Merge pull request #19362 from yuwata/network-dhcp6-pd-log-19354

network: dhcp6: add logs about delegated prefix

3 files changed, 78 insertions, 11 deletions

diff --git a/src/network/networkd-dhcp6.c b/src/network/networkd-dhcp6.c
index 6f3c02d44d..a1211b86fb 100644
--- a/src/network/networkd-dhcp6.c
+++ b/src/network/networkd-dhcp6.c
@@ -364,6 +364,33 @@ static int dhcp6_pd_address_handler(sd_netlink *rtnl, sd_netlink_message *m, Lin
         return 1;
 }
 
+static void log_dhcp6_pd_address(Link *link, const Address *address) {
+        char valid_buf[FORMAT_TIMESPAN_MAX], preferred_buf[FORMAT_TIMESPAN_MAX];
+        const char *valid_str = NULL, *preferred_str = NULL;
+        _cleanup_free_ char *buffer = NULL;
+        int log_level;
+
+        log_level = address_get(link, address, NULL) >= 0 ? LOG_DEBUG : LOG_INFO;
+
+        if (log_level < log_get_max_level())
+                return;
+
+        (void) in_addr_prefix_to_string(address->family, &address->in_addr, address->prefixlen, &buffer);
+        if (address->cinfo.ifa_valid != CACHE_INFO_INFINITY_LIFE_TIME)
+                valid_str = format_timespan(valid_buf, FORMAT_TIMESPAN_MAX,
+                                            address->cinfo.ifa_valid * USEC_PER_SEC,
+                                            USEC_PER_SEC);
+        if (address->cinfo.ifa_prefered != CACHE_INFO_INFINITY_LIFE_TIME)
+                preferred_str = format_timespan(preferred_buf, FORMAT_TIMESPAN_MAX,
+                                                address->cinfo.ifa_prefered * USEC_PER_SEC,
+                                                USEC_PER_SEC);
+
+        log_link_full(link, log_level, "DHCPv6-PD address %s (valid %s%s, preferred %s%s)",
+                      strna(buffer),
+                      valid_str ? "for " : "forever", strempty(valid_str),
+                      preferred_str ? "for " : "forever", strempty(preferred_str));
+}
+
 static int dhcp6_set_pd_address(
                 Link *link,
                 const union in_addr_union *prefix,
@@ -402,6 +429,7 @@ static int dhcp6_set_pd_address(
         SET_FLAG(address->flags, IFA_F_MANAGETEMPADDR, link->network->dhcp6_pd_manage_temporary_address);
         address->route_metric = link->network->dhcp6_pd_route_metric;
 
+        log_dhcp6_pd_address(link, address);
         r = address_configure(address, link, dhcp6_pd_address_handler, &ret);
         if (r < 0)
                 return log_link_error_errno(link, r, "Failed to set DHCPv6 delegated prefix address: %m");
@@ -654,6 +682,8 @@ static void dhcp6_pd_prefix_lost(Link *dhcp6_link) {
                 if (r < 0)
                         link_enter_failed(link);
         }
+
+        set_clear(dhcp6_link->dhcp6_pd_prefixes);
 }
 
 static int dhcp6_remove_old(Link *link, bool force);
@@ -796,20 +826,12 @@ static int dhcp6_set_unreachable_route(Link *link, const union in_addr_union *ad
 
         (void) in_addr_prefix_to_string(AF_INET6, addr, prefixlen, &buf);
 
-        if (prefixlen > 64) {
-                log_link_debug(link, "PD Prefix length > 64, ignoring prefix %s", strna(buf));
-                return 0;
-        }
-
         if (prefixlen == 64) {
                 log_link_debug(link, "Not adding a blocking route for DHCPv6 delegated subnet %s since distributed prefix is 64",
                                strna(buf));
-                return 1;
+                return 0;
         }
 
-        if (prefixlen < 48)
-                log_link_warning(link, "PD Prefix length < 48, looks unusual: %s", strna(buf));
-
         r = route_new(&route);
         if (r < 0)
                 return log_oom();
@@ -837,7 +859,45 @@ static int dhcp6_set_unreachable_route(Link *link, const union in_addr_union *ad
 
