The dp_packet_put*() function - dp_packet_put_uninit(), dp_packet_put() and dp_packet_put_zeros() - are, in their current implementation, operating on the data buffer of a dp_packet as if it were contiguous, which in the case of multi-segment mbufs means they operate on the first mbuf in the chain. However, in the case of dp_packet_put_uninit(), for example, it is the data length of the last mbuf in the mbuf chain that should be adjusted. These functions have thus been modified to support multi-segment mbufs.
Additionally, most of the core logic in dp_pcket_put_uninit() was moved to a new helper function, dp_packet_put_uninit()_, to abstract the implementation details from the API, since in the case of multi-seg mbufs a new struct is returned that holds the mbuf and offset that constitute the tail. For the single mbuf case a pointer to the byte that constitute the tail still returned. Co-authored-by: Mark Kavanagh <mark.b.kavan...@intel.com> Signed-off-by: Mark Kavanagh <mark.b.kavan...@intel.com> Signed-off-by: Tiago Lam <tiago....@intel.com> --- lib/dp-packet.c | 98 +++++++++++++++++++++++++++++++++++++++++++++++++-------- lib/dp-packet.h | 7 +++++ 2 files changed, 92 insertions(+), 13 deletions(-) diff --git a/lib/dp-packet.c b/lib/dp-packet.c index 782e7c2..eefde37 100644 --- a/lib/dp-packet.c +++ b/lib/dp-packet.c @@ -312,27 +312,67 @@ dp_packet_shift(struct dp_packet *b, int delta) } } -/* Appends 'size' bytes of data to the tail end of 'b', reallocating and - * copying its data if necessary. Returns a pointer to the first byte of the - * new data, which is left uninitialized. */ -void * -dp_packet_put_uninit(struct dp_packet *b, size_t size) +static void * +dp_packet_put_uninit_(struct dp_packet *b, size_t size) { void *p; dp_packet_prealloc_tailroom(b, size); +#ifdef DPDK_NETDEV + p = dp_packet_mbuf_tail(b); + /* In the case of multi-segment mbufs, the data length of the last mbuf + * should be adjusted by 'size' bytes. The packet length of the entire + * mbuf chain (stored in the first mbuf of said chain) is adjusted in + * the normal execution path below. + */ + + struct rte_mbuf *tmbuf = (struct rte_mbuf *) p; + struct mbuf_tail *mbuf_tail = xmalloc(sizeof(*mbuf_tail)); + size_t pkt_len = size; + + mbuf_tail->mbuf = tmbuf; + mbuf_tail->ofs = tmbuf->data_len; + + /* Adjust size of intermediate mbufs from current tail to end */ + while (tmbuf && pkt_len > 0) { + tmbuf->data_len = MIN(pkt_len, (rte_pktmbuf_mtod(tmbuf, char *) + + tmbuf->buf_len) - rte_pktmbuf_mtod(tmbuf, char *)); + pkt_len -= tmbuf->data_len; + + tmbuf = tmbuf->next; + } + + p = (void *) mbuf_tail; +#else p = dp_packet_tail(b); +#endif dp_packet_set_size(b, dp_packet_size(b) + size); + return p; } -/* Appends 'size' zeroed bytes to the tail end of 'b'. Data in 'b' is - * reallocated and copied if necessary. Returns a pointer to the first byte of - * the data's location in the dp_packet. */ +static void * +dp_packet_tail_to_addr(struct dp_packet *b OVS_UNUSED, void *p) { +#ifdef DPDK_NETDEV + struct mbuf_tail *mbuf_tail = (struct mbuf_tail *) p; + p = (void *) rte_pktmbuf_mtod_offset(mbuf_tail->mbuf, void *, + mbuf_tail->ofs); +#endif + + return p; +} + +/* Appends 'size' bytes of data to the tail end of 'b', reallocating and + * copying its data if necessary. Returns a pointer to the first byte of the + * new data, which is left uninitialized. */ void * -dp_packet_put_zeros(struct dp_packet *b, size_t size) +dp_packet_put_uninit(struct dp_packet *b, size_t size) { - void *dst = dp_packet_put_uninit(b, size); - memset(dst, 0, size); + void *tail = dp_packet_put_uninit_(b, size); + + void *dst = dp_packet_tail_to_addr(b, tail); + + free(tail); + return dst; } @@ -342,8 +382,40 @@ dp_packet_put_zeros(struct dp_packet *b, size_t size) void * dp_packet_put(struct dp_packet *b, const void *p, size_t size) { - void *dst = dp_packet_put_uninit(b, size); - memcpy(dst, p, size); + void *tail = dp_packet_put_uninit_(b, size); +#ifdef DPDK_NETDEV + struct mbuf_tail *mbuf_tail = (struct mbuf_tail *) tail; + + dp_packet_mbuf_write(mbuf_tail->mbuf, mbuf_tail->ofs, size, p); +#else + memcpy(tail, p, size); +#endif + + void *dst = dp_packet_tail_to_addr(b, tail); + + free(tail); + + return dst; +} + +/* Appends 'size' zeroed bytes to the tail end of 'b'. Data in 'b' is + * reallocated and copied if necessary. Returns a pointer to the first byte of + * the data's location in the dp_packet. */ +void * +dp_packet_put_zeros(struct dp_packet *b, size_t size) +{ + void *dst; +#ifdef DPDK_NETDEV + char zeros[size]; + memset(zeros, 0, size); + + dst = dp_packet_put(b, zeros, size); + + return dst; +#endif + dst = dp_packet_put_uninit(b, size); + memset(dst, 0, size); + return dst; } diff --git a/lib/dp-packet.h b/lib/dp-packet.h index 35ee6df..fcfa2d6 100644 --- a/lib/dp-packet.h +++ b/lib/dp-packet.h @@ -80,6 +80,13 @@ struct dp_packet { }; }; +#ifdef DPDK_NETDEV +struct mbuf_tail { + struct rte_mbuf *mbuf; + uint16_t ofs; +}; +#endif + static inline void *dp_packet_data(const struct dp_packet *); static inline void dp_packet_set_data(struct dp_packet *, void *); static inline void *dp_packet_base(const struct dp_packet *); -- 2.7.4 _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev