TSVCONNPR...LE/DISABLE(3ts)

💖 TSVConnProtocolEnable/Disable — the TSVConnProtocol API function ✨

okay bestie, so this is the page for TSVConnProtocolEnable and TSVConnProtocolDisable from Apache Traffic Server 🎀 — two little functions that let you boss around which protocols get advertised during TLS protocol negotiation. no cap.

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🌸 SYNOPSIS 🌸

#include <ts/ts.h>

TSReturnCode TSVConnProtocolEnable(TSVConn vconn, const char *protocol)

TSReturnCode TSVConnProtocolDisable(TSVConn vconn, const char *protocol)

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🦋 DESCRIPTION 🦋

so, TSVConnProtocolEnable() turns on the protocol you pass in as protocol, so it gets advertised in the TLS protocol negotiation. it's giving "yes bestie, we support this, put it on the menu" 💅

and TSVConnProtocolDisable() is the reverse — it takes the protocol named by protocol right out of the TLS protocol negotiation. gone. not invited to the party. 💀

🫶 IMPORTANT VIBE CHECK: for these calls to actually do anything, you have to make them from the early TLS negotiation hooks — like TS_SSL_CLIENT_HELLO_HOOK or TS_SSL_SERVERNAME_HOOK. do it too late and it's giving "too late, the door's already closed" 😭 timing is literally everything here.

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⭐ EXAMPLES ⭐

this next bit is excerpted from example/plugins/c-api/disable_http2/disable_http2.cc in the Traffic Server source distribution 📂. it shows how you'd use TSVConnProtocolDisable() inside a plugin called from the TS_SSL_SERVERNAME_HOOK. look at her go 🔥

int
CB_SNI(TSCont contp, TSEvent, void *cb_data)
{
  auto vc                  = static_cast<TSVConn>(cb_data);
  TSSslConnection ssl_conn = TSVConnSslConnectionGet(vc);
  auto *ssl                = reinterpret_cast<SSL *>(ssl_conn);
  char const *sni          = SSL_get_servername(ssl, TLSEXT_NAMETYPE_host_name);
  if (sni) {
    if (Domains.find(sni) != Domains.end()) {
      TSDebug(PLUGIN_NAME, "Disable H2 for SNI=%s", sni);
      TSVConnProtocolDisable(vc, TS_ALPN_PROTOCOL_HTTP_2_0);
    }
  }

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👑 COPYRIGHT 👑

2026, dev@trafficserver.apache.org 💜

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and that's the whole page, bestie 🧚 — Apache Traffic Server, version 9.2, dated Feb 12, 2026. go forth and negotiate those protocols responsibly. periodt. 💖✨