         (void) set_remove(link->dhcp6_routes_old, ret);
 
-        return 1;
+        return 0;
+}
+
+static int dhcp6_pd_prefix_add(Link *link, const union in_addr_union *prefix, uint8_t prefixlen) {
+        _cleanup_free_ struct in_addr_prefix *p = NULL;
+        _cleanup_free_ char *buf = NULL;
+        int r;
+
+        assert(link);
+        assert(prefix);
+
+        p = new(struct in_addr_prefix, 1);
+        if (!p)
+                return log_oom();
+
+        *p = (struct in_addr_prefix) {
+                .family = AF_INET6,
+                .prefixlen = prefixlen,
+                .address = *prefix,
+        };
+
+        (void) in_addr_prefix_to_string(p->family, &p->address, p->prefixlen, &buf);
+
+        log_link_full(link,
+                      set_contains(link->dhcp6_pd_prefixes, p) ? LOG_DEBUG :
+                      prefixlen > 64 || prefixlen < 48 ? LOG_WARNING : LOG_INFO,
+                      "DHCP6: received PD Prefix %s%s",
+                      strna(buf),
+                      prefixlen > 64 ? " with prefix length > 64, ignoring." :
+                      prefixlen < 48 ? " with prefix lenght < 48, looks unusual.": "");
+
+        /* Store PD prefix even if prefixlen > 64, not to make logged at warning level so frequently. */
+        r = set_ensure_put(&link->dhcp6_pd_prefixes, &in_addr_prefix_hash_ops_free, p);
+        if (r < 0)
+                return log_link_error_errno(link, r, "Failed to store DHCP6 PD prefix %s: %m", strna(buf));
+        if (r > 0)
+                TAKE_PTR(p);
+
+        return prefixlen <= 64;
 }
 
 static int dhcp6_pd_prefix_acquired(Link *dhcp6_link) {
@@ -866,12 +926,16 @@ static int dhcp6_pd_prefix_acquired(Link *dhcp6_link) {
                 if (r < 0)
                         break;
 
-                r = dhcp6_set_unreachable_route(dhcp6_link, &pd_prefix, pd_prefix_len);
+                r = dhcp6_pd_prefix_add(dhcp6_link, &pd_prefix, pd_prefix_len);
                 if (r < 0)
                         return r;
                 if (r == 0)
                         continue;
 
+                r = dhcp6_set_unreachable_route(dhcp6_link, &pd_prefix, pd_prefix_len);
+                if (r < 0)
+                        return r;
+
                 /* We are doing prefix allocation in two steps:
                  * 1. all those links that have a preferred subnet id will be assigned their subnet
                  * 2. all those links that remain will receive prefixes in sequential order. Prefixes
diff --git a/src/network/networkd-link.c b/src/network/networkd-link.c
index 5143502745..127780ec60 100644
--- a/src/network/networkd-link.c
+++ b/src/network/networkd-link.c
@@ -573,6 +573,8 @@ static Link *link_free(Link *link) {
         link->dhcp6_pd_addresses_old = set_free(link->dhcp6_pd_addresses_old);
         link->ndisc_addresses = set_free(link->ndisc_addresses);
 
+        link->dhcp6_pd_prefixes = set_free(link->dhcp6_pd_prefixes);
+
         link_free_engines(link);
 
         free(link->ifname);
diff --git a/src/network/networkd-link.h b/src/network/networkd-link.h
index a8bdd971f5..a9f6cf61eb 100644
--- a/src/network/networkd-link.h
+++ b/src/network/networkd-link.h
@@ -151,6 +151,7 @@ typedef struct Link {
         sd_dhcp6_lease *dhcp6_lease;
         Set *dhcp6_addresses, *dhcp6_addresses_old;
         Set *dhcp6_routes, *dhcp6_routes_old;
+        Set *dhcp6_pd_prefixes;
         Set *dhcp6_pd_addresses, *dhcp6_pd_addresses_old;
         Set *dhcp6_pd_routes, *dhcp6_pd_routes_old;
         unsigned dhcp6_address_messages;