Currently, we have repeated code to check the received mergeable buffer's
length with allocated size. This commit creates a helper to do that and
converts current code to use it.
Signed-off-by: Bui Quang Minh <minhquangbu...@gmail.com>
---
drivers/net/virtio_net.c | 68 +++++++++++++++++-----------------------
1 file changed, 29 insertions(+), 39 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 6f9fedad4a5e..844cb2a78be0 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -778,6 +778,26 @@ static unsigned int mergeable_ctx_to_truesize(void
*mrg_ctx)
return (unsigned long)mrg_ctx & ((1 << MRG_CTX_HEADER_SHIFT) - 1);
}
+static int check_mergeable_len(struct net_device *dev, void *mrg_ctx,
+ unsigned int len)
+{
+ unsigned int headroom, tailroom, room, truesize;
+
+ truesize = mergeable_ctx_to_truesize(mrg_ctx);
+ headroom = mergeable_ctx_to_headroom(mrg_ctx);
+ tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
+ room = SKB_DATA_ALIGN(headroom + tailroom);
+
+ if (len > truesize - room) {
+ pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
+ dev->name, len, (unsigned long)(truesize - room));
+ DEV_STATS_INC(dev, rx_length_errors);
+ return -1;
+ }
+
+ return 0;
+}
+
static struct sk_buff *virtnet_build_skb(void *buf, unsigned int buflen,
unsigned int headroom,
unsigned int len)
@@ -1819,8 +1839,7 @@ static struct page *xdp_linearize_page(struct net_device
*dev,
page_off += *len;
while (--*num_buf) {
- unsigned int headroom, tailroom, room;
- unsigned int truesize, buflen;
+ unsigned int buflen;
void *buf;
void *ctx;
int off;
@@ -1832,17 +1851,8 @@ static struct page *xdp_linearize_page(struct net_device
*dev,
p = virt_to_head_page(buf);
off = buf - page_address(p);
- truesize = mergeable_ctx_to_truesize(ctx);
- headroom = mergeable_ctx_to_headroom(ctx);
- tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
- room = SKB_DATA_ALIGN(headroom + tailroom);
-
- if (unlikely(buflen > truesize - room)) {
+ if (check_mergeable_len(dev, ctx, buflen)) {
put_page(p);
- pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
- dev->name, buflen,
- (unsigned long)(truesize - room));
- DEV_STATS_INC(dev, rx_length_errors);
goto err_buf;
}
@@ -2143,7 +2153,6 @@ static int virtnet_build_xdp_buff_mrg(struct net_device
*dev,
struct virtnet_rq_stats *stats)
{
struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
- unsigned int headroom, tailroom, room;
struct skb_shared_info *shinfo;
unsigned int xdp_frags_truesz = 0;
unsigned int truesize;
@@ -2189,20 +2198,14 @@ static int virtnet_build_xdp_buff_mrg(struct net_device
*dev,
page = virt_to_head_page(buf);
offset = buf - page_address(page);
- truesize = mergeable_ctx_to_truesize(ctx);
- headroom = mergeable_ctx_to_headroom(ctx);
- tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
- room = SKB_DATA_ALIGN(headroom + tailroom);
-
- xdp_frags_truesz += truesize;
- if (unlikely(len > truesize - room)) {
+ if (check_mergeable_len(dev, ctx, len)) {
put_page(page);
- pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
- dev->name, len, (unsigned long)(truesize -
room));
- DEV_STATS_INC(dev, rx_length_errors);
goto err;
}
+ truesize = mergeable_ctx_to_truesize(ctx);
+ xdp_frags_truesz += truesize;
+
frag = &shinfo->frags[shinfo->nr_frags++];
skb_frag_fill_page_desc(frag, page, offset, len);
if (page_is_pfmemalloc(page))
@@ -2416,18 +2419,12 @@ static struct sk_buff *receive_mergeable(struct
net_device *dev,
struct sk_buff *head_skb, *curr_skb;
unsigned int truesize = mergeable_ctx_to_truesize(ctx);
unsigned int headroom = mergeable_ctx_to_headroom(ctx);
- unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
- unsigned int room = SKB_DATA_ALIGN(headroom + tailroom);
head_skb = NULL;
u64_stats_add(&stats->bytes, len - vi->hdr_len);
- if (unlikely(len > truesize - room)) {
- pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
- dev->name, len, (unsigned long)(truesize - room));
- DEV_STATS_INC(dev, rx_length_errors);
+ if (check_mergeable_len(dev, ctx, len))
goto err_skb;
- }
if (unlikely(vi->xdp_enabled)) {
struct bpf_prog *xdp_prog;
@@ -2462,17 +2459,10 @@ static struct sk_buff *receive_mergeable(struct
net_device *dev,
u64_stats_add(&stats->bytes, len);
page = virt_to_head_page(buf);
- truesize = mergeable_ctx_to_truesize(ctx);
- headroom = mergeable_ctx_to_headroom(ctx);
- tailroom = headroom ? sizeof(struct skb_shared_info) : 0;
- room = SKB_DATA_ALIGN(headroom + tailroom);
- if (unlikely(len > truesize - room)) {
- pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
- dev->name, len, (unsigned long)(truesize -
room));
- DEV_STATS_INC(dev, rx_length_errors);
+ if (check_mergeable_len(dev, ctx, len))
goto err_skb;
- }
+ truesize = mergeable_ctx_to_truesize(ctx);
curr_skb = virtnet_skb_append_frag(head_skb, curr_skb, page,
buf, len, truesize);
if (!curr_skb)
--
2.43.0
