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Diffstat (limited to 'accel-pppd/ipv6/nd.c')
-rw-r--r--accel-pppd/ipv6/nd.c88
1 files changed, 63 insertions, 25 deletions
diff --git a/accel-pppd/ipv6/nd.c b/accel-pppd/ipv6/nd.c
index 8b22da14..674dff53 100644
--- a/accel-pppd/ipv6/nd.c
+++ b/accel-pppd/ipv6/nd.c
@@ -22,13 +22,10 @@
#include "memdebug.h"
-#define MAX_DNS_COUNT 3
-
static int conf_init_ra = 5;
static int conf_init_ra_interval = 3;
static int conf_rdnss_lifetime;
-static struct in6_addr conf_dns[MAX_DNS_COUNT];
-static int conf_dns_count;
+static struct ipv6_dns_t conf_dns;
static uint8_t *conf_dnssl;
static int conf_dnssl_size;
@@ -107,9 +104,12 @@ static void ipv6_nd_send_ra(struct ipv6_nd_handler_t *h, struct sockaddr_in6 *ds
struct nd_opt_dnssl_info_local *dnsslinfo;
//struct nd_opt_mtu *mtu;
struct ipv6db_addr_t *a;
+ const struct in6_addr *dns;
struct in6_addr addr, peer_addr;
- struct in6_addr dns[MAX_DNS_COUNT];
+ char str[INET6_ADDRSTRLEN];
+ void *bufend;
int i, prefix_len, dns_count;
+ size_t avail, dnssl_size, max_dns;
if (!buf) {
log_emerg("out of memory\n");
@@ -132,20 +132,31 @@ static void ipv6_nd_send_ra(struct ipv6_nd_handler_t *h, struct sockaddr_in6 *ds
adv->nd_ra_retransmit = htonl(conf_AdvRetransTimer);
pinfo = (struct nd_opt_prefix_info *)(adv + 1);
+ bufend = (uint8_t *)buf + BUF_SIZE;
list_for_each_entry(a, &ses->ipv6->addr_list, entry) {
prefix_len = a->prefix_len == 128 ? 64 : a->prefix_len;
- memset(pinfo, 0, sizeof(*pinfo));
- pinfo->nd_opt_pi_type = ND_OPT_PREFIX_INFORMATION;
- pinfo->nd_opt_pi_len = 4;
- pinfo->nd_opt_pi_prefix_len = prefix_len;
- pinfo->nd_opt_pi_flags_reserved =
- ((a->flag_onlink || conf_AdvPrefixOnLinkFlag) ? ND_OPT_PI_FLAG_ONLINK : 0) |
- ((a->flag_auto || (conf_AdvPrefixAutonomousFlag && prefix_len == 64)) ? ND_OPT_PI_FLAG_AUTO : 0);
- pinfo->nd_opt_pi_valid_time = htonl(conf_AdvPrefixValidLifetime);
- pinfo->nd_opt_pi_preferred_time = htonl(conf_AdvPrefixPreferredLifetime);
- memcpy(&pinfo->nd_opt_pi_prefix, &a->addr, (prefix_len + 7) / 8);
- pinfo->nd_opt_pi_prefix.s6_addr[prefix_len / 8] &= ~(0xff >> (prefix_len % 8));
- pinfo++;
+
+ /* Addresses are installed even when the advertisement is
+ already full, only their prefix information is dropped */
+ if ((void *)(pinfo + 1) > bufend) {
+ log_ppp_warn("ipv6_nd: prefix %s/%i does not fit into the"
+ " router advertisement, not advertising it\n",
+ inet_ntop(AF_INET6, &a->addr, str, sizeof(str)),
+ prefix_len);
+ } else {
+ memset(pinfo, 0, sizeof(*pinfo));
+ pinfo->nd_opt_pi_type = ND_OPT_PREFIX_INFORMATION;
+ pinfo->nd_opt_pi_len = 4;
+ pinfo->nd_opt_pi_prefix_len = prefix_len;
+ pinfo->nd_opt_pi_flags_reserved =
+ ((a->flag_onlink || conf_AdvPrefixOnLinkFlag) ? ND_OPT_PI_FLAG_ONLINK : 0) |
+ ((a->flag_auto || (conf_AdvPrefixAutonomousFlag && prefix_len == 64)) ? ND_OPT_PI_FLAG_AUTO : 0);
+ pinfo->nd_opt_pi_valid_time = htonl(conf_AdvPrefixValidLifetime);
+ pinfo->nd_opt_pi_preferred_time = htonl(conf_AdvPrefixPreferredLifetime);
