Add irc::sockets::untosa() for creating AF_UNIX sockaddrs.

Also fix an overly long albeit harmless memcpy when creating UNIX
socket listeners. Thanks to @psychon for reporting this.

2 files changed, 20 insertions, 6 deletions

diff --git a/include/socket.h b/include/socket.h
index 47e89070f..e527bc7f5 100644
--- a/include/socket.h
+++ b/include/socket.h
@@ -120,6 +120,13 @@ namespace irc
 		 * @return true if the conversion was successful, false if not.
 		 */
 		CoreExport bool aptosa(const std::string& addr, int port, irc::sockets::sockaddrs& sa);
+
+		/** Convert a UNIX socket path to a binary sockaddr.
+		 * @param path The path to the UNIX socket.
+		 * @param sa The structure to place the result in. Will be zeroed prior to conversion.
+		 * @return True if the conversion was successful; otherwise, false.
+		 */
+		CoreExport bool untosa(const std::string& path, irc::sockets::sockaddrs& sa);
 	}
 }
 
diff --git a/src/socket.cpp b/src/socket.cpp
index 580d3ba49..759bc7272 100644
--- a/src/socket.cpp
+++ b/src/socket.cpp
@@ -100,7 +100,7 @@ int InspIRCd::BindPorts(FailedPortList& failed_ports)
 		{
 			// UNIX socket paths are length limited to less than PATH_MAX.
 			irc::sockets::sockaddrs bindspec;
-			if (path.length() > std::min(ServerInstance->Config->Limits.MaxHost, sizeof(bindspec.un.sun_path)))
+			if (path.length() > std::min(ServerInstance->Config->Limits.MaxHost, sizeof(bindspec.un.sun_path) - 1))
 			{
 				this->Logs->Log("SOCKET", LOG_DEFAULT, "UNIX listener on %s at %s specified a path that is too long!",
 					path.c_str(), tag->getTagLocation().c_str());
@@ -115,11 +115,7 @@ int InspIRCd::BindPorts(FailedPortList& failed_ports)
 				continue;
 			}
 
-			// Create the bindspec manually (aptosa doesn't work with AF_UNIX yet).
-			memset(&bindspec, 0, sizeof(bindspec));
-			bindspec.un.sun_family = AF_UNIX;
-			memcpy(&bindspec.un.sun_path, path.c_str(), sizeof(bindspec.un.sun_path));
-
+			irc::sockets::untosa(path, bindspec);
 			if (!BindPort(tag, bindspec, old_ports))
 				failed_ports.push_back(std::make_pair(bindspec, errno));
 			else
@@ -182,6 +178,17 @@ bool irc::sockets::aptosa(const std::string& addr, int port, irc::sockets::socka
 	return false;
 }
 
+bool irc::sockets::untosa(const std::string& path, irc::sockets::sockaddrs& sa)
+{
+	memset(&sa, 0, sizeof(sa));
+	if (path.length() >= sizeof(sa))
+		return false;
+
+	sa.un.sun_family = AF_UNIX;
+	memcpy(&sa.un.sun_path, path.c_str(), path.length() + 1);
+	return true;
+}
+
 int irc::sockets::sockaddrs::family() const
 {
 	return sa.sa_family;