From c68df310b8ed853af0e8cf16cce9953d4d92b8e9 Mon Sep 17 00:00:00 2001
From: Sergey Lyubka <valenok@gmail.com>
Date: Fri, 12 Jul 2013 12:25:25 +0100
Subject: [PATCH] Added mg_websocket_write(), per morgan3d pull request
---
examples/websocket.c | 33 +++++----------------------------
mongoose.c | 42 ++++++++++++++++++++++++++++++++++++++++++
mongoose.h | 22 ++++++++++++++++++++++
3 files changed, 69 insertions(+), 28 deletions(-)
diff --git a/examples/websocket.c b/examples/websocket.c
index 799754cb7..8a6083c1c 100644
--- a/examples/websocket.c
+++ b/examples/websocket.c
@@ -6,10 +6,8 @@
#include "mongoose.h"
static void websocket_ready_handler(struct mg_connection *conn) {
- unsigned char buf[40];
- buf[0] = 0x81;
- buf[1] = snprintf((char *) buf + 2, sizeof(buf) - 2, "%s", "server ready");
- mg_write(conn, buf, 2 + buf[1]);
+ static const char *message = "server ready";
+ mg_websocket_write(conn, WEBSOCKET_OPCODE_TEXT, message, strlen(message));
}
// Arguments:
@@ -18,33 +16,12 @@ static void websocket_ready_handler(struct mg_connection *conn) {
// data, data_len: payload data. Mask, if any, is already applied.
static int websocket_data_handler(struct mg_connection *conn, int flags,
char *data, size_t data_len) {
- unsigned char reply[200];
- size_t i;
-
- (void) flags;
-
- printf("rcv: [%.*s]\n", (int) data_len, data);
-
- // Truncate echoed message, to simplify output code.
- if (data_len > 125) {
- data_len = 125;
- }
-
- // Prepare frame
- reply[0] = 0x81; // text, FIN set
- reply[1] = data_len;
-
- // Copy message from request to reply, applying the mask if required.
- for (i = 0; i < data_len; i++) {
- reply[i + 2] = data[i];
- }
-
- // Echo the message back to the client
- mg_write(conn, reply, 2 + data_len);
+ (void) flags; // Unused
+ mg_websocket_write(conn, WEBSOCKET_OPCODE_TEXT, data, data_len);
// Returning zero means stoping websocket conversation.
// Close the conversation if client has sent us "exit" string.
- return memcmp(reply + 2, "exit", 4);
+ return memcmp(data, "exit", 4);
}
int main(void) {
diff --git a/mongoose.c b/mongoose.c
index 41792be4a..43c963498 100644
--- a/mongoose.c
+++ b/mongoose.c
@@ -4090,6 +4090,48 @@ static void read_websocket(struct mg_connection *conn) {
}
}
+int mg_websocket_write(struct mg_connection* conn, int opcode,
+ const char *data, size_t data_len) {
+ unsigned char *copy;
+ size_t copy_len = 0;
+ int retval = -1;
+
+ if ((copy = (unsigned char *) malloc(data_len + 10)) == NULL) {
+ return -1;
+ }
+
+ copy[0] = 0x80 + (opcode & 0x0f);
+
+ // Frame format: http://tools.ietf.org/html/rfc6455#section-5.2
+ if (data_len < 126) {
+ // Inline 7-bit length field
+ copy[1] = data_len;
+ memcpy(copy + 2, data, data_len);
+ copy_len = 2 + data_len;
+ } else if (data_len <= 0xFFFF) {
+ // 16-bit length field
+ copy[1] = 126;
+ * (uint16_t *) (copy + 2) = htons(data_len);
+ memcpy(copy + 4, data, data_len);
+ copy_len = 4 + data_len;
+ } else {
+ // 64-bit length field
+ copy[1] = 127;
+ * (uint32_t *) (copy + 2) = htonl((uint64_t) data_len >> 32);
+ * (uint32_t *) (copy + 6) = htonl(data_len & 0xffffffff);
+ memcpy(copy + 10, data, data_len);
+ copy_len = 10 + data_len;
+ }
+
+ // Not thread safe
+ if (copy_len > 0) {
+ retval = mg_write(conn, copy, copy_len);
+ }
+ free(copy);
+
+ return retval;
+}
+
static void handle_websocket_request(struct mg_connection *conn) {
const char *version = mg_get_header(conn, "Sec-WebSocket-Version");
if (version == NULL || strcmp(version, "13") != 0) {
diff --git a/mongoose.h b/mongoose.h
index 58e484b08..4cc60f136 100644
--- a/mongoose.h
+++ b/mongoose.h
@@ -208,6 +208,28 @@ struct mg_request_info *mg_get_request_info(struct mg_connection *);
int mg_write(struct mg_connection *, const void *buf, size_t len);
+// Send data to a websocket client wrapped in a websocket frame.
+// It is unsafe to read/write to this connection from another thread.
+// This function is available when mongoose is compiled with -DUSE_WEBSOCKET
+//
+// Return:
+// 0 when the connection has been closed
+// -1 on error
+// >0 number of bytes written on success
+int mg_websocket_write(struct mg_connection* conn, int opcode,
+ const char *data, size_t data_len);
+
+// Opcodes, from http://tools.ietf.org/html/rfc6455
+enum {
+ WEBSOCKET_OPCODE_CONTINUATION = 0x0,
+ WEBSOCKET_OPCODE_TEXT = 0x1,
+ WEBSOCKET_OPCODE_BINARY = 0x2,
+ WEBSOCKET_OPCODE_CONNECTION_CLOSE = 0x8,
+ WEBSOCKET_OPCODE_PING = 0x9,
+ WEBSOCKET_OPCODE_PONG = 0xa
+};
+
+
// Macros for enabling compiler-specific checks for printf-like arguments.
#undef PRINTF_FORMAT_STRING
#if _MSC_VER >= 1400
--
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