From: Stefano Brivio <sbrivio@redhat.com>
To: passt-dev@passt.top
Cc: Andrea Bolognani <abologna@redhat.com>
Subject: [PATCH 2/3] conf: Split add_dns{4,6}() out of get_dns()
Date: Thu, 23 Feb 2023 18:07:59 +0100 [thread overview]
Message-ID: <20230223170800.3888094-3-sbrivio@redhat.com> (raw)
In-Reply-To: <20230223170800.3888094-1-sbrivio@redhat.com>
The logic handling which resolvers we add, and whether to add them,
is getting rather cramped in get_dns(): split it into separate
functions.
No functional changes intended.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
---
conf.c | 86 ++++++++++++++++++++++++++++++++++------------------------
1 file changed, 51 insertions(+), 35 deletions(-)
diff --git a/conf.c b/conf.c
index 4dc0660..ed25e35 100644
--- a/conf.c
+++ b/conf.c
@@ -382,6 +382,53 @@ bind_fail:
die("Failed to bind any port for '-%c %s', exiting", optname, optarg);
}
+/**
+ * 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
+ */
+static void add_dns4(struct ctx *c, struct in_addr *addr, struct in_addr **conf)
+{
+ /* 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)++;
+ }
+ } else {
+ **conf = *addr;
+ (*conf)++;
+ }
+
+ if (IN4_IS_ADDR_UNSPECIFIED(&c->ip4.dns_host))
+ c->ip4.dns_host = *addr;
+}
+
+/**
+ * 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
+ */
+static void add_dns6(struct ctx *c,
+ struct in6_addr *addr, struct in6_addr **conf)
+{
+ /* Guest or container can only access local addresses via redirect */
+ if (IN6_IS_ADDR_LOOPBACK(addr)) {
+ if (!c->no_map_gw) {
+ memcpy(*conf, &c->ip6.gw, sizeof(**conf));
+ (*conf)++;
+ }
+ } else {
+ memcpy(*conf, addr, sizeof(**conf));
+ (*conf)++;
+ }
+
+ if (IN6_IS_ADDR_UNSPECIFIED(&c->ip6.dns_host))
+ c->ip6.dns_host = *addr;
+}
+
/**
* get_dns() - Get nameserver addresses from local /etc/resolv.conf
* @c: Execution context
@@ -420,44 +467,13 @@ static void get_dns(struct ctx *c)
if (!dns4_set &&
dns4 - &c->ip4.dns[0] < ARRAY_SIZE(c->ip4.dns) - 1
- && inet_pton(AF_INET, p + 1, &dns4_tmp)) {
- /* Guest or container can only access local
- * addresses via local redirect
- */
- if (IN4_IS_ADDR_LOOPBACK(&dns4_tmp)) {
- if (!c->no_map_gw) {
- *dns4 = c->ip4.gw;
- dns4++;
- }
- } else {
- *dns4 = dns4_tmp;
- dns4++;
- }
-
- if (IN4_IS_ADDR_UNSPECIFIED(&c->ip4.dns_host))
- c->ip4.dns_host = dns4_tmp;
- }
+ && inet_pton(AF_INET, p + 1, &dns4_tmp))
+ add_dns4(c, &dns4_tmp, &dns4);
if (!dns6_set &&
dns6 - &c->ip6.dns[0] < ARRAY_SIZE(c->ip6.dns) - 1
- && inet_pton(AF_INET6, p + 1, &dns6_tmp)) {
- /* Guest or container can only access local
- * addresses via local redirect
- */
- if (IN6_IS_ADDR_LOOPBACK(&dns6_tmp)) {
- if (!c->no_map_gw) {
- memcpy(dns6, &c->ip6.gw,
- sizeof(*dns6));
- dns6++;
- }
- } else {
- memcpy(dns6, &dns6_tmp, sizeof(*dns6));
- dns6++;
- }
-
- if (IN6_IS_ADDR_UNSPECIFIED(&c->ip6.dns_host))
- c->ip6.dns_host = dns6_tmp;
- }
+ && inet_pton(AF_INET6, p + 1, &dns6_tmp))
+ add_dns6(c, &dns6_tmp, &dns6);
} else if (!dnss_set && strstr(line, "search ") == line &&
s == c->dns_search) {
end = strpbrk(line, "\n");
