numam-dpdk/lib/librte_gso/gso_udp4.c
Yi Yang c0d002aed9 gso: fix mbuf freeing responsibility
rte_gso_segment decreased refcnt of pkt by one, but
it is wrong if pkt is external mbuf, pkt won't be
freed because of incorrect refcnt, the result is
application can't allocate mbuf from mempool because
mbufs in mempool are run out of.

One correct way is application should call
rte_pktmbuf_free after calling rte_gso_segment to free
pkt explicitly. rte_gso_segment must not handle it, this
should be responsibility of application.

This commit changed rte_gso_segment in functional behavior
and return value, so the application must take appropriate
actions according to return values, "ret < 0" means it
should free and drop 'pkt', "ret == 0" means 'pkt' isn't
GSOed but 'pkt' can be transmitted as a normal packet,
"ret > 0" means 'pkt' has been GSOed into two or multiple
segments, it should use "pkts_out" to transmit these
segments. The application must free 'pkt' after call
rte_gso_segment when return value isn't equal to 0.

Fixes: 119583797b ("gso: support TCP/IPv4 GSO")
Cc: stable@dpdk.org

Signed-off-by: Yi Yang <yangyi01@inspur.com>
Acked-by: Jiayu Hu <jiayu.hu@intel.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
2020-11-03 22:45:02 +01:00

83 lines
2.1 KiB
C

/* SPDX-License-Identifier: BSD-3-Clause
* Copyright(c) 2018 Intel Corporation
*/
#include "gso_common.h"
#include "gso_udp4.h"
#define IPV4_HDR_MF_BIT (1U << 13)
static inline void
update_ipv4_udp_headers(struct rte_mbuf *pkt, struct rte_mbuf **segs,
uint16_t nb_segs)
{
struct rte_ipv4_hdr *ipv4_hdr;
uint16_t frag_offset = 0, is_mf;
uint16_t l2_hdrlen = pkt->l2_len, l3_hdrlen = pkt->l3_len;
uint16_t tail_idx = nb_segs - 1, length, i;
/*
* Update IP header fields for output segments. Specifically,
* keep the same IP id, update fragment offset and total
* length.
*/
for (i = 0; i < nb_segs; i++) {
ipv4_hdr = rte_pktmbuf_mtod_offset(segs[i],
struct rte_ipv4_hdr *, l2_hdrlen);
length = segs[i]->pkt_len - l2_hdrlen;
ipv4_hdr->total_length = rte_cpu_to_be_16(length);
is_mf = i < tail_idx ? IPV4_HDR_MF_BIT : 0;
ipv4_hdr->fragment_offset =
rte_cpu_to_be_16(frag_offset | is_mf);
frag_offset += ((length - l3_hdrlen) >> 3);
}
}
int
gso_udp4_segment(struct rte_mbuf *pkt,
uint16_t gso_size,
struct rte_mempool *direct_pool,
struct rte_mempool *indirect_pool,
struct rte_mbuf **pkts_out,
uint16_t nb_pkts_out)
{
struct rte_ipv4_hdr *ipv4_hdr;
uint16_t pyld_unit_size, hdr_offset;
uint16_t frag_off;
int ret;
/* Don't process the fragmented packet */
ipv4_hdr = rte_pktmbuf_mtod_offset(pkt, struct rte_ipv4_hdr *,
pkt->l2_len);
frag_off = rte_be_to_cpu_16(ipv4_hdr->fragment_offset);
if (unlikely(IS_FRAGMENTED(frag_off))) {
return 0;
}
/*
* UDP fragmentation is the same as IP fragmentation.
* Except the first one, other output packets just have l2
* and l3 headers.
*/
hdr_offset = pkt->l2_len + pkt->l3_len;
/* Don't process the packet without data. */
if (unlikely(hdr_offset + pkt->l4_len >= pkt->pkt_len)) {
return 0;
}
/* pyld_unit_size must be a multiple of 8 because frag_off
* uses 8 bytes as unit.
*/
pyld_unit_size = (gso_size - hdr_offset) & ~7U;
/* Segment the payload */
ret = gso_do_segment(pkt, hdr_offset, pyld_unit_size, direct_pool,
indirect_pool, pkts_out, nb_pkts_out);
if (ret > 1)
update_ipv4_udp_headers(pkt, pkts_out, ret);
return ret;
}