X-Git-Url: https://gerrit.fd.io/r/gitweb?a=blobdiff_plain;f=drivers%2Fnet%2Ftap%2Ftap_bpf_api.c;fp=drivers%2Fnet%2Ftap%2Ftap_bpf_api.c;h=109a681ee2f70cf41edf7755def95c10382f482e;hb=ca33590b6af032bff57d9cc70455660466a654b2;hp=0000000000000000000000000000000000000000;hpb=169a9de21e263aa6599cdc2d87a45ae158d9f509;p=deb_dpdk.git

diff --git a/drivers/net/tap/tap_bpf_api.c b/drivers/net/tap/tap_bpf_api.c
new file mode 100644
index 00000000..109a681e
--- /dev/null
+++ b/drivers/net/tap/tap_bpf_api.c
@@ -0,0 +1,190 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright 2017 Mellanox Technologies, Ltd.
+ */
+
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/queue.h>
+
+#include <rte_malloc.h>
+#include <rte_eth_tap.h>
+#include <tap_flow.h>
+#include <tap_autoconf.h>
+#include <tap_tcmsgs.h>
+#include <tap_bpf.h>
+#include <tap_bpf_insns.h>
+
+/**
+ * Load BPF program (section cls_q) into the kernel and return a bpf fd
+ *
+ * @param queue_idx
+ *   Queue index matching packet cb
+ *
+ * @return
+ *   -1 if the BPF program couldn't be loaded. An fd (int) otherwise.
+ */
+int tap_flow_bpf_cls_q(__u32 queue_idx)
+{
+	cls_q_insns[1].imm = queue_idx;
+
+	return bpf_load(BPF_PROG_TYPE_SCHED_CLS,
+		(struct bpf_insn *)cls_q_insns,
+		RTE_DIM(cls_q_insns),
+		"Dual BSD/GPL");
+}
+
+/**
+ * Load BPF program (section l3_l4) into the kernel and return a bpf fd.
+ *
+ * @param[in] key_idx
+ *   RSS MAP key index
+ *
+ * @param[in] map_fd
+ *   BPF RSS map file descriptor
+ *
+ * @return
+ *   -1 if the BPF program couldn't be loaded. An fd (int) otherwise.
+ */
+int tap_flow_bpf_calc_l3_l4_hash(__u32 key_idx, int map_fd)
+{
+	l3_l4_hash_insns[4].imm = key_idx;
+	l3_l4_hash_insns[9].imm = map_fd;
+
+	return bpf_load(BPF_PROG_TYPE_SCHED_ACT,
+		(struct bpf_insn *)l3_l4_hash_insns,
+		RTE_DIM(l3_l4_hash_insns),
+		"Dual BSD/GPL");
+}
+
+/**
+ * Helper function to convert a pointer to unsigned 64 bits
+ *
+ * @param[in] ptr
+ *   pointer to address
+ *
+ * @return
+ *   64 bit unsigned long type of pointer address
+ */
+static inline __u64 ptr_to_u64(const void *ptr)
+{
+	return (__u64)(unsigned long)ptr;
+}
+
+/**
+ * Call BPF system call
+ *
+ * @param[in] cmd
+ *   BPF command for program loading, map creation, map entry update, etc
+ *
+ * @param[in] attr
+ *   System call attributes relevant to system call command
+ *
+ * @param[in] size
+ *   size of attr parameter
+ *
+ * @return
+ *   -1 if BPF system call failed, 0 otherwise
+ */
+static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
+			unsigned int size)
+{
+	return syscall(__NR_bpf, cmd, attr, size);
+}
+
+/**
+ * Load BPF instructions to kernel
+ *
+ * @param[in] type
+ *   BPF program type: classifieir or action
+ *
+ * @param[in] insns
+ *   Array of BPF instructions (equivalent to BPF instructions)
+ *
+ * @param[in] insns_cnt
+ *   Number of BPF instructions (size of array)
+ *
+ * @param[in] lincense
+ *   License string that must be acknowledged by the kernel
+ *
+ * @return
+ *   -1 if the BPF program couldn't be loaded, fd (file descriptor) otherwise
+ */
+static int bpf_load(enum bpf_prog_type type,
+		  const struct bpf_insn *insns,
+		  size_t insns_cnt,
+		  const char *license)
+{
+	union bpf_attr attr = {};
+
+	bzero(&attr, sizeof(attr));
+	attr.prog_type = type;
+	attr.insn_cnt = (__u32)insns_cnt;
+	attr.insns = ptr_to_u64(insns);
+	attr.license = ptr_to_u64(license);
+	attr.log_buf = ptr_to_u64(NULL);
+	attr.log_level = 0;
+	attr.kern_version = 0;
+
+	return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
+}
+
+/**
+ * Create BPF map for RSS rules
+ *
+ * @param[in] key_size
+ *   map RSS key size
+ *
+ * @param[in] value_size
+ *   Map RSS value size
+ *
+ * @param[in] max_entries
+ *   Map max number of RSS entries (limit on max RSS rules)
+ *
+ * @return
+ *   -1 if BPF map couldn't be created, map fd otherwise
+ */
+int tap_flow_bpf_rss_map_create(unsigned int key_size,
+		unsigned int value_size,
+		unsigned int max_entries)
+{
+	union bpf_attr attr = {};
+
+	bzero(&attr, sizeof(attr));
+	attr.map_type    = BPF_MAP_TYPE_HASH;
+	attr.key_size    = key_size;
+	attr.value_size  = value_size;
+	attr.max_entries = max_entries;
+
+	return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
+}
+
+/**
+ * Update RSS entry in BPF map
+ *
+ * @param[in] fd
+ *   RSS map fd
+ *
+ * @param[in] key
+ *   Pointer to RSS key whose entry is updated
+ *
+ * @param[in] value
+ *   Pointer to RSS new updated value
+ *
+ * @return
+ *   -1 if RSS entry failed to be updated, 0 otherwise
+ */
+int tap_flow_bpf_update_rss_elem(int fd, void *key, void *value)
+{
+	union bpf_attr attr = {};
+
+	bzero(&attr, sizeof(attr));
+
+	attr.map_type = BPF_MAP_TYPE_HASH;
+	attr.map_fd = fd;
+	attr.key = ptr_to_u64(key);
+	attr.value = ptr_to_u64(value);
+	attr.flags = BPF_ANY;
+
+	return sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
+}