initial commit

third_party/libhv/examples/kcptun/smux/smux.cpp

@@ -0,0 +1,79 @@
+#include "smux.h"
+
+#define SMUX_USE_LITTLE_ENDIAN 1
+
+int smux_frame_pack(const smux_frame_t* frame, void* buf, int len) {
+    if (!frame || !buf || !len) return -1;
+    const smux_head_t* head = &(frame->head);
+    unsigned int packlen = smux_package_length(head);
+    // Check is buffer enough
+    if (len < packlen) {
+        return -2;
+    }
+    unsigned char* p = (unsigned char*)buf;
+    *p++ = head->version;
+    *p++ = head->cmd;
+#if SMUX_USE_LITTLE_ENDIAN
+    *p++ =  head->length;
+    *p++ = (head->length >> 8) & 0xFF;
+#else
+    // hton length
+    *p++ = (head->length >> 8) & 0xFF;
+    *p++ =  head->length;
+#endif
+
+    uint32_t sid = head->sid;
+#if SMUX_USE_LITTLE_ENDIAN
+    *p++ =  sid        & 0xFF;
+    *p++ = (sid >>  8) & 0xFF;
+    *p++ = (sid >> 16) & 0xFF;
+    *p++ = (sid >> 24) & 0xFF;
+#else
+    // hton sid
+    *p++ = (sid >> 24) & 0xFF;
+    *p++ = (sid >> 16) & 0xFF;
+    *p++ = (sid >>  8) & 0xFF;
+    *p++ =  sid        & 0xFF;
+#endif
+    // memcpy data
+    if (frame->data && head->length) {
+        memcpy(p, frame->data, frame->head.length);
+    }
+    return packlen;
+}
+
+int smux_frame_unpack(smux_frame_t* frame, const void* buf, int len) {
+    if (!frame || !buf || !len) return -1;
+    if (len < SMUX_HEAD_LENGTH) return -2;
+    smux_head_t* head = &(frame->head);
+    unsigned char* p = (unsigned char*)buf;
+    head->version = *p++;
+    head->cmd = *p++;
+#if SMUX_USE_LITTLE_ENDIAN
+    head->length  = *p++;
+    head->length |= ((uint16_t)*p++) << 8;
+#else
+    // ntoh length
+    head->length  = ((uint16_t)*p++) << 8;
+    head->length |= *p++;
+#endif
+
+#if SMUX_USE_LITTLE_ENDIAN
+    head->sid  = *p++;
+    head->sid |= ((uint32_t)*p++) << 8;
+    head->sid |= ((uint32_t)*p++) << 16;
+    head->sid |= ((uint32_t)*p++) << 24;
+#else
+    // ntoh sid
+    head->sid  = ((uint32_t)*p++) << 24;
+    head->sid |= ((uint32_t)*p++) << 16;
+    head->sid |= ((uint32_t)*p++) << 8;
+    head->sid |= *p++;
+#endif
+    // NOTE: just shadow copy
+    if (len > SMUX_HEAD_LENGTH) {
+        frame->data = (const char*)buf + SMUX_HEAD_LENGTH;
+    }
+    unsigned int packlen = smux_package_length(head);
+    return MIN(len, packlen);
+}