[ovs-dev] [PATCH v11 06/14] dp-packet: Handle multi-seg mbufs in helper funcs.
Ian Stokes
ian.stokes at intel.com
Mon Dec 17 20:07:19 UTC 2018
On 10/22/2018 3:30 PM, Stokes, Ian wrote:
>> Most helper functions in dp-packet assume that the data held by a
>> dp_packet is contiguous, and perform operations such as pointer arithmetic
>> under that assumption. However, with the introduction of multi-segment
>> mbufs, where data is non-contiguous, such assumptions are no longer
>> possible. Some examples of Such helper functions are dp_packet_tail(),
>> dp_packet_tailroom(), dp_packet_end(),
>> dp_packet_get_allocated() and dp_packet_at().
>>
>> Thus, instead of assuming contiguous data in dp_packet, they now iterate
>> over the (non-contiguous) data in mbufs to perform their calculations.
>>
>> Finally, dp_packet_use__() has also been modified to perform the
>> initialisation of the packet (and setting the source) before continuing to
>> set its size and data length, which now depends on the type of packet.
>>
>> Co-authored-by: Mark Kavanagh <mark.b.kavanagh at intel.com>
>>
>> Signed-off-by: Mark Kavanagh <mark.b.kavanagh at intel.com>
>> Signed-off-by: Tiago Lam <tiago.lam at intel.com>
>> Acked-by: Eelco Chaudron <echaudro at redhat.com>
>> Acked-by: Flavio Leitner <fbl at sysclose.org>
>
> Thanks for this Tiago,
>
> It looks ok on inspection, will need a rebase however in the next revision.
>
> Ian
>
Quick follow up on this Tiago, I spotted some errors introduced in
Travis after applying this patch (Note this was testing this series on
top of 35fe9ef ("dpif-netdev: Add vlan to mask for flow_put
operation.") as per the cover note.
https://travis-ci.org/istokes/ovs/jobs/469153535
https://travis-ci.org/istokes/ovs/jobs/469153543
These should be fixed during the rebase also.
Thanks
Ian
>> ---
>> lib/dp-packet.c | 4 +-
>> lib/dp-packet.h | 191
>> +++++++++++++++++++++++++++++++++++++++++++++++++++-----
>> 2 files changed, 177 insertions(+), 18 deletions(-)
>>
>> diff --git a/lib/dp-packet.c b/lib/dp-packet.c index 782e7c2..2aaeaae
>> 100644
>> --- a/lib/dp-packet.c
>> +++ b/lib/dp-packet.c
>> @@ -41,11 +41,11 @@ static void
>> dp_packet_use__(struct dp_packet *b, void *base, size_t allocated,
>> enum dp_packet_source source) {
>> + dp_packet_init__(b, allocated, source);
>> +
>> dp_packet_set_base(b, base);
>> dp_packet_set_data(b, base);
>> dp_packet_set_size(b, 0);
>> -
>> - dp_packet_init__(b, allocated, source);
>> }
>>
>> /* Initializes 'b' as an empty dp_packet that contains the 'allocated'
>> bytes of diff --git a/lib/dp-packet.h b/lib/dp-packet.h index
>> 223efe2..78c6f7f 100644
>> --- a/lib/dp-packet.h
>> +++ b/lib/dp-packet.h
>> @@ -133,6 +133,10 @@ static inline void *dp_packet_at(const struct
>> dp_packet *, size_t offset,
>> size_t size); static inline void
>> *dp_packet_at_assert(const struct dp_packet *,
>> size_t offset, size_t size);
>> +#ifdef DPDK_NETDEV
>> +static inline const struct rte_mbuf *
>> +dp_packet_mbuf_from_offset(const struct dp_packet *b, size_t *offset);
>> +#endif
>> static inline void *dp_packet_tail(const struct dp_packet *); static
>> inline void *dp_packet_end(const struct dp_packet *);
