Use packet_data() and extract headers using IOV_REMOVE_HEADER()
and IOV_PEEK_HEADER() rather than packet_get().
Signed-off-by: Laurent Vivier <lvivier(a)redhat.com>
---
dhcp.c | 45 +++++++++++++++++++++++++++------------------
1 file changed, 27 insertions(+), 18 deletions(-)
diff --git a/dhcp.c b/dhcp.c
index b0de04be6f27..e8408ef04839 100644
--- a/dhcp.c
+++ b/dhcp.c
@@ -302,27 +302,33 @@ static void opt_set_dns_search(const struct ctx *c, size_t max_len)
*/
int dhcp(const struct ctx *c, const struct pool *p)
{
- size_t mlen, dlen, offset = 0, opt_len, opt_off = 0;
+ size_t mlen, dlen, opt_len;
char macstr[ETH_ADDRSTRLEN];
struct in_addr mask, dst;
const struct ethhdr *eh;
const struct iphdr *iph;
const struct udphdr *uh;
+ struct iov_tail data;
struct msg const *m;
+ struct msg mc;
+ struct ethhdr ehc;
+ struct iphdr iphc;
+ struct udphdr uhc;
struct msg reply;
unsigned int i;
- eh = packet_get(p, 0, offset, sizeof(*eh), NULL);
- offset += sizeof(*eh);
+ if (!packet_data(p, 0, &data))
+ return -1;
- iph = packet_get(p, 0, offset, sizeof(*iph), NULL);
+ eh = IOV_REMOVE_HEADER(&data, ehc);
+ iph = IOV_PEEK_HEADER(&data, iphc);
if (!eh || !iph)
return -1;
- offset += iph->ihl * 4UL;
- uh = packet_get(p, 0, offset, sizeof(*uh), &mlen);
- offset += sizeof(*uh);
+ if (!iov_tail_drop(&data, iph->ihl * 4UL))
+ return -1;
+ uh = IOV_REMOVE_HEADER(&data, uhc);
if (!uh)
return -1;
@@ -332,7 +338,9 @@ int dhcp(const struct ctx *c, const struct pool *p)
if (c->no_dhcp)
return 1;
- m = packet_get(p, 0, offset, offsetof(struct msg, o), &opt_len);
+ mlen = iov_tail_size(&data);
+ m = (struct msg const *)iov_remove_header_(&data, &mc, offsetof(struct msg, o),
+ __alignof__(struct msg));
if (!m ||
mlen != ntohs(uh->len) - sizeof(*uh) ||
mlen < offsetof(struct msg, o) ||
@@ -355,27 +363,28 @@ int dhcp(const struct ctx *c, const struct pool *p)
memset(&reply.file, 0, sizeof(reply.file));
reply.magic = m->magic;
- offset += offsetof(struct msg, o);
-
for (i = 0; i < ARRAY_SIZE(opts); i++)
opts[i].clen = -1;
- while (opt_off + 2 < opt_len) {
- const uint8_t *olen, *val;
+ opt_len = iov_tail_size(&data);
+ while (opt_len >= 2) {
+ uint8_t olenc, typec;
+ const uint8_t *olen;
uint8_t *type;
- type = packet_get(p, 0, offset + opt_off, 1, NULL);
- olen = packet_get(p, 0, offset + opt_off + 1, 1, NULL);
+ type = IOV_REMOVE_HEADER(&data, typec);
+ olen = IOV_REMOVE_HEADER(&data, olenc);
if (!type || !olen)
return -1;
- val = packet_get(p, 0, offset + opt_off + 2, *olen, NULL);
- if (!val)
+ opt_len = iov_tail_size(&data);
+ if (opt_len < *olen)
return -1;
- memcpy(&opts[*type].c, val, *olen);
+ iov_to_buf(&data.iov[0], data.cnt, data.off, &opts[*type].c, *olen);
opts[*type].clen = *olen;
- opt_off += *olen + 2;
+ iov_tail_drop(&data, *olen);
+ opt_len -= *olen;
}
opts[80].slen = -1;
--
2.49.0