summary refs log tree commit diff stats
path: root/hw/net
diff options
context:
space:
mode:
authorFinn Thain <fthain@telegraphics.com.au>2020-01-29 20:27:49 +1100
committerJason Wang <jasowang@redhat.com>2020-03-03 18:04:47 +0800
commitada74315270d1dcabf4c9d4fece19df7ef5b9577 (patch)
tree6228520087f920e3ea4bdd98fb30a73996aa3f5a /hw/net
parenta3cce2825a0b12bb717a5106daaca245557cc9ae (diff)
downloadfocaccia-qemu-ada74315270d1dcabf4c9d4fece19df7ef5b9577.tar.gz
focaccia-qemu-ada74315270d1dcabf4c9d4fece19df7ef5b9577.zip
dp8393x: Implement packet size limit and RBAE interrupt
Add a bounds check to prevent a large packet from causing a buffer
overflow. This is defensive programming -- I haven't actually tried
sending an oversized packet or a jumbo ethernet frame.

The SONIC handles packets that are too big for the buffer by raising
the RBAE interrupt and dropping them. Linux uses that interrupt to
count dropped packets.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Diffstat (limited to 'hw/net')
-rw-r--r--hw/net/dp8393x.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/hw/net/dp8393x.c b/hw/net/dp8393x.c
index b5a9c6ac0f..911f59e0c9 100644
--- a/hw/net/dp8393x.c
+++ b/hw/net/dp8393x.c
@@ -137,6 +137,7 @@ do { printf("sonic ERROR: %s: " fmt, __func__ , ## __VA_ARGS__); } while (0)
 #define SONIC_TCR_CRCI   0x2000
 #define SONIC_TCR_PINT   0x8000
 
+#define SONIC_ISR_RBAE   0x0010
 #define SONIC_ISR_RBE    0x0020
 #define SONIC_ISR_RDE    0x0040
 #define SONIC_ISR_TC     0x0080
@@ -772,6 +773,14 @@ static ssize_t dp8393x_receive(NetClientState *nc, const uint8_t * buf,
     s->regs[SONIC_RCR] &= ~(SONIC_RCR_PRX | SONIC_RCR_LBK | SONIC_RCR_FAER |
         SONIC_RCR_CRCR | SONIC_RCR_LPKT | SONIC_RCR_BC | SONIC_RCR_MC);
 
+    if (pkt_size + 4 > dp8393x_rbwc(s) * 2) {
+        DPRINTF("oversize packet, pkt_size is %d\n", pkt_size);
+        s->regs[SONIC_ISR] |= SONIC_ISR_RBAE;
+        dp8393x_update_irq(s);
+        dp8393x_do_read_rra(s);
+        return pkt_size;
+    }
+
     packet_type = dp8393x_receive_filter(s, buf, pkt_size);
     if (packet_type < 0) {
         DPRINTF("packet not for netcard\n");