[PATCH] iscsi_ibft: Print correct IPv6 netmask

Hannes Reinecke
2014-07-16T14:31:29Z

The iBFT table only specifies a prefix length, so we need to
check the given IP address to figure out whether the netmask
should be printed in IPv4 or IPv6 style.

Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Peter Jones <pjones@redhat.com>
Cc: Konrad Rzeszutek Wilk <konrad@kernel.org>
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
drivers/firmware/iscsi_ibft.c | 35 ++++++++++++++++++++++++++++++++---
1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/drivers/firmware/iscsi_ibft.c b/drivers/firmware/iscsi_ibft.c
index 071c2c9..7fddab9 100644
--- a/drivers/firmware/iscsi_ibft.c
+++ b/drivers/firmware/iscsi_ibft.c
@@ -212,6 +212,36 @@ static ssize_t sprintf_ipaddr(char *buf, u8 *ip)
return str - buf;
}

+static ssize_t sprintf_netmask(char *buf, u8 *ip, unsigned int prefix_len)
+{
+ char *str = buf;
+
+ if (ip[0] == 0 && ip[1] == 0 && ip[2] == 0 && ip[3] == 0 &&
+ ip[4] == 0 && ip[5] == 0 && ip[6] == 0 && ip[7] == 0 &&
+ ip[8] == 0 && ip[9] == 0 && ip[10] == 0xff && ip[11] == 0xff) {
+ __be32 val;
+ /*
+ * IPV4
+ */
+ val = cpu_to_be32(~((1 << (32-prefix_len))-1));
+ str += sprintf(str, "%pI4", &val);
+ } else {
+ u8 netmask[16];
+ int o = prefix_len >> 3,
+ b = prefix_len & 0x7;
+ /*
+ * IPv6
+ */
+ memset(netmask, 0, 16);
+ memset(netmask, 0xff, o);
+ if (b != 0)
+ netmask[o] = 0xff & (0xff00 >> b);
+ str += sprintf(buf, "%pI6", netmask);
+ }
+ str += sprintf(str, "\n");
+ return str - buf;
+}
+
static ssize_t sprintf_string(char *str, int len, char *buf)
{
return sprintf(str, "%.*s\n", len, buf);
@@ -288,7 +318,6 @@ static ssize_t ibft_attr_show_nic(void *data, int type, char *buf)
struct ibft_nic *nic = entry->nic;
void *ibft_loc = entry->header;
char *str = buf;
- __be32 val;

if (!nic)
return 0;
@@ -304,8 +333,8 @@ static ssize_t ibft_attr_show_nic(void *data, int type, char *buf)
str += sprintf_ipaddr(str, nic->ip_addr);
break;
case ISCSI_BOOT_ETH_SUBNET_MASK:
- val = cpu_to_be32(~((1 << (32-nic->subnet_mask_prefix))-1));
- str += sprintf(str, "%pI4", &val);
+ str += sprintf_netmask(str, nic->ip_addr,
+ nic->subnet_mask_prefix);
break;
case ISCSI_BOOT_ETH_ORIGIN:
str += sprintf(str, "%d\n", nic->origin);
--
1.7.12.4