[v2] lib/net: add MPLS insert and strip functionality
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Commit Message
From: Tanzeel Ahmed <tanxeel1.ahmed@gmail.com>
This patch is new version of [PATCH] lib/net: added push MPLS header API.
I have also added the MPLS strip functionality in the same patch to
address the question asked in last patch.
> You should explain why you add this function.
None of the foundational NICs currently supports MPLS insertion and
stripping, this functionality can help users who rely on MPLS in their
network application.
> I'm not sure it should be inline
I did for perfomance in high-traffic application.
Signed-off-by: Tanzeel Ahmed <tanxeel1.ahmed@gmail.com>
---
v2:
* marked experimental
* coding style fixed
* changed rte_memcpy to memcpy
* mpls header marked as const in parameter
* added MPLS stripping functionality
---
.mailmap | 1 +
lib/net/rte_mpls.h | 97 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 98 insertions(+)
@@ -1312,6 +1312,7 @@ Takeshi Yoshimura <tyos@jp.ibm.com> <t.yoshimura8869@gmail.com>
Takuya Asada <syuu@cloudius-systems.com>
Tal Avraham <talavr@annapurnalabs.com>
Tal Shnaiderman <talshn@nvidia.com> <talshn@mellanox.com>
+Tanzeel Ahmed <tanxeel1.ahmed@gmail.com>
Tao Y Yang <tao.y.yang@intel.com>
Tao Zhu <taox.zhu@intel.com>
Taripin Samuel <samuel.taripin@intel.com>
@@ -13,6 +13,8 @@
#include <stdint.h>
#include <rte_byteorder.h>
+#include <rte_ether.h>
+#include <rte_mbuf.h>
#ifdef __cplusplus
extern "C" {
@@ -36,6 +38,101 @@ struct rte_mpls_hdr {
uint8_t ttl; /**< Time to live. */
} __rte_packed;
+#define RTE_MPLS_HLEN 4 /**< Length of MPLS header. */
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
+ * Insert MPLS header into the packet.
+ * If it's first MPLS header to be inserted in the packet,
+ * - Updates the ether type.
+ * - Sets the MPLS bottom-of-stack bit to 1.
+ *
+ * @param m
+ * The pointer to the mbuf.
+ * @param mp
+ * The pointer to the MPLS header.
+ * @return
+ * 0 on success, -1 on error
+ */
+__rte_experimental
+static int
+rte_mpls_push_over_l2(struct rte_mbuf **m, const struct rte_mpls_hdr *mp)
+{
+ struct rte_ether_hdr *oh, *nh;
+ struct rte_mpls_hdr *mph;
+
+ /* Can't insert header if mbuf is shared */
+ if (!RTE_MBUF_DIRECT(*m) || rte_mbuf_refcnt_read(*m) > 1)
+ return -EINVAL;
+
+ /* Can't insert header if ethernet frame doesn't exist */
+ if (rte_pktmbuf_data_len(*m) < RTE_ETHER_HDR_LEN)
+ return -EINVAL;
+
+ oh = rte_pktmbuf_mtod(*m, struct rte_ether_hdr *);
+ nh = (struct rte_ether_hdr *)(void *)
+ rte_pktmbuf_prepend(*m, sizeof(struct rte_mpls_hdr));
+ if (nh == NULL)
+ return -ENOSPC;
+
+ memmove(nh, oh, RTE_ETHER_HDR_LEN);
+
+ /* Copy the MPLS header after ethernet frame */
+ mph = rte_pktmbuf_mtod_offset(*m, struct rte_mpls_hdr*,
+ sizeof(struct rte_ether_hdr));
+ memcpy(mph, mp, RTE_MPLS_HLEN);
+
+ mph->tag_msb = rte_cpu_to_be_16(mp->tag_msb);
+
+ /* If first MPLS header, update ether type and bottom-of-stack bit */
+ if (nh->ether_type != rte_cpu_to_be_16(RTE_ETHER_TYPE_MPLS)) {
+ nh->ether_type = rte_cpu_to_be_16(RTE_ETHER_TYPE_MPLS);
+ mph->bs = 1;
+ } else {
+ mph->bs = 0;
+ }
+
+ return 0;
+}
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
+ * Strips MPLS from the packet. Doesn't update the ether type
+ *
+ * @param m
+ * The pointer to the mbuf.
+ * @return
+ * 0 on success, -1 on error
+ */
+__rte_experimental
+static inline int
+rte_mpls_strip_over_l2(struct rte_mbuf *m)
+{
+ struct rte_ether_hdr *eh = rte_pktmbuf_mtod(m, struct rte_ether_hdr *);
+ struct rte_mpls_hdr *mph;
+ bool mpls_exist = true;
+
+ if (eh->ether_type != rte_cpu_to_be_16(RTE_ETHER_TYPE_MPLS))
+ return -1;
+
+ /* Stripping all MPLS header */
+ while (mpls_exist) {
+ mph = rte_pktmbuf_mtod_offset(m, struct rte_mpls_hdr*,
+ sizeof(struct rte_ether_hdr));
+ if (mph->bs & 1)
+ mpls_exist = false;
+ memmove(rte_pktmbuf_adj(m, sizeof(struct rte_mpls_hdr)),
+ eh, sizeof(struct rte_ether_hdr));
+ eh = rte_pktmbuf_mtod(m, struct rte_ether_hdr *);
+ }
+
+ return 0;
+}
+
#ifdef __cplusplus
}
#endif