TSVConnFdCreate - create a TSVConn from a socket

       2025, dev@trafficserver.apache.org

9.2                                               May 22, 2025                              TSVCONNFDCREATE(3ts)

TSVConnFdCreate()  accepts a network socket fd and returns a new TSVConn constructed from the socket. The
       socket descriptor must be an already connected socket. It will be placed into non-blocking mode.

       The  example  below  is excerpted from example/plugins/c-api/intercept/intercept.cc in the Traffic Server
       source distribution. It demonstrates how to use TSVConnFdCreate() to construct a TSVConn from a connected
       socket.

              // the TSHttpTxn pointer.
              VDEBUG("allocated server intercept state istate=%p for txn=%p", istate, cdata.txn);

              // Set up a connection to our real origin, which will be
              // 127.0.0.1:$PORT.
              memset(&addr, 0, sizeof(addr));
              addr.sin.sin_family      = AF_INET;
              addr.sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK); // XXX config option
              addr.sin.sin_port        = htons(PORT);            // XXX config option

              // Normally, we would use TSNetConnect to connect to a secondary service, but to demonstrate
              // the use of TSVConnFdCreate, we do a blocking connect inline. This it not recommended for
              // production plugins, since it might block an event thread for an arbitrary time.
              fd = ::socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
              TSReleaseAssert(fd != -1);

              if (::connect(fd, &addr.sa, sizeof(addr.sin)) == -1) {
                // We failed to connect to the intercepted origin. Abort the
                // server intercept since we cannot handle it.
                VDEBUG("connect failed with %s (%d)", strerror(errno), errno);
                TSVConnAbort(arg.vc, TS_VC_CLOSE_ABORT);

                delete istate;
                TSContDestroy(contp);

                ::close(fd);
                return TS_EVENT_NONE;
              }

              if ((istate->server.vc = TSVConnFdCreate(fd)) == nullptr) {
                VDEBUG("TSVconnFdCreate() failed");
                TSVConnAbort(arg.vc, TS_VC_CLOSE_ABORT);

                delete istate;
                TSContDestroy(contp);

                ::close(fd);
                return TS_EVENT_NONE;
              }

              VDEBUG("binding client vc=%p to %s:%u", istate->client.vc, inet_ntop(AF_INET, &addr.sin.sin_addr, buf, sizeof(buf)),
                     (unsigned)ntohs(addr.sin.sin_port));

              istate->txn       = cdata.txn;
              istate->client.vc = arg.vc;

              // Reset the continuation data to be our intercept state
              // block. We will need this so that we can access both of the
              // VCs at the same time. We need to do this before calling

       TSVConnFdCreate - create a TSVConn from a socket

       On success, the returned  TSVConn  object  owns  the  socket  and  the  caller  must  not  close  it.  If
       TSVConnFdCreate() fails, NULL is returned, the socket is unchanged and the caller must close it.

TSAPI(3ts)

          #include <ts/ts.h>

       TSVConnTSVConnFdCreate(intfd)