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Tue, 22 Mar 2022 17:10:21 +0000 X-MC-Relay: Junk X-MailChannels-SenderId: dreamhost|x-authsender|siddhesh@gotplt.org X-MailChannels-Auth-Id: dreamhost X-Whistle-Snatch: 1822e57d178d4ba2_1647969021017_1764118769 X-MC-Loop-Signature: 1647969021017:2514637559 X-MC-Ingress-Time: 1647969021016 Received: from rhbox.redhat.com (unknown [1.186.223.130]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: siddhesh@gotplt.org) by pdx1-sub0-mail-a306.dreamhost.com (Postfix) with ESMTPSA id 4KNHzp4Cg7z1NY; Tue, 22 Mar 2022 10:10:14 -0700 (PDT) To: libc-alpha@sourceware.org Subject: [PATCH v2] getaddrinfo: Refactor code for readability Date: Tue, 22 Mar 2022 22:40:05 +0530 Message-Id: <20220322171005.2566082-1-siddhesh@sourceware.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: References: MIME-Version: 1.0 X-Spam-Status: No, score=-3495.0 required=5.0 tests=BAYES_00, GIT_PATCH_0, JMQ_SPF_NEUTRAL, KAM_DMARC_NONE, KAM_DMARC_STATUS, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_NEUTRAL, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham 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-Patchwork-Original-From: Siddhesh Poyarekar via Libc-alpha From: Siddhesh Poyarekar Reply-To: Siddhesh Poyarekar Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org Sender: "Libc-alpha" The close_retry goto jump is confusing and clumsy to read, so refactor the code a bit to make it easier to follow. Signed-off-by: Siddhesh Poyarekar Reviewed-by: DJ Delorie --- sysdeps/posix/getaddrinfo.c | 45 +++++++++++++++++++++++++++---------- 1 file changed, 33 insertions(+), 12 deletions(-) diff --git a/sysdeps/posix/getaddrinfo.c b/sysdeps/posix/getaddrinfo.c index aa34de6591..bcff909b2f 100644 --- a/sysdeps/posix/getaddrinfo.c +++ b/sysdeps/posix/getaddrinfo.c @@ -2246,6 +2246,36 @@ gaiconf_reload (void) gaiconf_init (); } +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); + + while (true) + { + if (fd != -1 && __connect (fd, addr, addrlen) == 0 + && __getsockname (fd, (struct sockaddr *) source_addrp, &sl) == 0) + return true; + + 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); + continue; + } + + return false; + } + + __builtin_unreachable (); +} int getaddrinfo (const char *name, const char *service, @@ -2436,7 +2466,6 @@ getaddrinfo (const char *name, const char *service, if (fd == -1 || (af == AF_INET && q->ai_family == AF_INET6)) { if (fd != -1) - close_retry: __close_nocancel_nostatus (fd); af = q->ai_family; fd = __socket (af, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_IP); @@ -2448,14 +2477,10 @@ getaddrinfo (const char *name, const char *service, __connect (fd, &sa, sizeof (sa)); } - 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) + if (try_connect (&fd, &af, &results[i].source_addr, q->ai_addr, + q->ai_addrlen, q->ai_family)) { - results[i].source_addr_len = sl; + results[i].source_addr_len = sizeof (results[i].source_addr); results[i].got_source_addr = true; if (in6ai != NULL) @@ -2520,10 +2545,6 @@ getaddrinfo (const char *name, const char *service, results[i].source_addr_len = sizeof (struct sockaddr_in); } } - else if (errno == EAFNOSUPPORT && af == AF_INET6 - && q->ai_family == AF_INET) - /* This could mean IPv6 sockets are IPv6-only. */ - goto close_retry; else /* Just make sure that if we have to process the same address again we do not copy any memory. */