From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) by passt.top (Postfix) with ESMTPS id 86C305A0332 for ; Wed, 14 Aug 2024 06:31:04 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gibson.dropbear.id.au; s=202312; t=1723609853; bh=IwC/ELMj3PqLFg6jeX76FozJ8vVyYO29m69cfIgUDdk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nQSrt5dlZv0t9Toeoh0S8iF/wPKJ778IVXslKKQkeE44BBuuQ4OoEZaAGl5Hn5PD6 k6mR4lC3gXw1si8fZP7Hc1HAh/ZUCz3HI8s/CrD3ZyfsMba5Lzwy60Zw21+0nAOj30 gaKlhg/NhFddRSfveHHmZZ8geYCYYNjj3AAwVEksN2UFxae8LhCLvzYELnr5o5GrWC oeWL/dvBpo+5/scrZZ6MXg8rT4NevZVCNX53T6URHdnHabCL/OX8aGU62JjtTwILRN UiYpMxhUb1j6We1emjAXxE0jBPRGuPLwGqnUdA7xg9xUJScCtCCwouwKKeJG+l3ej8 2bimcH2/rssSA== Received: by gandalf.ozlabs.org (Postfix, from userid 1007) id 4WkFgK1txnz4xCg; Wed, 14 Aug 2024 14:30:53 +1000 (AEST) From: David Gibson To: passt-dev@passt.top, Stefano Brivio Subject: [PATCH 06/16] conf: Use array indices rather than pointers for DNS array slots Date: Wed, 14 Aug 2024 14:30:40 +1000 Message-ID: <20240814043050.4177037-7-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240814043050.4177037-1-david@gibson.dropbear.id.au> References: <20240814043050.4177037-1-david@gibson.dropbear.id.au> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Message-ID-Hash: EOPUAC2KX7TBSSEOBURW4HULY6AOTI74 X-Message-ID-Hash: EOPUAC2KX7TBSSEOBURW4HULY6AOTI74 X-MailFrom: dgibson@gandalf.ozlabs.org X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: David Gibson X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Currently add_dns[46]() take a somewhat awkward double pointer to the entry in the c->ip[46].dns array to update. It turns out to be easier to work with indices into that array instead. This diff does add some lines, but it's comments, and will allow some future code reductions. Signed-off-by: David Gibson --- conf.c | 73 +++++++++++++++++++++++++++++++++------------------------- 1 file changed, 41 insertions(+), 32 deletions(-) diff --git a/conf.c b/conf.c index 9b05afeb..286b3e9f 100644 --- a/conf.c +++ b/conf.c @@ -354,54 +354,65 @@ bind_all_fail: * add_dns4() - Possibly add the IPv4 address of a DNS resolver to configuration * @c: Execution context * @addr: Address found in /etc/resolv.conf - * @conf: Pointer to reference of current entry in array of IPv4 resolvers + * @idx: Index of free entry in array of IPv4 resolvers + * + * Return: Number of entries added (0 or 1) */ -static void add_dns4(struct ctx *c, const struct in_addr *addr, - struct in_addr **conf) +static unsigned add_dns4(struct ctx *c, const struct in_addr *addr, + unsigned idx) { + unsigned added = 0; + /* Guest or container can only access local addresses via redirect */ if (IN4_IS_ADDR_LOOPBACK(addr)) { if (!c->no_map_gw) { - **conf = c->ip4.gw; - (*conf)++; + c->ip4.dns[idx] = c->ip4.gw; + added++; if (IN4_IS_ADDR_UNSPECIFIED(&c->ip4.dns_match)) c->ip4.dns_match = c->ip4.gw; } } else { - **conf = *addr; - (*conf)++; + c->ip4.dns[idx] = *addr; + added++; } if (IN4_IS_ADDR_UNSPECIFIED(&c->ip4.dns_host)) c->ip4.dns_host = *addr; + + return added; } /** * add_dns6() - Possibly add the IPv6 address of a DNS resolver to configuration * @c: Execution context * @addr: Address found in /etc/resolv.conf - * @conf: Pointer to reference of current entry in array of IPv6 resolvers + * @idx: Index of free entry in array of IPv4 resolvers + * + * Return: Number of entries added (0 or 1) */ -static void add_dns6(struct ctx *c, - struct in6_addr *addr, struct in6_addr **conf) +static