>>
>> @@ -185,9 +189,25 @@ dp_packet_delete(struct dp_packet *b) static inline
>> void * dp_packet_at(const struct dp_packet *b, size_t offset, size_t
>> size) {
>> - return offset + size <= dp_packet_size(b)
>> - ? (char *) dp_packet_data(b) + offset
>> - : NULL;
>> + if (offset + size > dp_packet_size(b)) {
>> + return NULL;
>> + }
>> +
>> +#ifdef DPDK_NETDEV
>> + if (b->source == DPBUF_DPDK) {
>> + struct rte_mbuf *buf = CONST_CAST(struct rte_mbuf *, &b->mbuf);
>> +
>> + while (buf && offset > buf->data_len) {
>> + offset -= buf->data_len;
>> +
>> + buf = buf->next;
>> + }
>> +
>> + return buf ? rte_pktmbuf_mtod_offset(buf, char *, offset) : NULL;
>> + }
>> +#endif
>> +
>> + return (char *) dp_packet_data(b) + offset;
>> }
>>
>> /* Returns a pointer to byte 'offset' in 'b', which must contain at least
>> @@ -196,13 +216,23 @@ static inline void * dp_packet_at_assert(const
>> struct dp_packet *b, size_t offset, size_t size) {
>> ovs_assert(offset + size <= dp_packet_size(b));
>> - return ((char *) dp_packet_data(b)) + offset;
>> + return dp_packet_at(b, offset, size);
>> }
>>
>> /* Returns a pointer to byte following the last byte of data in use in
>> 'b'. */ static inline void * dp_packet_tail(const struct dp_packet *b)
>> {
>> +#ifdef DPDK_NETDEV
>> + if (b->source == DPBUF_DPDK) {
>> + struct rte_mbuf *buf = CONST_CAST(struct rte_mbuf *, &b->mbuf);
>> + /* Find last segment where data ends, meaning the tail of the
>> chained
>> + * mbufs must be there */
>> + buf = rte_pktmbuf_lastseg(buf);
>> +
>> + return rte_pktmbuf_mtod_offset(buf, void *, buf->data_len);
>> + }
>> +#endif
>> return (char *) dp_packet_data(b) + dp_packet_size(b); }
>>
>> @@ -211,6 +241,15 @@ dp_packet_tail(const struct dp_packet *b) static
>> inline void * dp_packet_end(const struct dp_packet *b) {
>> +#ifdef DPDK_NETDEV
>> + if (b->source == DPBUF_DPDK) {
>> + struct rte_mbuf *buf = CONST_CAST(struct rte_mbuf *,
>> +&(b->mbuf));
>> +
>> + buf = rte_pktmbuf_lastseg(buf);
>> +
>> + return (char *) buf->buf_addr + buf->buf_len;
>> + }
>> +#endif
>> return (char *) dp_packet_base(b) + dp_packet_get_allocated(b); }
>>
>> @@ -236,6 +275,15 @@ dp_packet_tailroom(const struct dp_packet *b) static
>> inline void dp_packet_clear(struct dp_packet *b) {
>> +#ifdef DPDK_NETDEV
>> + if (b->source == DPBUF_DPDK) {
>> + /* sets pkt_len and data_len to zero and frees unused mbufs */
>> + dp_packet_set_size(b, 0);
>> + rte_pktmbuf_reset(&b->mbuf);
>> +
>> + return;
>> + }
>> +#endif
>> dp_packet_set_data(b, dp_packet_base(b));
>> dp_packet_set_size(b, 0);
>> }
>> @@ -248,28 +296,47 @@ dp_packet_pull(struct dp_packet *b, size_t size)
>> void *data = dp_packet_data(b);
>> ovs_assert(dp_packet_size(b) - dp_packet_l2_pad_size(b) >= size);
>> dp_packet_set_data(b, (char *) dp_packet_data(b) + size);
>> - dp_packet_set_size(b, dp_packet_size(b) - size);
>> +#ifdef DPDK_NETDEV
>> + b->mbuf.pkt_len -= size;
>> +#else
>> + b->size_ -= size;
>> +#endif
>> +
>> return data;
>> }
>>
>> +#ifdef DPDK_NETDEV
>> +/* Similar to dp_packet_try_pull() but doesn't actually pull any data,
>> +only
>> + * checks if it could and returns true or false accordingly.
