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-rw-r--r--lib/librte_net/rte_ip.h71
1 files changed, 71 insertions, 0 deletions
diff --git a/lib/librte_net/rte_ip.h b/lib/librte_net/rte_ip.h
index 5b7554ab..4491b86e 100644
--- a/lib/librte_net/rte_ip.h
+++ b/lib/librte_net/rte_ip.h
@@ -230,6 +230,77 @@ rte_raw_cksum(const void *buf, size_t len)
}
/**
+ * Compute the raw (non complemented) checksum of a packet.
+ *
+ * @param m
+ * The pointer to the mbuf.
+ * @param off
+ * The offset in bytes to start the checksum.
+ * @param len
+ * The length in bytes of the data to ckecksum.
+ * @param cksum
+ * A pointer to the checksum, filled on success.
+ * @return
+ * 0 on success, -1 on error (bad length or offset).
+ */
+static inline int
+rte_raw_cksum_mbuf(const struct rte_mbuf *m, uint32_t off, uint32_t len,
+ uint16_t *cksum)
+{
+ const struct rte_mbuf *seg;
+ const char *buf;
+ uint32_t sum, tmp;
+ uint32_t seglen, done;
+
+ /* easy case: all data in the first segment */
+ if (off + len <= rte_pktmbuf_data_len(m)) {
+ *cksum = rte_raw_cksum(rte_pktmbuf_mtod_offset(m,
+ const char *, off), len);
+ return 0;
+ }
+
+ if (unlikely(off + len > rte_pktmbuf_pkt_len(m)))
+ return -1; /* invalid params, return a dummy value */
+
+ /* else browse the segment to find offset */
+ seglen = 0;
+ for (seg = m; seg != NULL; seg = seg->next) {
+ seglen = rte_pktmbuf_data_len(seg);
+ if (off < seglen)
+ break;
+ off -= seglen;
+ }
+ seglen -= off;
+ buf = rte_pktmbuf_mtod_offset(seg, const char *, off);
+ if (seglen >= len) {
+ /* all in one segment */
+ *cksum = rte_raw_cksum(buf, len);
+ return 0;
+ }
+
+ /* hard case: process checksum of several segments */
+ sum = 0;
+ done = 0;
+ for (;;) {
+ tmp = __rte_raw_cksum(buf, seglen, 0);
+ if (done & 1)
+ tmp = rte_bswap16(tmp);
+ sum += tmp;
+ done += seglen;
+ if (done == len)
+ break;
+ seg = seg->next;
+ buf = rte_pktmbuf_mtod(seg, const char *);
+ seglen = rte_pktmbuf_data_len(seg);
+ if (seglen > len - done)
+ seglen = len - done;
+ }
+
+ *cksum = __rte_raw_cksum_reduce(sum);
+ return 0;
+}
+
+/**
* Process the IPv4 checksum of an IPv4 header.
*
* The checksum field must be set to 0 by the caller.