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authorDenys Vlasenko <vda.linux@googlemail.com>2014-02-19 13:17:11 (GMT)
committer Denys Vlasenko <vda.linux@googlemail.com>2014-02-19 13:17:11 (GMT)
commitffc3a93d0dbf4ac887f528c0495cd586a092d88f (patch)
tree6d8d51a7cbd435d3e2a22a34f620770968c6c2b6
parent50e4cc29f56b5401579cddaf42d0404320b9efa7 (diff)
downloadbusybox-ffc3a93d0dbf4ac887f528c0495cd586a092d88f.tar.gz
busybox-ffc3a93d0dbf4ac887f528c0495cd586a092d88f.tar.bz2
udhcpc: fix BPF filter. Hopefully fixes the root cause of 4598 and 6746
Use a *signed* large positive value in BPF filter to indicate success. Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--networking/udhcp/d6_dhcpc.c2
-rw-r--r--networking/udhcp/dhcpc.c7
2 files changed, 5 insertions, 4 deletions
diff --git a/networking/udhcp/d6_dhcpc.c b/networking/udhcp/d6_dhcpc.c
index b0f0798..044f046 100644
--- a/networking/udhcp/d6_dhcpc.c
+++ b/networking/udhcp/d6_dhcpc.c
@@ -711,7 +711,7 @@ static int d6_raw_socket(int ifindex)
/* jump to L3 if udp dport is CLIENT_PORT6, else to L4 */
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 68, 0, 1),
/* L3: accept packet */
- BPF_STMT(BPF_RET|BPF_K, 0xffffffff),
+ BPF_STMT(BPF_RET|BPF_K, 0x7fffffff),
/* L4: discard packet */
BPF_STMT(BPF_RET|BPF_K, 0),
};
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index bdb1e2b..25f18b3 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -1025,9 +1025,10 @@ static int udhcp_raw_socket(int ifindex)
BPF_STMT(BPF_LD|BPF_H|BPF_IND, 2),
/* jump to L3 if udp dport is CLIENT_PORT, else to L4 */
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 68, 0, 1),
- /* L3: accept packet */
- BPF_STMT(BPF_RET|BPF_K, 0xffffffff),
- /* L4: discard packet */
+ /* L3: accept packet ("accept 0x7fffffff bytes") */
+ /* Accepting 0xffffffff works too but kernel 2.6.19 is buggy */
+ BPF_STMT(BPF_RET|BPF_K, 0x7fffffff),
+ /* L4: discard packet ("accept zero bytes") */
BPF_STMT(BPF_RET|BPF_K, 0),
};
static const struct sock_fprog filter_prog = {