>> + *
>> + * Valid for dp_packets carrying mbufs only. */ static inline bool
>> +dp_packet_mbuf_may_pull(const struct dp_packet *b, size_t size) {
>> + if (size > b->mbuf.data_len) {
>> + return false;
>> + }
>> +
>> + return true;
>> +}
>> +#endif
>> +
>> /* If 'b' has at least 'size' bytes of data, removes that many bytes from
>> the
>> * head end of 'b' and returns the first byte removed. Otherwise,
>> returns a
>> * null pointer without modifying 'b'. */ static inline void *
>> dp_packet_try_pull(struct dp_packet *b, size_t size) {
>> +#ifdef DPDK_NETDEV
>> + if (!dp_packet_mbuf_may_pull(b, size)) {
>> + return NULL;
>> + }
>> +#endif
>> +
>> return dp_packet_size(b) - dp_packet_l2_pad_size(b) >= size
>> ? dp_packet_pull(b, size) : NULL; }
>>
>> static inline bool
>> -dp_packet_equal(const struct dp_packet *a, const struct dp_packet *b) -{
>> - return dp_packet_size(a) == dp_packet_size(b) &&
>> - !memcmp(dp_packet_data(a), dp_packet_data(b),
>> dp_packet_size(a));
>> -}
>> -
>> -static inline bool
>> dp_packet_is_eth(const struct dp_packet *b) {
>> return b->packet_type == htonl(PT_ETH); @@ -311,6 +378,12 @@
>> dp_packet_set_l2_pad_size(struct dp_packet *b, uint8_t pad_size) static
>> inline void * dp_packet_l2_5(const struct dp_packet *b) {
>> +#ifdef DPDK_NETDEV
>> + if (!dp_packet_mbuf_may_pull(b, b->l2_5_ofs)) {
>> + return NULL;
>> + }
>> +#endif
>> +
>> return b->l2_5_ofs != UINT16_MAX
>> ? (char *) dp_packet_data(b) + b->l2_5_ofs
>> : NULL;
>> @@ -327,6 +400,12 @@ dp_packet_set_l2_5(struct dp_packet *b, void *l2_5)
>> static inline void * dp_packet_l3(const struct dp_packet *b) {
>> +#ifdef DPDK_NETDEV
>> + if (!dp_packet_mbuf_may_pull(b, b->l3_ofs)) {
>> + return NULL;
>> + }
>> +#endif
>> +
>> return b->l3_ofs != UINT16_MAX
>> ? (char *) dp_packet_data(b) + b->l3_ofs
>> : NULL;
>> @@ -341,6 +420,12 @@ dp_packet_set_l3(struct dp_packet *b, void *l3)
>> static inline void * dp_packet_l4(const struct dp_packet *b) {
>> +#ifdef DPDK_NETDEV
>> + if (!dp_packet_mbuf_may_pull(b, b->l4_ofs)) {
>> + return NULL;
>> + }
>> +#endif
>> +
>> return b->l4_ofs != UINT16_MAX
>> ? (char *) dp_packet_data(b) + b->l4_ofs
>> : NULL;
>> @@ -355,6 +440,27 @@ dp_packet_set_l4(struct dp_packet *b, void *l4)
>> static inline size_t dp_packet_l4_size(const struct dp_packet *b) {
>> +#ifdef DPDK_NETDEV
>> + if (b->source == DPBUF_DPDK) {
>> + if (!dp_packet_mbuf_may_pull(b, b->l4_ofs)) {
>> + return 0;
>> + }
>> +
>> + struct rte_mbuf *mbuf = CONST_CAST(struct rte_mbuf *, &b->mbuf);
>> + size_t l4_size = mbuf->data_len - b->l4_ofs;
>> +
>> + mbuf = mbuf->next;
>> + while (mbuf) {
>> + l4_size += mbuf->data_len;
>> +
>> + mbuf = mbuf->next;
>> + }
>> +
>> + l4_size -= dp_packet_l2_pad_size(b);
>> +
>> + return l4_size;
>> + }
>> +#endif
>> return b->l4_ofs != UINT16_MAX
>> ? (const char *)dp_packet_tail(b) - (const char *)dp_packet_l4(b)
