strdup_printf(QIO_CHANNEL_WEBSOCK_HANDSHAKE_RESPONSE, accept); > - responselen = strlen(response); > - buffer_reserve(&ioc->encoutput, responselen); > - buffer_append(&ioc->encoutput, response, responselen); > + qio_channel_websock_handshake_send_res( > + ioc, QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_OK, date, accept); > > + g_free(date); > g_free(accept); > - g_free(response); > > - return 0; > + return; drop > } > > -static int qio_channel_websock_handshake_process(QIOChannelWebsock *ioc, > - char *buffer, > - Error **errp) > +static void qio_channel_websock_handshake_process(QIOChannelWebsock *ioc, > + char *buffer, > + Error **errp) > { > QIOChannelWebsockHTTPHeader hdrs[32]; > size_t nhdrs = G_N_ELEMENTS(hdrs); > const char *protocols = NULL, *version = NULL, *key = NULL, > *host = NULL, *connection = NULL, *upgrade = NULL; > > - nhdrs = qio_channel_websock_extract_headers(buffer, hdrs, nhdrs, errp); > + nhdrs = qio_channel_websock_extract_headers(ioc, buffer, hdrs, nhdrs, errp); > if (!nhdrs) { > - return -1; > + return; > } > > protocols = qio_channel_websock_find_header( > hdrs, nhdrs, QIO_CHANNEL_WEBSOCK_HEADER_PROTOCOL); > if (!protocols) { > error_setg(errp, "Missing websocket protocol header data"); > - return -1; > + goto bad_request; > } > > version = qio_channel_websock_find_header( > hdrs, nhdrs, QIO_CHANNEL_WEBSOCK_HEADER_VERSION); > if (!version) { > error_setg(errp, "Missing websocket version header data"); > - return -1; > + goto bad_request; > } > > key = qio_channel_websock_find_header( > hdrs, nhdrs, QIO_CHANNEL_WEBSOCK_HEADER_KEY); > if (!key) { > error_setg(errp, "Missing websocket key header data"); > - return -1; > + goto bad_request; > } > > host = qio_channel_websock_find_header( > hdrs, nhdrs, QIO_CHANNEL_WEBSOCK_HEADER_HOST); > if (!host) { > error_setg(errp, "Missing websocket host header data"); > - return -1; > + goto bad_request; > } > > connection = qio_channel_websock_find_header( > hdrs, nhdrs, QIO_CHANNEL_WEBSOCK_HEADER_CONNECTION); > if (!connection) { > error_setg(errp, "Missing websocket connection header data"); > - return -1; > + goto bad_request; > } > > upgrade = qio_channel_websock_find_header( > hdrs, nhdrs, QIO_CHANNEL_WEBSOCK_HEADER_UPGRADE); > if (!upgrade) { > error_setg(errp, "Missing websocket upgrade header data"); > - return -1; > + goto bad_request; > } > > if (!g_strrstr(protocols, QIO_CHANNEL_WEBSOCK_PROTOCOL_BINARY)) { > error_setg(errp, "No '%s' protocol is supported by client '%s'", > QIO_CHANNEL_WEBSOCK_PROTOCOL_BINARY, protocols); > - return -1; > + goto bad_request; > } > > if (!g_str_equal(version, QIO_CHANNEL_WEBSOCK_SUPPORTED_VERSION)) { > error_setg(errp, "Version '%s' is not supported by client '%s'", > QIO_CHANNEL_WEBSOCK_SUPPORTED_VERSION, version); > - return -1; > + goto bad_request; > } > > if (strlen(key) != QIO_CHANNEL_WEBSOCK_CLIENT_KEY_LEN) { > error_setg(errp, "Key length '%zu' was not as expected '%d'", > strlen(key), QIO_CHANNEL_WEBSOCK_CLIENT_KEY_LEN); > - return -1; > + goto bad_request; > } > > if (!g_strrstr(connection, QIO_CHANNEL_WEBSOCK_CONNECTION_UPGRADE)) { > error_setg(errp, "No connection upgrade requested '%s'", connection); > - return -1; > + goto bad_request; > } > > if (!g_str_equal(upgrade, QIO_CHANNEL_WEBSOCK_UPGRADE_WEBSOCKET)) { > error_setg(errp, "Incorrect upgrade method '%s'", upgrade); > - return -1; > + goto bad_request; > } > > - return qio_channel_websock_handshake_send_response(ioc, key, errp); > + qio_channel_websock_handshake_send_res_ok(ioc, key, errp); > + return; > + > + bad_request: > + qio_channel_websock_handshake_send_res_err( > + ioc, QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_BAD_REQUEST); > } > > static int qio_channel_websock_handshake_read(QIOChannelWebsock *ioc, > @@ -393,20 +466,20 @@ static int qio_channel_websock_handshake_read(QIOChannelWebsock *ioc, > QIO_CHANNEL_WEBSOCK_HANDSHAKE_END); > if (!handshake_end) { > if (ioc->encinput.offset >= 4096) { > + qio_channel_websock_handshake_send_res_err( > + ioc, QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_TOO_LARGE); > error_setg(errp, > "End