On Wed, Apr 02, 2025 at 07:23:40PM +0200, Laurent Vivier wrote:Use packet_base() 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 | 38 ++++++++++++++++++++++---------------- iov.c | 1 - 2 files changed, 22 insertions(+), 17 deletions(-) diff --git a/dhcp.c b/dhcp.c index b0de04be6f27..f3167beb18b7 100644 --- a/dhcp.c +++ b/dhcp.c @@ -302,27 +302,32 @@ 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, opt_off = 0; 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_base(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); + data.off += iph->ihl * 4UL;iov_drop().+ uh = IOV_REMOVE_HEADER(&data, uhc); if (!uh) return -1; @@ -332,7 +337,9 @@ 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) || @@ -355,25 +362,24 @@ 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; + opt_len = iov_tail_size(&data); while (opt_off + 2 < opt_len) { - const uint8_t *olen, *val; + 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_tail_ptr(&data, opt_off, 1); + olen = iov_tail_ptr(&data, opt_off + 1, 1);I think you can and should use remove_header() for this as well.if (!type || !olen) return -1; - val = packet_get(p, 0, offset + opt_off + 2, *olen, NULL); - if (!val) + if (iov_tail_size(&data) < opt_off + 2 + *olen) return -1; - memcpy(&opts[*type].c, val, *olen); + iov_to_buf(&data.iov[0], data.cnt, data.off + opt_off + 2, + &opts[*type].c, *olen); opts[*type].clen = *olen; opt_off += *olen + 2; } diff --git a/iov.c b/iov.c index 0c69379316aa..66f15585a61a 100644 --- a/iov.c +++ b/iov.c @@ -253,7 +253,6 @@ bool iov_drop(struct iov_tail *tail, size_t len) * Returns: pointer to the data in the tail, NULL if the * tail doesn't contains @len bytes. */ -/* cppcheck-suppress unusedFunction */ void *iov_tail_ptr(struct iov_tail *tail, size_t off, size_t len) { const struct iovec *iov;-- David Gibson (he or they) | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you, not the other way | around. http://www.ozlabs.org/~dgibson