>> - dp_packet_l2_pad_size(b)
>> @@ -408,6 +514,53 @@ dp_packet_get_nd_payload(const struct dp_packet *b)
>> #ifdef DPDK_NETDEV BUILD_ASSERT_DECL(offsetof(struct dp_packet, mbuf) ==
>> 0);
>>
>> +static inline const struct rte_mbuf *
>> +dp_packet_mbuf_from_offset(const struct dp_packet *b, size_t *offset) {
>> + const struct rte_mbuf *mbuf = &b->mbuf;
>> + while (mbuf && *offset >= mbuf->data_len) {
>> + *offset -= mbuf->data_len;
>> +
>> + mbuf = mbuf->next;
>> + }
>> +
>> + return mbuf;
>> +}
>> +
>> +static inline bool
>> +dp_packet_equal(const struct dp_packet *a, const struct dp_packet *b) {
>> + if (dp_packet_size(a) != dp_packet_size(b)) {
>> + return false;
>> + }
>> +
>> + const struct rte_mbuf *m_a, *m_b;
>> + size_t abs_off_a = 0;
>> + size_t abs_off_b = 0;
>> + size_t len = 0;
>> + while (m_a != NULL && m_b != NULL) {
>> + size_t rel_off_a = abs_off_a;
>> + size_t rel_off_b = abs_off_b;
>> + m_a = dp_packet_mbuf_from_offset(a, &rel_off_a);
>> + m_b = dp_packet_mbuf_from_offset(b, &rel_off_b);
>> + if (!m_a || !m_b) {
>> + break;
>> + }
>> +
>> + len = MIN(m_a->data_len - rel_off_a, m_b->data_len -
>> + rel_off_b);
>> +
>> + if (memcmp(rte_pktmbuf_mtod_offset(m_a, char *, rel_off_a),
>> + rte_pktmbuf_mtod_offset(m_b, char *, rel_off_b),
>> + len)) {
>> + return false;
>> + }
>> +
>> + abs_off_a += len;
>> + abs_off_b += len;
>> + }
>> +
>> + return (!m_a && !m_b) ? true : false; }
>> +
>> static inline void *
>> dp_packet_base(const struct dp_packet *b) { @@ -516,7 +669,7 @@
>> __packet_set_data(struct dp_packet *b, uint16_t v) static inline uint16_t
>> dp_packet_get_allocated(const struct dp_packet *b) {
>> - return b->mbuf.buf_len;
>> + return b->mbuf.nb_segs * b->mbuf.buf_len;
>> }
>>
>> static inline void
>> @@ -525,6 +678,13 @@ dp_packet_set_allocated(struct dp_packet *b, uint16_t
>> s)
>> b->mbuf.buf_len = s;
>> }
>> #else
>> +static inline bool
>> +dp_packet_equal(const struct dp_packet *a, const struct dp_packet *b) {
>> + return dp_packet_size(a) == dp_packet_size(b) &&
>> + !memcmp(dp_packet_data(a), dp_packet_data(b),
>> +dp_packet_size(a)); }
>> +
>> static inline void *
>> dp_packet_base(const struct dp_packet *b) { @@ -626,10 +786,9 @@
>> dp_packet_set_data(struct dp_packet *b, void *data) }
>>
>> static inline void
>> -dp_packet_reset_packet(struct dp_packet *b, int off)
>> +dp_packet_reset_packet(struct dp_packet *b, size_t off)
>> {
>> - dp_packet_set_size(b, dp_packet_size(b) - off);
>> - dp_packet_set_data(b, ((unsigned char *) dp_packet_data(b) + off));
>> + dp_packet_try_pull(b, off);
>> dp_packet_reset_offsets(b);
>> }
>>
>> --
>> 2.7.4
>
> _______________________________________________
> dev mailing list
> dev at openvswitch.org
> https://mail.openvswitch.org/mailman/listinfo/ovs-dev
>
More information about the dev
mailing list