unsigned add_dns6(struct ctx *c, struct in6_addr *addr, unsigned idx) { + unsigned added = 0; + /* Guest or container can only access local addresses via redirect */ if (IN6_IS_ADDR_LOOPBACK(addr)) { if (!c->no_map_gw) { - **conf = c->ip6.gw; - (*conf)++; + c->ip6.dns[idx] = c->ip6.gw; + added++; if (IN6_IS_ADDR_UNSPECIFIED(&c->ip6.dns_match)) c->ip6.dns_match = *addr; } } else { - **conf = *addr; - (*conf)++; + c->ip6.dns[idx] = *addr; + added++; } if (IN6_IS_ADDR_UNSPECIFIED(&c->ip6.dns_host)) c->ip6.dns_host = *addr; + + return added; } /** @@ -410,18 +421,19 @@ static void add_dns6(struct ctx *c, */ static void get_dns(struct ctx *c) { - struct in6_addr *dns6 = &c->ip6.dns[0], dns6_tmp; - struct in_addr *dns4 = &c->ip4.dns[0], dns4_tmp; int dns4_set, dns6_set, dnss_set, dns_set, fd; + unsigned dns4_idx = 0, dns6_idx = 0; struct fqdn *s = c->dns_search; struct lineread resolvconf; + struct in6_addr dns6_tmp; + struct in_addr dns4_tmp; unsigned int added = 0; ssize_t line_len; char *line, *end; const char *p; - dns4_set = !c->ifi4 || !IN4_IS_ADDR_UNSPECIFIED(dns4); - dns6_set = !c->ifi6 || !IN6_IS_ADDR_UNSPECIFIED(dns6); + dns4_set = !c->ifi4 || !IN4_IS_ADDR_UNSPECIFIED(&c->ip4.dns[0]); + dns6_set = !c->ifi6 || !IN6_IS_ADDR_UNSPECIFIED(&c->ip6.dns[0]); dnss_set = !!*s->n || c->no_dns_search; dns_set = (dns4_set && dns6_set) || c->no_dns; @@ -442,17 +454,15 @@ static void get_dns(struct ctx *c) if (end) *end = 0; - if (!dns4_set && - dns4 - &c->ip4.dns[0] < ARRAY_SIZE(c->ip4.dns) - 1 + if (!dns4_set && dns4_idx < ARRAY_SIZE(c->ip4.dns) - 1 && inet_pton(AF_INET, p + 1, &dns4_tmp)) { - add_dns4(c, &dns4_tmp, &dns4); + dns4_idx += add_dns4(c, &dns4_tmp, dns4_idx); added++; } - if (!dns6_set && - dns6 - &c->ip6.dns[0] < ARRAY_SIZE(c->ip6.dns) - 1 + if (!dns6_set && dns6_idx < ARRAY_SIZE(c->ip6.dns) - 1 && inet_pton(AF_INET6, p + 1, &dns6_tmp)) { - add_dns6(c, &dns6_tmp, &dns6); + dns6_idx += add_dns6(c, &dns6_tmp, dns6_idx); added++; } } else if (!dnss_set && strstr(line, "search ") == line && @@ -1236,8 +1246,7 @@ void conf(struct ctx *c, int argc, char **argv) bool copy_addrs_opt = false, copy_routes_opt = false; enum fwd_ports_mode fwd_default = FWD_NONE; bool v4_only = false, v6_only = false; - struct in6_addr *dns6 = c->ip6.dns; - struct in_addr *dns4 = c->ip4.dns; + unsigned dns4_idx = 0, dns6_idx = 0; struct fqdn *dnss = c->dns_search; unsigned int ifi4 = 0, ifi6 = 0; const char *logfile = NULL; @@ -1662,13 +1671,13 @@ void conf(struct ctx *c, int argc, char **argv) if (!strcmp(optarg, "none")) { c->no_dns = 1; - dns4 = &c->ip4.dns[0]; + dns4_idx = 0; memset(c->ip4.dns, 0, sizeof(c->ip4.dns)); c->ip4.dns[0] = (struct in_addr){ 0 }; c->ip4.dns_match = (struct in_addr){ 0 }; c->ip4.dns_host = (struct in_addr){ 0 }; - dns6 = &c->ip6.dns[0]; + dns6_idx = 0; memset(c->ip6.dns, 0, sizeof(c->ip6.dns)); c->ip6.dns_match = (struct in6_addr){ 0 }; c->ip6.dns_host = (struct in6_addr){ 0 }; @@ -1678,15 +1687,15 @@ void conf(struct ctx *c, int argc, char **argv) c->no_dns = 0; - if (dns4 - &c->ip4.dns[0] < ARRAY_SIZE(c->ip4.dns) && + if (dns4_idx < ARRAY_SIZE(c->ip4.dns) && inet_pton(AF_INET, optarg, &dns4_tmp)) { - add_dns4(c, &dns4_tmp, &dns4); + dns4_idx += add_dns4(c, &dns4_tmp, dns4_idx); continue; } - if (dns6 - &c->ip6.dns[0] < ARRAY_SIZE(c->ip6.dns) && + if (dns6_idx < ARRAY_SIZE(c->ip6.dns) && inet_pton(AF_INET6, optarg, &dns6_tmp)) { - add_dns6(c, &dns6_tmp, &dns6); + dns6_idx += add_dns6(c, &dns6_tmp, dns6_idx); continue; } -- 2.46.0