---
name: "TSVConnFdCreate"
section: "3ts"
platform: "linux"
package: "trafficserver-dev"
version: "9.2.5+ds-0+deb12u4"
release: "Debian 12 (Bookworm)"
platforms: ["linux"]
url: "https://new.carta.tech/TSVConnFdCreate"
---

# TSVConnFdCreate(3ts)

create a TSVConn from a socket

## NAME

TSVConnFdCreate - create a TSVConn from a socket

## SYNOPSIS

```
#include <ts/ts.h>
```

- ***TSVConn* TSVConnFdCreate(int fd)**

  ## DESCRIPTION

*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.

## RETURN VALUES

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.

## EXAMPLES

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
```

## SEE ALSO

**[TSAPI(3ts)](/TSAPI/3ts.md)**

## COPYRIGHT

2026, dev@trafficserver.apache.org