of headers not found in first 4096 bytes"); > - return -1; > + return 1; > } else { > return 0; > } > } > *handshake_end = '\0'; > > - if (qio_channel_websock_handshake_process(ioc, > - (char *)ioc->encinput.buffer, > - errp) < 0) { > - return -1; > - } > + qio_channel_websock_handshake_process(ioc, > + (char *)ioc->encinput.buffer, > + errp); > > buffer_advance(&ioc->encinput, > handshake_end - (char *)ioc->encinput.buffer + > @@ -438,8 +511,15 @@ static gboolean qio_channel_websock_handshake_send(QIOChannel *ioc, > > buffer_advance(&wioc->encoutput, ret); > if (wioc->encoutput.offset == 0) { > - trace_qio_channel_websock_handshake_complete(ioc); > - qio_task_complete(task); > + if (wioc->io_err) { > + trace_qio_channel_websock_handshake_fail(ioc); > + qio_task_set_error(task, wioc->io_err); > + wioc->io_err = NULL; > + qio_task_complete(task); > + } else { > + trace_qio_channel_websock_handshake_complete(ioc); > + qio_task_complete(task); > + } > return FALSE; > } > trace_qio_channel_websock_handshake_pending(ioc, G_IO_OUT); > @@ -458,6 +538,11 @@ static gboolean qio_channel_websock_handshake_io(QIOChannel *ioc, > > ret = qio_channel_websock_handshake_read(wioc, &err); > if (ret < 0) { > + /* > + * We only take this path on a fatal I/O error reading from > + * client connection, as most of the time we have an > + * HTTP 4xx err response to send instead > + */ > trace_qio_channel_websock_handshake_fail(ioc); > qio_task_set_error(task, err); > qio_task_complete(task); > @@ -469,6 +554,10 @@ static gboolean qio_channel_websock_handshake_io(QIOChannel *ioc, > return TRUE; > } > > + if (err) { > + error_propagate(&wioc->io_err, err); > + } > + > trace_qio_channel_websock_handshake_reply(ioc); > qio_channel_add_watch( > wioc->master, > looks good :) Regards, Phil. ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH v1 1/2] io: send proper HTTP response for websocket errors 2017-09-06 18:06 ` Philippe Mathieu-Daudé @ 2017-09-07 9:13 ` Daniel P. Berrange 0 siblings, 0 replies; 6+ messages in thread From: Daniel P. Berrange @ 2017-09-07 9:13 UTC (permalink / raw) To: Philippe Mathieu-Daudé; +Cc: qemu-devel, Brian Rak On Wed, Sep 06, 2017 at 03:06:03PM -0300, Philippe Mathieu-Daudé wrote: > Hi Daniel, > > On 09/06/2017 07:40 AM, Daniel P. Berrange wrote: > > When any error occurs while processing the websockets handshake, > > QEMU just terminates the connection abruptly. This is in violation > > of the HTTP specs and does not help the client understand what they > > did wrong. This is particularly bad when the client gives the wrong > > path, as a "404 Not Found" would be very helpful. > > > > Refactor the handshake code so that it always sends a response to > > the client unless there was an I/O error. > > > > Fixes bug: #1715186 > > > > Signed-off-by: Daniel P. Berrange <berrange@redhat.com> > > --- > > io/channel-websock.c | 179 ++++++++++++++++++++++++++++++++++++++------------- > > 1 file changed, 134 insertions(+), 45 deletions(-) > > > > diff --git a/io/channel-websock.c b/io/channel-websock.c > > index 5a3badbec2..b9cc5a1371 100644 > > --- a/io/channel-websock.c > > +++ b/io/channel-websock.c > > @@ -44,13 +44,39 @@ > > #define QIO_CHANNEL_WEBSOCK_CONNECTION_UPGRADE "Upgrade" > > #define QIO_CHANNEL_WEBSOCK_UPGRADE_WEBSOCKET "websocket" > > -#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RESPONSE \ > > +#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON \ > > + "Server: QEMU VNC\r\n" \ > > + "Date: %s\r\n" > > and > "Sec-WebSocket-Version: " \ > QIO_CHANNEL_WEBSOCK_SUPPORTED_VERSION "\r\n" \ This header is only supposed to be set in error responses, not in the 101 response. > or what about: > > #define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON(conn) \ > "Server: QEMU VNC\r\n" \ > "Date: %s\r\n" \ > "Connection: " conn "\r\n" \ > "Sec-WebSocket-Version: " \ > QIO_CHANNEL_WEBSOCK_SUPPORTED_VERSION "\r\n" I'm not a fan of parameterizing this - I think it is clearer to see the full connection header inline below. > > + > > +#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_OK \ > > "HTTP/1.1 101 Switching Protocols\r\n" \ > > + QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON \ > > "Upgrade: websocket\r\n" \ > > "Connection: Upgrade\r\n" \ > > "Sec-WebSocket-Accept: %s\r\n" \ > > "Sec-WebSocket-Protocol: binary\r\n" \ > > "\r\n" > > +#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_NOT_FOUND \ > > + "HTTP/1.1 404 Not Found\r\n" \ > > + QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON \ > > + "Connection: close\r\n" \ > > + "\r\n" > > +#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_BAD_REQUEST \ > > + "HTTP/1.1 400 Bad Request\r\n" \ > > + QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON \ > > + "Connection: close\r\n" \ > > + "Sec-WebSocket-Version: 13\r\n" \ > > drop > > > + "\r\n" > > or with previous macro: > > #define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_BAD_REQUEST \ > "HTTP/1.1 400 Bad Request\r\n" \ > QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON("close") \ > "\r\n" > > > +#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_SERVER_ERR \ > > + "HTTP/1.1 500 Internal Server Error\r\n" \ > > + QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON \ > > + "Connection: close\r\n" \ > > + "\r\n" > > +#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_TOO_LARGE \ > > + "HTTP/1.1 403 Request Entity Too Large\r\n" \ > > + QIO_CHANNEL_WEBSOCK_HANDSHAKE_RES_COMMON \ > > + "Connection: close\r\n" \ > > + "\r\n" > > #define QIO_CHANNEL_WEBSOCK_HANDSHAKE_DELIM "\r\n" > > #define QIO_CHANNEL_WEBSOCK_HANDSHAKE_END "\r\n\r\n" > > #define QIO_CHANNEL_WEBSOCK_SUPPORTED_VERSION "13" Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :| ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Qemu-devel] [PATCH v1 2/2] io: include full error message in websocket handshake trace 2017-09-06 10:40 [Qemu-devel] [PATCH v1 0/2] Improve websockets server error reporting Daniel P. Berrange 2017-09-06 10:40 ` [Qemu-devel] [PATCH v1 1/2] io: send proper HTTP response for websocket errors Daniel P. Berrange @ 2017-09-06 10:40 ` Daniel P. Berrange 2017-09-06 18:06 ` Philippe Mathieu-Daudé 1 sibling, 1 reply; 6+ messages in thread From: Daniel P. Berrange @ 2017-09-06 10:40 UTC (permalink / raw) To: qemu-devel; +Cc: Brian Rak, Daniel P. Berrange When the websocket handshake fails it is useful to log the real error message via the trace points for debugging purposes. Fixes bug: #1715186 Signed-off-by: Daniel P. Berrange <berrange@redhat.com> --- io/channel-websock.c | 7 ++++--- io/trace-events | 2 +- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/io/channel-websock.c b/io/channel-websock.c index b9cc5a1371..463c04b0aa 100644 --- a/io/channel-websock.c +++ b/io/channel-websock.c @@ -503,7 +503,7 @@ static gboolean qio_channel_websock_handshake_send(QIOChannel *ioc, &err); if (ret < 0) { - trace_qio_channel_websock_handshake_fail(ioc); + trace_qio_channel_websock_handshake_fail(ioc, error_get_pretty(err)); qio_task_set_error(task, err); qio_task_complete(task); return FALSE; @@ -512,7 +512,8 @@ static gboolean qio_channel_websock_handshake_send(QIOChannel *ioc, buffer_advance(&wioc->encoutput, ret); if (wioc->encoutput.offset == 0) { if (wioc->io_err) { - trace_qio_channel_websock_handshake_fail(ioc); + trace_qio_channel_websock_handshake_fail( + ioc, error_get_pretty(wioc->io_err)); qio_task_set_error(task, wioc->io_err); wioc->io_err = NULL; qio_task_complete(task); @@ -543,7 +544,7 @@ static gboolean qio_channel_websock_handshake_io(QIOChannel *ioc, * client connection, as most of the time we have an * HTTP 4xx err response to send instead */ - trace_qio_channel_websock_handshake_fail(ioc); + trace_qio_channel_websock_handshake_fail(ioc, error_get_pretty(err)); qio_task_set_error(task, err); qio_task_complete(task); return FALSE; diff --git a/io/trace-events b/io/trace-events index 3d233698d0..6459f71f5b 100644 --- a/io/trace-events +++ b/io/trace-events @@ -46,7 +46,7 @@ qio_channel_websock_new_server(void *ioc, void *master) "Websock new client ioc= qio_channel_websock_handshake_start(void *ioc) "Websock