+ memcpy(&pinfo->nd_opt_pi_prefix, &a->addr, (prefix_len + 7) / 8);
+ pinfo->nd_opt_pi_prefix.s6_addr[prefix_len / 8] &= ~(0xff >> (prefix_len % 8));
+ pinfo++;
+ }
if (!a->installed) {
if (a->prefix_len == 128) {
@@ -176,7 +187,31 @@ static void ipv6_nd_send_ra(struct ipv6_nd_handler_t *h, struct sockaddr_in6 *ds
rinfo++;
}*/
- dns_count = ipv6_dns_get(ses, conf_dns, conf_dns_count, dns, MAX_DNS_COUNT);
+ dns = ipv6_dns_get(ses, conf_dns.addr, conf_dns.count, &dns_count);
+
+ /* Room left behind the prefix information options, shared by the RDNSS
+ and DNSSL options which follow. The search list is sized by the
+ configuration alone, so give it its share first */
+ avail = (uint8_t *)bufend - (uint8_t *)pinfo;
+ dnssl_size = conf_dnssl ? (1 + (conf_dnssl_size - 1) / 8 + 1) * 8 : 0;
+ if (dnssl_size > avail) {
+ log_ppp_warn("ipv6_nd: DNS search list does not fit into the router"
+ " advertisement, not advertising it\n");
+ dnssl_size = 0;
+ }
+ avail -= dnssl_size;
+
+ /* nd_opt_rdnssi_len counts 8 byte units in a single octet, so an
+ advertisement carries at most 127 addresses however large it is */
+ max_dns = avail > sizeof(*rdnssinfo) ? (avail - sizeof(*rdnssinfo)) / sizeof(*dns) : 0;
+ if (max_dns > 127)
+ max_dns = 127;
+ if ((size_t)dns_count > max_dns) {
+ log_ppp_warn("ipv6_nd: advertising %zu of %i DNS servers, the rest"
+ " does not fit into the router advertisement\n",
+ max_dns, dns_count);
+ dns_count = (int)max_dns;
+ }
if (dns_count) {
rdnssinfo = (struct nd_opt_rdnss_info_local *)pinfo;
@@ -186,13 +221,13 @@ static void ipv6_nd_send_ra(struct ipv6_nd_handler_t *h, struct sockaddr_in6 *ds
rdnssinfo->nd_opt_rdnssi_lifetime = htonl(conf_rdnss_lifetime);
rdnss_addr = (struct in6_addr *)rdnssinfo->nd_opt_rdnssi;
for (i = 0; i < dns_count; i++) {
- memcpy(rdnss_addr, &dns[i], sizeof(*rdnss_addr));
+ memcpy(rdnss_addr, dns + i, sizeof(*rdnss_addr));
rdnss_addr++;
}
} else
rdnss_addr = (struct in6_addr *)pinfo;
- if (conf_dnssl) {
+ if (dnssl_size) {
dnsslinfo = (struct nd_opt_dnssl_info_local *)rdnss_addr;
memset(dnsslinfo, 0, sizeof(*dnsslinfo));
dnsslinfo->nd_opt_dnssli_type = ND_OPT_DNSSL_INFORMATION;
@@ -471,7 +506,7 @@ static void load_dns(void)
if (!s)
return;
- conf_dns_count = 0;
+ conf_dns.count = 0;
if (conf_dnssl)
_free(conf_dnssl);
@@ -491,14 +526,17 @@ static void load_dns(void)
}
if (!strcmp(opt->name, "dns") || !opt->val) {
- if (conf_dns_count == MAX_DNS_COUNT)
- continue;
+ if (ipv6_dns_reserve(&conf_dns, conf_dns.count + 1)) {
+ log_emerg("ipv6_nd: out of memory allocating IPv6 DNS servers\n");
+ break;
+ }
- if (inet_pton(AF_INET6, opt->val ? opt->val : opt->name, &conf_dns[conf_dns_count]) == 0) {
+ if (inet_pton(AF_INET6, opt->val ? opt->val : opt->name,
+ &conf_dns.addr[conf_dns.count]) == 0) {
log_error("dnsv6: failed to parse '%s'\n", opt->name);
continue;
}
- conf_dns_count++;
+ conf_dns.count++;
}
}
}
generated by cgit v1.2.3 (git 2.39.1) at 2026-10-07 05:53:24 +0000