--
@@ -382,6 +382,53 @@ bind_fail:
die("Failed to bind any port for '-%c %s', exiting", optname, optarg);
}
+/**
+ * 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
+ */
+static void add_dns4(struct ctx *c, struct in_addr *addr, struct in_addr **conf)
+{
+ /* 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)++;
+ }
+ } else {
+ **conf = *addr;
+ (*conf)++;
+ }
+
+ if (IN4_IS_ADDR_UNSPECIFIED(&c->ip4.dns_host))
+ c->ip4.dns_host = *addr;
+}
+
+/**
+ * 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
+ */
+static void add_dns6(struct ctx *c,
+ struct in6_addr *addr, struct in6_addr **conf)
+{
+ /* Guest or container can only access local addresses via redirect */
+ if (IN6_IS_ADDR_LOOPBACK(addr)) {
+ if (!c->no_map_gw) {
+ memcpy(*conf, &c->ip6.gw, sizeof(**conf));
+ (*conf)++;
+ }
+ } else {
+ memcpy(*conf, addr, sizeof(**conf));
+ (*conf)++;
+ }
+
+ if (IN6_IS_ADDR_UNSPECIFIED(&c->ip6.dns_host))
+ c->ip6.dns_host = *addr;
+}
+
/**
* get_dns() - Get nameserver addresses from local /etc/resolv.conf
* @c: Execution context
@@ -420,44 +467,13 @@ static void get_dns(struct ctx *c)
if (!dns4_set &&
dns4 - &c->ip4.dns[0] < ARRAY_SIZE(c->ip4.dns) - 1
- && inet_pton(AF_INET, p + 1, &dns4_tmp)) {
- /* Guest or container can only access local
- * addresses via local redirect
- */
- if (IN4_IS_ADDR_LOOPBACK(&dns4_tmp)) {
- if (!c->no_map_gw) {
- *dns4 = c->ip4.gw;
- dns4++;
- }
- } else {
- *dns4 = dns4_tmp;
- dns4++;
- }
-
- if (IN4_IS_ADDR_UNSPECIFIED(&c->ip4.dns_host))
- c->ip4.dns_host = dns4_tmp;
- }
+ && inet_pton(AF_INET, p + 1, &dns4_tmp))
+ add_dns4(c, &dns4_tmp, &dns4);
if (!dns6_set &&
dns6 - &c->ip6.dns[0] < ARRAY_SIZE(c->ip6.dns) - 1
- && inet_pton(AF_INET6, p + 1, &dns6_tmp)) {
- /* Guest or container can only access local
- * addresses via local redirect
- */
- if (IN6_IS_ADDR_LOOPBACK(&dns6_tmp)) {
- if (!c->no_map_gw) {
- memcpy(dns6, &c->ip6.gw,
- sizeof(*dns6));
- dns6++;
- }
- } else {
- memcpy(dns6, &dns6_tmp, sizeof(*dns6));
- dns6++;
- }
-
- if (IN6_IS_ADDR_UNSPECIFIED(&c->ip6.dns_host))
- c->ip6.dns_host = dns6_tmp;
- }
+ && inet_pton(AF_INET6, p + 1, &dns6_tmp))
+ add_dns6(c, &dns6_tmp, &dns6);
} else if (!dnss_set && strstr(line, "search ") == line &&
s == c->dns_search) {
end = strpbrk(line, "\n");
--
2.39.1
next prev parent reply other threads:[~2023-02-23 17:08 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-23 17:07 [PATCH 0/3] Allow non-127.0.0.1 loopback address as host resolver Stefano Brivio
2023-02-23 17:07 ` [PATCH 1/3] udp: Actually use host resolver to forward DNS queries Stefano Brivio
2023-02-27 12:02 ` David Gibson
2023-02-23 17:07 ` Stefano Brivio [this message]
2023-02-27 12:04 ` [PATCH 2/3] conf: Split add_dns{4,6}() out of get_dns() David Gibson
2023-02-23 17:08 ` [PATCH 3/3] conf, udp: Allow any loopback address to be used as resolver Stefano Brivio
2023-02-27 12:07 ` David Gibson
2023-02-23 17:53 ` [PATCH 0/3] Allow non-127.0.0.1 loopback address as host resolver Andrea Bolognani
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