can: gw: Use nla_policy to validate netlink attributes
Also use nla_get_u32() instead of nla_memcpy() to access u32 attribtues.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
diff --git a/net/can/gw.c b/net/can/gw.c
index a3ff980..a1c639c 100644
--- a/net/can/gw.c
+++ b/net/can/gw.c
@@ -558,6 +558,18 @@
return skb->len;
}
+static const struct nla_policy cgw_policy[CGW_MAX+1] = {
+ [CGW_MOD_AND] = { .len = sizeof(struct cgw_frame_mod) },
+ [CGW_MOD_OR] = { .len = sizeof(struct cgw_frame_mod) },
+ [CGW_MOD_XOR] = { .len = sizeof(struct cgw_frame_mod) },
+ [CGW_MOD_SET] = { .len = sizeof(struct cgw_frame_mod) },
+ [CGW_CS_XOR] = { .len = sizeof(struct cgw_csum_xor) },
+ [CGW_CS_CRC8] = { .len = sizeof(struct cgw_csum_crc8) },
+ [CGW_SRC_IF] = { .type = NLA_U32 },
+ [CGW_DST_IF] = { .type = NLA_U32 },
+ [CGW_FILTER] = { .len = sizeof(struct can_filter) },
+};
+
/* check for common and gwtype specific attributes */
static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod,
u8 gwtype, void *gwtypeattr)
@@ -570,14 +582,14 @@
/* initialize modification & checksum data space */
memset(mod, 0, sizeof(*mod));
- err = nlmsg_parse(nlh, sizeof(struct rtcanmsg), tb, CGW_MAX, NULL);
+ err = nlmsg_parse(nlh, sizeof(struct rtcanmsg), tb, CGW_MAX,
+ cgw_policy);
if (err < 0)
return err;
/* check for AND/OR/XOR/SET modifications */
- if (tb[CGW_MOD_AND] &&
- nla_len(tb[CGW_MOD_AND]) == CGW_MODATTR_LEN) {
+ if (tb[CGW_MOD_AND]) {
nla_memcpy(&mb, tb[CGW_MOD_AND], CGW_MODATTR_LEN);
canframecpy(&mod->modframe.and, &mb.cf);
@@ -593,8 +605,7 @@
mod->modfunc[modidx++] = mod_and_data;
}
- if (tb[CGW_MOD_OR] &&
- nla_len(tb[CGW_MOD_OR]) == CGW_MODATTR_LEN) {
+ if (tb[CGW_MOD_OR]) {
nla_memcpy(&mb, tb[CGW_MOD_OR], CGW_MODATTR_LEN);
canframecpy(&mod->modframe.or, &mb.cf);
@@ -610,8 +621,7 @@
mod->modfunc[modidx++] = mod_or_data;
}
- if (tb[CGW_MOD_XOR] &&
- nla_len(tb[CGW_MOD_XOR]) == CGW_MODATTR_LEN) {
+ if (tb[CGW_MOD_XOR]) {
nla_memcpy(&mb, tb[CGW_MOD_XOR], CGW_MODATTR_LEN);
canframecpy(&mod->modframe.xor, &mb.cf);
@@ -627,8 +637,7 @@
mod->modfunc[modidx++] = mod_xor_data;
}
- if (tb[CGW_MOD_SET] &&
- nla_len(tb[CGW_MOD_SET]) == CGW_MODATTR_LEN) {
+ if (tb[CGW_MOD_SET]) {
nla_memcpy(&mb, tb[CGW_MOD_SET], CGW_MODATTR_LEN);
canframecpy(&mod->modframe.set, &mb.cf);
@@ -647,9 +656,7 @@
/* check for checksum operations after CAN frame modifications */
if (modidx) {
- if (tb[CGW_CS_CRC8] &&
- nla_len(tb[CGW_CS_CRC8]) == CGW_CS_CRC8_LEN) {
-
+ if (tb[CGW_CS_CRC8]) {
struct cgw_csum_crc8 *c = (struct cgw_csum_crc8 *)\
nla_data(tb[CGW_CS_CRC8]);
@@ -674,9 +681,7 @@
mod->csumfunc.crc8 = cgw_csum_crc8_neg;
}
- if (tb[CGW_CS_XOR] &&
- nla_len(tb[CGW_CS_XOR]) == CGW_CS_XOR_LEN) {
-
+ if (tb[CGW_CS_XOR]) {
struct cgw_csum_xor *c = (struct cgw_csum_xor *)\
nla_data(tb[CGW_CS_XOR]);
@@ -710,8 +715,7 @@
memset(ccgw, 0, sizeof(*ccgw));
/* check for can_filter in attributes */
- if (tb[CGW_FILTER] &&
- nla_len(tb[CGW_FILTER]) == sizeof(struct can_filter))
+ if (tb[CGW_FILTER])
nla_memcpy(&ccgw->filter, tb[CGW_FILTER],
sizeof(struct can_filter));
@@ -721,13 +725,8 @@
if (!tb[CGW_SRC_IF] || !tb[CGW_DST_IF])
return err;
- if (nla_len(tb[CGW_SRC_IF]) == sizeof(u32))
- nla_memcpy(&ccgw->src_idx, tb[CGW_SRC_IF],
- sizeof(u32));
-
- if (nla_len(tb[CGW_DST_IF]) == sizeof(u32))
- nla_memcpy(&ccgw->dst_idx, tb[CGW_DST_IF],
- sizeof(u32));
+ ccgw->src_idx = nla_get_u32(tb[CGW_SRC_IF]);
+ ccgw->dst_idx = nla_get_u32(tb[CGW_DST_IF]);
/* both indices set to 0 for flushing all routing entries */
if (!ccgw->src_idx && !ccgw->dst_idx)