From 771908d313ee9c255adfb5e4fdba4d6797c18409 Mon Sep 17 00:00:00 2001
From: Amos Jeffries <yadij@users.noreply.github.com>
Date: Thu, 7 Mar 2019 13:50:38 +0000
Subject: [PATCH] Bug 4928: Cannot convert non-IPv4 to IPv4 (#379)
... when reaching client_ip_max_connections
The client_ip_max_connections limit is checked before the TCP dst-IP is located for the newly received TCP connection. This leaves Squid unable to fetch the NFMARK or similar
details later on (they do not exist for [::]).
Move client_ip_max_connections test later in the TCP accept process to ensure dst-IP is known when the error is produced.
---
src/comm/TcpAcceptor.cc | 82 ++++++++++++++++++++---------------------
1 file changed, 39 insertions(+), 43 deletions(-)
diff --git a/src/comm/TcpAcceptor.cc b/src/comm/TcpAcceptor.cc
index cae92a7b1e..2109913008 100644
--- a/src/comm/TcpAcceptor.cc
+++ b/src/comm/TcpAcceptor.cc
@@ -282,16 +282,7 @@ Comm::TcpAcceptor::acceptOne()
ConnectionPointer newConnDetails = new Connection();
const Comm::Flag flag = oldAccept(newConnDetails);
- /* Check for errors */
- if (!newConnDetails->isOpen()) {
-
- if (flag == Comm::NOMESSAGE) {
- /* register interest again */
- debugs(5, 5, HERE << "try later: " << conn << " handler Subscription: " << theCallSub);
- SetSelect(conn->fd, COMM_SELECT_READ, doAccept, this, 0);
- return;
- }
-
+ if (flag == Comm::COMM_ERROR) {
// A non-recoverable error; notify the caller */
debugs(5, 5, HERE << "non-recoverable error:" << status() << " handler Subscription: " << theCallSub);
if (intendedForUserConnections())
@@ -301,12 +292,16 @@ Comm::TcpAcceptor::acceptOne()
return;
}
- newConnDetails->nfmark = Ip::Qos::getNfmarkFromConnection(newConnDetails, Ip::Qos::dirAccepted);
+ if (flag == Comm::NOMESSAGE) {
+ /* register interest again */
+ debugs(5, 5, "try later: " << conn << " handler Subscription: " << theCallSub);
+ } else {
+ debugs(5, 5, "Listener: " << conn <<
+ " accepted new connection " << newConnDetails <<
+ " handler Subscription: " << theCallSub);
+ notify(flag, newConnDetails);
+ }
- debugs(5, 5, HERE << "Listener: " << conn <<
- " accepted new connection " << newConnDetails <<
- " handler Subscription: " << theCallSub);
- notify(flag, newConnDetails);
SetSelect(conn->fd, COMM_SELECT_READ, doAccept, this, 0);
}
@@ -346,8 +341,8 @@ Comm::TcpAcceptor::notify(const Comm::Flag flag, const Comm::ConnectionPointer &
*
* \retval Comm::OK success. details parameter filled.
* \retval Comm::NOMESSAGE attempted accept() but nothing useful came in.
- * \retval Comm::COMM_ERROR an outright failure occurred.
* Or this client has too many connections already.
+ * \retval Comm::COMM_ERROR an outright failure occurred.
*/
Comm::Flag
Comm::TcpAcceptor::oldAccept(Comm::ConnectionPointer &details)
@@ -382,15 +377,6 @@ Comm::TcpAcceptor::oldAccept(Comm::ConnectionPointer &details)
details->fd = sock;
details->remote = *gai;
- if ( Config.client_ip_max_connections >= 0) {
- if (clientdbEstablished(details->remote, 0) > Config.client_ip_max_connections) {
- debugs(50, DBG_IMPORTANT, "WARNING: " << details->remote << " attempting more than " << Config.client_ip_max_connections << " connections.");
- Ip::Address::FreeAddr(gai);
- PROF_stop(comm_accept);
- return Comm::COMM_ERROR;
- }
- }
-
// lookup the local-end details of this new connection
Ip::Address::InitAddr(gai);
details->local.setEmpty();
@@ -404,6 +390,34 @@ Comm::TcpAcceptor::oldAccept(Comm::ConnectionPointer &details)
details->local = *gai;
Ip::Address::FreeAddr(gai);
+ // Perform NAT or TPROXY operations to retrieve the real client/dest IP addresses
+ if (conn->flags&(COMM_TRANSPARENT|COMM_INTERCEPTION) && !Ip::Interceptor.Lookup(details, conn)) {
+ debugs(50, DBG_IMPORTANT, "ERROR: NAT/TPROXY lookup failed to locate original IPs on " << details);
+ // Failed.
+ PROF_stop(comm_accept);
+ return Comm::COMM_ERROR;
+ }
+
+#if USE_SQUID_EUI
+ if (Eui::TheConfig.euiLookup) {
+ if (details->remote.isIPv4()) {
+ details->remoteEui48.lookup(details->remote);
+ } else if (details->remote.isIPv6()) {
+ details->remoteEui64.lookup(details->remote);
+ }
+ }
+#endif
+
+ details->nfmark = Ip::Qos::getNfmarkFromConnection(details, Ip::Qos::dirAccepted);
+
+ if (Config.client_ip_max_connections >= 0) {
+ if (clientdbEstablished(details->remote, 0) > Config.client_ip_max_connections) {
+ debugs(50, DBG_IMPORTANT, "WARNING: " << details->remote << " attempting more than " << Config.client_ip_max_connections << " connections.");
+ PROF_stop(comm_accept);
+ return Comm::NOMESSAGE;
+ }
+ }
+
/* fdstat update */
// XXX : these are not all HTTP requests. use a note about type and ip:port details->
// so we end up with a uniform "(HTTP|FTP-data|HTTPS|...) remote-ip:remote-port"
@@ -425,24 +439,6 @@ Comm::TcpAcceptor::oldAccept(Comm::ConnectionPointer &details)
/* IFF the socket is (tproxy) transparent, pass the flag down to allow spoofing */
F->flags.transparent = fd_table[conn->fd].flags.transparent; // XXX: can we remove this line yet?
- // Perform NAT or TPROXY operations to retrieve the real client/dest IP addresses
- if (conn->flags&(COMM_TRANSPARENT|COMM_INTERCEPTION) && !Ip::Interceptor.Lookup(details, conn)) {
- debugs(50, DBG_IMPORTANT, "ERROR: NAT/TPROXY lookup failed to locate original IPs on " << details);
- // Failed.
- PROF_stop(comm_accept);
- return Comm::COMM_ERROR;
- }
-
-#if USE_SQUID_EUI
- if (Eui::TheConfig.euiLookup) {
- if (details->remote.isIPv4()) {
- details->remoteEui48.lookup(details->remote);
- } else if (details->remote.isIPv6()) {
- details->remoteEui64.lookup(details->remote);
- }
- }
-#endif
-
PROF_stop(comm_accept);
return Comm::OK;
}