handshake start ioc=%p" qio_channel_websock_handshake_pending(void *ioc, int status) "Websock handshake pending ioc=%p status=%d" qio_channel_websock_handshake_reply(void *ioc) "Websock handshake reply ioc=%p" -qio_channel_websock_handshake_fail(void *ioc) "Websock handshake fail ioc=%p" +qio_channel_websock_handshake_fail(void *ioc, const char *msg) "Websock handshake fail ioc=%p err=%s" qio_channel_websock_handshake_complete(void *ioc) "Websock handshake complete ioc=%p" # io/channel-command.c -- 2.13.5 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH v1 2/2] io: include full error message in websocket handshake trace 2017-09-06 10:40 ` [Qemu-devel] [PATCH v1 2/2] io: include full error message in websocket handshake trace Daniel P. Berrange @ 2017-09-06 18:06 ` Philippe Mathieu-Daudé 0 siblings, 0 replies; 6+ messages in thread From: Philippe Mathieu-Daudé @ 2017-09-06 18:06 UTC (permalink / raw) To: Daniel P. Berrange, qemu-devel; +Cc: Brian Rak On 09/06/2017 07:40 AM, Daniel P. Berrange wrote: > When the websocket handshake fails it is useful to log the real > error message via the trace points for debugging purposes. > > Fixes bug: #1715186 > > Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> > --- > io/channel-websock.c | 7 ++++--- > io/trace-events | 2 +- > 2 files changed, 5 insertions(+), 4 deletions(-) > > diff --git a/io/channel-websock.c b/io/channel-websock.c > index b9cc5a1371..463c04b0aa 100644 > --- a/io/channel-websock.c > +++ b/io/channel-websock.c > @@ -503,7 +503,7 @@ static gboolean qio_channel_websock_handshake_send(QIOChannel *ioc, > &err); > > if (ret < 0) { > - trace_qio_channel_websock_handshake_fail(ioc); > + trace_qio_channel_websock_handshake_fail(ioc, error_get_pretty(err)); > qio_task_set_error(task, err); > qio_task_complete(task); > return FALSE; > @@ -512,7 +512,8 @@ static gboolean qio_channel_websock_handshake_send(QIOChannel *ioc, > buffer_advance(&wioc->encoutput, ret); > if (wioc->encoutput.offset == 0) { > if (wioc->io_err) { > - trace_qio_channel_websock_handshake_fail(ioc); > + trace_qio_channel_websock_handshake_fail( > + ioc, error_get_pretty(wioc->io_err)); > qio_task_set_error(task, wioc->io_err); > wioc->io_err = NULL; > qio_task_complete(task); > @@ -543,7 +544,7 @@ static gboolean qio_channel_websock_handshake_io(QIOChannel *ioc, > * client connection, as most of the time we have an > * HTTP 4xx err response to send instead > */ > - trace_qio_channel_websock_handshake_fail(ioc); > + trace_qio_channel_websock_handshake_fail(ioc, error_get_pretty(err)); > qio_task_set_error(task, err); > qio_task_complete(task); > return FALSE; > diff --git a/io/trace-events b/io/trace-events > index 3d233698d0..6459f71f5b 100644 > --- a/io/trace-events > +++ b/io/trace-events > @@ -46,7 +46,7 @@ qio_channel_websock_new_server(void *ioc, void *master) "Websock new client ioc= > qio_channel_websock_handshake_start(void *ioc) "Websock handshake start ioc=%p" > qio_channel_websock_handshake_pending(void *ioc, int status) "Websock handshake pending ioc=%p status=%d" > qio_channel_websock_handshake_reply(void *ioc) "Websock handshake reply ioc=%p" > -qio_channel_websock_handshake_fail(void *ioc) "Websock handshake fail ioc=%p" > +qio_channel_websock_handshake_fail(void *ioc, const char *msg) "Websock handshake fail ioc=%p err=%s" > qio_channel_websock_handshake_complete(void *ioc) "Websock handshake complete ioc=%p" > > # io/channel-command.c > ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-09-07 9:13 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2017-09-06 10:40 [Qemu-devel] [PATCH v1 0/2] Improve websockets server error reporting Daniel P. Berrange 2017-09-06 10:40 ` [Qemu-devel] [PATCH v1 1/2] io: send proper HTTP response for websocket errors Daniel P. Berrange 2017-09-06 18:06 ` Philippe Mathieu-Daudé 2017-09-07 9:13 ` Daniel P. Berrange 2017-09-06 10:40 ` [Qemu-devel] [PATCH v1 2/2] io: include full error message in websocket handshake trace Daniel P. Berrange 2017-09-06 18:06 ` Philippe Mathieu-Daudé
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