Imported Upstream version 16.11

[deb_dpdk.git] / lib / librte_net / rte_ip.h

diff --git a/lib/librte_net/rte_ip.h b/lib/librte_net/rte_ip.h
index 5b7554a..4491b86 100644 (file)
--- a/lib/librte_net/rte_ip.h
+++ b/lib/librte_net/rte_ip.h
@@ -229,6 +229,77 @@ rte_raw_cksum(const void *buf, size_t len)
        return __rte_raw_cksum_reduce(sum);
 }
 
+/**
+ * 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.
  *