Scope ID support is needed since the kernel's NSM implementation is
about to use these displayed addresses as a mon_name in some cases.
When nsm_use_hostnames is zero, without scope ID support NSM will fail
to handle peers that contact us via a link-local address. Link-local
addresses do not work without an interface ID, which is stored in the
sockaddr's sin6_scope_id field.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
fs/lockd/host.c | 21 +++++++++++++++------
include/linux/lockd/lockd.h | 10 +++++++++-
2 files changed, 24 insertions(+), 7 deletions(-)
diff --git a/fs/lockd/host.c b/fs/lockd/host.c
index beb5da8..012e49a 100644
--- a/fs/lockd/host.c
+++ b/fs/lockd/host.c
@@ -105,22 +105,31 @@ static void nlm_clear_port(struct sockaddr *sap)
}
}
+static void nlm_display_ipv6_address(const struct sockaddr *sap, char *buf,
+ const size_t len)
+{
+ const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
+
+ if (ipv6_addr_v4mapped(&sin6->sin6_addr))
+ snprintf(buf, len, "%pI4", &sin6->sin6_addr.s6_addr32[3]);
+ else if (sin6->sin6_scope_id != 0)
+ snprintf(buf, len, "%pI6%%%u", &sin6->sin6_addr,
+ sin6->sin6_scope_id);
+ else
+ snprintf(buf, len, "%pI6", &sin6->sin6_addr);
+}
+
static void nlm_display_address(const struct sockaddr *sap,
char *buf, const size_t len)
{
const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
- const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
switch (sap->sa_family) {
case AF_INET:
snprintf(buf, len, "%pI4", &sin->sin_addr.s_addr);
break;
case AF_INET6:
- if (ipv6_addr_v4mapped(&sin6->sin6_addr))
- snprintf(buf, len, "%pI4",
- &sin6->sin6_addr.s6_addr32[3]);
- else
- snprintf(buf, len, "%pI6", &sin6->sin6_addr);
+ nlm_display_ipv6_address(sap, buf, len);
break;
default:
snprintf(buf, len, "unsupported address family");
diff --git a/include/linux/lockd/lockd.h b/include/linux/lockd/lockd.h
index dae22cb..80a0a2c 100644
--- a/include/linux/lockd/lockd.h
+++ b/include/linux/lockd/lockd.h
@@ -68,6 +68,14 @@ struct nlm_host {
char *h_addrbuf; /* address eyecatcher */
};
+/*
+ * The largest string sm_addrbuf should hold is a full-size IPv6 address
+ * (no "::" anywhere) with a scope ID. The buffer size is computed to
+ * hold eight groups of colon-separated four-hex-digit numbers, a
+ * percent sign, a scope id (at most 32 bits, in decimal), and NUL.
+ */
+#define NSM_ADDRBUF ((8 * 4 + 7) + (1 + 10) + 1)
+
struct nsm_handle {
struct list_head sm_link;
atomic_t sm_count;
@@ -76,7 +84,7 @@ struct nsm_handle {
size_t sm_addrlen;
unsigned int sm_monitored : 1,
sm_sticky : 1; /* don't unmonitor */
- char sm_addrbuf[48]; /* address eyecatcher */
+ char sm_addrbuf[NSM_ADDRBUF];
};
/*
--
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