From: David Gibson <david@gibson.dropbear.id.au>
To: passt-dev@passt.top, Stefano Brivio <sbrivio@redhat.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Subject: [PATCH 06/16] conf: Use array indices rather than pointers for DNS array slots
Date: Wed, 14 Aug 2024 14:30:40 +1000 [thread overview]
Message-ID: <20240814043050.4177037-7-david@gibson.dropbear.id.au> (raw)
In-Reply-To: <20240814043050.4177037-1-david@gibson.dropbear.id.au>
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 <david@gibson.dropbear.id.au>
---
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;
}
--
@@ -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
next prev parent reply other threads:[~2024-08-14 4:31 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-14 4:30 [PATCH 00/16] Cleanups and fixes related to "our" addresses David Gibson
2024-08-14 4:30 ` [PATCH 01/16] conf: Don't ignore -t and -u options after -D David Gibson
2024-08-14 12:18 ` Stefano Brivio
2024-08-14 4:30 ` [PATCH 02/16] treewide: Use "our address" instead of "forwarding address" David Gibson
2024-08-14 4:30 ` [PATCH 03/16] util: Helper for formatting MAC addresses David Gibson
2024-08-14 4:30 ` [PATCH 04/16] treewide: Rename MAC address fields for clarity David Gibson
2024-08-14 4:30 ` [PATCH 05/16] treewide: Use struct assignment instead of memcpy() for IP addresses David Gibson
2024-08-14 4:30 ` David Gibson [this message]
2024-08-14 4:30 ` [PATCH 07/16] conf: More accurately count entries added in get_dns() David Gibson
2024-08-14 4:30 ` [PATCH 08/16] conf: Move DNS array bounds checks into add_dns[46] David Gibson
2024-08-14 4:30 ` [PATCH 09/16] conf: Move adding of a nameserver from resolv.conf into subfunction David Gibson
2024-08-14 4:30 ` [PATCH 10/16] conf: Correct setting of dns_match address in add_dns6() David Gibson
2024-08-14 4:30 ` [PATCH 11/16] conf: Treat --dns addresses as guest visible addresses David Gibson
2024-08-14 4:30 ` [PATCH 12/16] conf: Remove incorrect initialisation of addr_ll_seen David Gibson
2024-08-14 4:30 ` [PATCH 13/16] util: Correct sock_l4() binding for link local addresses David Gibson
2024-08-14 4:30 ` [PATCH 14/16] treewide: Change misleading 'addr_ll' name David Gibson
2024-08-14 4:30 ` [PATCH 15/16] Clarify which addresses in ip[46]_ctx are meaningful where David Gibson
2024-08-14 4:30 ` [PATCH 16/16] Initialise our_tap_ll to ip6.gw when suitable David Gibson
2024-08-14 4:39 ` David Gibson
2024-08-14 5:03 ` [PATCH 00/16] Cleanups and fixes related to "our" addresses David Gibson
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