In its current implementation dp_packet_shift() is also unaware of
multi-seg mbufs (that holds data in memory non-contiguously) and
assumes
that data exists contiguously in memory, memmove'ing data to perform
the
shift.
To add support for multi-seg mbuds a new set of functions was
introduced, dp_packet_mbuf_shift() and dp_packet_mbuf_write(). These
functions are used by dp_packet_shift(), when handling multi-seg
mbufs,
to shift and write data within a chain of mbufs.
Signed-off-by: Tiago Lam <[email protected]>
---
lib/dp-packet.c | 102
++++++++++++++++++++++++++++++++++++++++++++++++++++++++
lib/dp-packet.h | 8 +++++
2 files changed, 110 insertions(+)
diff --git a/lib/dp-packet.c b/lib/dp-packet.c
index 9f8503e..399fadb 100644
--- a/lib/dp-packet.c
+++ b/lib/dp-packet.c
@@ -294,6 +294,102 @@ dp_packet_prealloc_headroom(struct dp_packet
*b,
size_t size)
}
}
+#ifdef DPDK_NETDEV
+/* Write len data bytes in a mbuf at specified offset.
+ *
+ * 'mbuf', pointer to the destination mbuf where 'ofs' is, and the
mbuf where
+ * the data will first be written.
+ * 'ofs', the offset within the provided 'mbuf' where 'data' is to
be
written.
+ * 'len', the size of the to be written 'data'.
+ * 'data', pointer to the to be written bytes.
+ *
+ * XXX: This function is the counterpart of the
`rte_pktmbuf_read()`
function
+ * available with DPDK, in the rte_mbuf.h */
+void
+dp_packet_mbuf_write(struct rte_mbuf *mbuf, int16_t ofs, uint32_t
len,
+ const void *data)
+{
+ char *dst_addr;
+ uint16_t data_len;
+ int len_copy;
+ while (mbuf) {
+ if (len == 0) {
+ break;
+ }
+
+ dst_addr = rte_pktmbuf_mtod_offset(mbuf, char *, ofs);
+ data_len = MBUF_BUF_END(mbuf->buf_addr, mbuf->buf_len) -
dst_addr;
+
+ len_copy = MIN(len, data_len);
+ /* We don't know if 'data' is the result of a
rte_pktmbuf_read() call,
+ * in which case we may end up writing to the same region
of
memory we
+ * are reading from and overlapping. Hence the use of
memmove() here */
+ memmove(dst_addr, data, len_copy);
+
+ data = ((char *) data) + len_copy;
+ len -= len_copy;
+ ofs = 0;
+
+ mbuf = mbuf->next;
+ }
+}
+
+static void
+dp_packet_mbuf_shift_(struct rte_mbuf *dbuf, int16_t dst_ofs,
+ const struct rte_mbuf *sbuf, uint16_t
src_ofs,
int len)
+{
+ char rd[len];
+ const char *wd = rte_pktmbuf_read(sbuf, src_ofs, len, rd);
+
+ ovs_assert(wd);
+
