From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id 19B09385801E for ; Fri, 18 Mar 2022 00:20:29 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 19B09385801E Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-158-DC2XZpSVObWK65LZPRhZFw-1; Thu, 17 Mar 2022 20:20:27 -0400 X-MC-Unique: DC2XZpSVObWK65LZPRhZFw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 4D26085A5BE; Fri, 18 Mar 2022 00:20:27 +0000 (UTC) Received: from greed.delorie.com (ovpn-112-4.rdu2.redhat.com [10.10.112.4]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 390A12156893; Fri, 18 Mar 2022 00:20:27 +0000 (UTC) Received: from greed.delorie.com.redhat.com (localhost [127.0.0.1]) by greed.delorie.com (8.15.2/8.15.2) with ESMTP id 22I0KQn31764709; Thu, 17 Mar 2022 20:20:26 -0400 From: DJ Delorie To: Siddhesh Poyarekar Cc: libc-alpha@sourceware.org Subject: Re: [PATCH 3/3] getaddrinfo: Refactor code for readability In-Reply-To: <20220314173039.1060650-4-siddhesh@sourceware.org> (message from Siddhesh Poyarekar via Libc-alpha on Mon, 14 Mar 2022 23:00:39 +0530) Date: Thu, 17 Mar 2022 20:20:26 -0400 Message-ID: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-14.1 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H5, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_NONE, TXREP, T_SCC_BODY_TEXT_LINE autolearn=unavailable autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 18 Mar 2022 00:20:30 -0000 Siddhesh Poyarekar via Libc-alpha writes: > The close_retry goto jump is confusing and clumsy to read, so refactor > the code a bit to make it easier to follow. LGTM with or without the tweak noted below. Reviewed-by: DJ Delorie > diff --git a/sysdeps/posix/getaddrinfo.c b/sysdeps/posix/getaddrinfo.c > +static bool > +try_connect (int *fdp, int *afp, struct sockaddr_in6 *source_addrp, > + const struct sockaddr *addr, socklen_t addrlen, int family) > +{ > + int fd = *fdp; > + int af = *afp; > + socklen_t sl = sizeof (*source_addrp); > + bool retry = false; > + > + do > + { > + if (fd != -1 && __connect (fd, addr, addrlen) == 0 > + && __getsockname (fd, (struct sockaddr *) source_addrp, &sl) == 0) > + return true; > + else if (errno == EAFNOSUPPORT && af == AF_INET6 && family == AF_INET) > + { > + /* This could mean IPv6 sockets are IPv6-only. */ > + if (fd != -1) > + __close_nocancel_nostatus (fd); > + *afp = af = AF_INET; > + *fdp = fd = __socket (AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, > + IPPROTO_IP); > + retry = true; > + } > + else > + return false; > + } > + while (retry); > + > + __builtin_unreachable (); > +} The do/while loop must follow one of three paths: return true, retry=true, or return false. The builtin_unreachable() agrees. Thus, the whole retry logic is unneeded and can be removed, using a do/while(1) loop instead. I'll OK this as-is though, but if your task is to simplify... then simplify :-) > @@ -2346,7 +2377,6 @@ getaddrinfo (const char *name, const char *service, > if (fd == -1 || (af == AF_INET && q->ai_family == AF_INET6)) > { > if (fd != -1) > - close_retry: Ok. > + if (try_connect (&fd, &af, &results[i].source_addr, q->ai_addr, > + q->ai_addrlen, q->ai_family)) > - socklen_t sl = sizeof (results[i].source_addr); > - if (fd != -1 > - && __connect (fd, q->ai_addr, q->ai_addrlen) == 0 > - && __getsockname (fd, > - (struct sockaddr *) &results[i].source_addr, > - &sl) == 0) Matches moved code, ok. > - results[i].source_addr_len = sl; > + results[i].source_addr_len = sizeof (results[i].source_addr); Ok. > - else if (errno == EAFNOSUPPORT && af == AF_INET6 > - && q->ai_family == AF_INET) > - /* This could mean IPv6 sockets are IPv6-only. */ > - goto close_retry; Matches moved code, ok.