From bae35c080ecad74d003339958db6a0d96b2e64a0 Mon Sep 17 00:00:00 2001 From: des Date: Wed, 14 Dec 2016 14:20:32 +0000 Subject: MFH (r308996, r309051, r309738): refactor, avoid repeating DNS requests --- lib/libfetch/common.c | 173 +++++++++++++++++++++++++++++++++++--------------- lib/libfetch/common.h | 1 + lib/libfetch/ftp.c | 4 +- 3 files changed, 124 insertions(+), 54 deletions(-) (limited to 'lib') diff --git a/lib/libfetch/common.c b/lib/libfetch/common.c index 1536ece..4145314 100644 --- a/lib/libfetch/common.c +++ b/lib/libfetch/common.c @@ -1,5 +1,5 @@ /*- - * Copyright (c) 1998-2014 Dag-Erling Smørgrav + * Copyright (c) 1998-2016 Dag-Erling Smørgrav * Copyright (c) 2013 Michael Gmelin * All rights reserved. * @@ -241,27 +241,79 @@ fetch_ref(conn_t *conn) /* + * Resolve an address + */ +struct addrinfo * +fetch_resolve(const char *addr, int port, int af) +{ + char hbuf[256], sbuf[8]; + struct addrinfo hints, *res; + const char *sep, *host, *service; + int err, len; + + /* split address if necessary */ + err = EAI_SYSTEM; + if ((sep = strchr(addr, ':')) != NULL) { + len = snprintf(hbuf, sizeof(hbuf), + "%.*s", (int)(sep - addr), addr); + if (len < 0) + return (NULL); + if (len >= (int)sizeof(hbuf)) { + errno = ENAMETOOLONG; + fetch_syserr(); + return (NULL); + } + host = hbuf; + service = sep + 1; + } else if (port != 0) { + if (port < 1 || port > 65535) { + errno = EINVAL; + fetch_syserr(); + return (NULL); + } + if (snprintf(sbuf, sizeof(sbuf), "%d", port) < 0) { + fetch_syserr(); + return (NULL); + } + host = addr; + service = sbuf; + } else { + host = addr; + service = NULL; + } + + /* resolve */ + memset(&hints, 0, sizeof(hints)); + hints.ai_family = af; + hints.ai_socktype = SOCK_STREAM; + hints.ai_flags = AI_ADDRCONFIG; + if ((err = getaddrinfo(host, service, &hints, &res)) != 0) { + netdb_seterr(err); + return (NULL); + } + return (res); +} + + + +/* * Bind a socket to a specific local address */ int fetch_bind(int sd, int af, const char *addr) { - struct addrinfo hints, *res, *res0; + struct addrinfo *cliai, *ai; int err; - memset(&hints, 0, sizeof(hints)); - hints.ai_family = af; - hints.ai_socktype = SOCK_STREAM; - hints.ai_protocol = 0; - if ((err = getaddrinfo(addr, NULL, &hints, &res0)) != 0) + if ((cliai = fetch_resolve(addr, 0, af)) == NULL) return (-1); - for (res = res0; res; res = res->ai_next) - if (bind(sd, res->ai_addr, res->ai_addrlen) == 0) { - freeaddrinfo(res0); - return (0); - } - freeaddrinfo(res0); - return (-1); + for (ai = cliai; ai != NULL; ai = ai->ai_next) + if ((err = bind(sd, ai->ai_addr, ai->ai_addrlen)) == 0) + break; + if (err != 0) + fetch_syserr(); + freeaddrinfo(cliai); + return (err == 0 ? 0 : -1); } @@ -271,59 +323,76 @@ fetch_bind(int sd, int af, const char *addr) conn_t * fetch_connect(const char *host, int port, int af, int verbose) { - conn_t *conn; - char pbuf[10]; + struct addrinfo *cais = NULL, *sais = NULL, *cai, *sai; const char *bindaddr; - struct addrinfo hints, *res, *res0; - int sd, err; + conn_t *conn = NULL; + int err = 0, sd = -1; DEBUG(fprintf(stderr, "---> %s:%d\n", host, port)); + /* resolve server address */ if (verbose) - fetch_info("looking up %s", host); + fetch_info("resolving server address: %s:%d", host, port); + if ((sais = fetch_resolve(host, port, af)) == NULL) + goto fail; - /* look up host name and set up socket address structure */ - snprintf(pbuf, sizeof(pbuf), "%d", port); - memset(&hints, 0, sizeof(hints)); - hints.ai_family = af; - hints.ai_socktype = SOCK_STREAM; - hints.ai_protocol = 0; - if ((err = getaddrinfo(host, pbuf, &hints, &res0)) != 0) { - netdb_seterr(err); - return (NULL); - } + /* resolve client address */ bindaddr = getenv("FETCH_BIND_ADDRESS"); + if (bindaddr != NULL && *bindaddr != '\0') { + if (verbose) + fetch_info("resolving client address: %s", bindaddr); + if ((cais = fetch_resolve(bindaddr, 0, af)) == NULL) + goto fail; + } - if (verbose) - fetch_info("connecting to %s:%d", host, port); - - /* try to connect */ - for (sd = -1, res = res0; res; sd = -1, res = res->ai_next) { - if ((sd = socket(res->ai_family, res->ai_socktype, - res->ai_protocol)) == -1) - continue; - if (bindaddr != NULL && *bindaddr != '\0' && - fetch_bind(sd, res->ai_family, bindaddr) != 0) { - fetch_info("failed to bind to '%s'", bindaddr); - close(sd); - continue; + /* try each server address in turn */ + for (err = 0, sai = sais; sai != NULL; sai = sai->ai_next) { + /* open socket */ + if ((sd = socket(sai->ai_family, SOCK_STREAM, 0)) < 0) + goto syserr; + /* attempt to bind to client address */ + for (err = 0, cai = cais; cai != NULL; cai = cai->ai_next) { + if (cai->ai_family != sai->ai_family) + continue; + if ((err = bind(sd, cai->ai_addr, cai->ai_addrlen)) == 0) + break; } - if (connect(sd, res->ai_addr, res->ai_addrlen) == 0 && - fcntl(sd, F_SETFL, O_NONBLOCK) == 0) + if (err != 0) { + if (verbose) + fetch_info("failed to bind to %s", bindaddr); + goto syserr; + } + /* attempt to connect to server address */ + if ((err = connect(sd, sai->ai_addr, sai->ai_addrlen)) == 0) break; + /* clean up before next attempt */ close(sd); + sd = -1; } - freeaddrinfo(res0); - if (sd == -1) { - fetch_syserr(); - return (NULL); + if (err != 0) { + if (verbose) + fetch_info("failed to connect to %s:%s", host, port); + goto syserr; } - if ((conn = fetch_reopen(sd)) == NULL) { - fetch_syserr(); - close(sd); - } + if ((conn = fetch_reopen(sd)) == NULL) + goto syserr; + if (cais != NULL) + freeaddrinfo(cais); + if (sais != NULL) + freeaddrinfo(sais); return (conn); +syserr: + fetch_syserr(); + goto fail; +fail: + if (sd >= 0) + close(sd); + if (cais != NULL) + freeaddrinfo(cais); + if (sais != NULL) + freeaddrinfo(sais); + return (NULL); } #ifdef WITH_SSL diff --git a/lib/libfetch/common.h b/lib/libfetch/common.h index 41c10d2..e881c88 100644 --- a/lib/libfetch/common.h +++ b/lib/libfetch/common.h @@ -76,6 +76,7 @@ void fetch_syserr(void); void fetch_info(const char *, ...); int fetch_default_port(const char *); int fetch_default_proxy_port(const char *); +struct addrinfo *fetch_resolve(const char *, int, int); int fetch_bind(int, int, const char *); conn_t *fetch_connect(const char *, int, int, int); conn_t *fetch_reopen(int); diff --git a/lib/libfetch/ftp.c b/lib/libfetch/ftp.c index dd58c0d..814c4a3 100644 --- a/lib/libfetch/ftp.c +++ b/lib/libfetch/ftp.c @@ -768,8 +768,8 @@ ftp_transfer(conn_t *conn, const char *oper, const char *file, fetch_info("opening data connection"); bindaddr = getenv("FETCH_BIND_ADDRESS"); if (bindaddr != NULL && *bindaddr != '\0' && - fetch_bind(sd, sa.ss_family, bindaddr) != 0) - goto sysouch; + (e = fetch_bind(sd, sa.ss_family, bindaddr)) != 0) + goto ouch; if (connect(sd, (struct sockaddr *)&sa, sa.ss_len) == -1) goto sysouch; -- cgit v1.1