diff options
Diffstat (limited to 'drivers/net/tap/tap_bpf_api.c')
| -rw-r--r-- | drivers/net/tap/tap_bpf_api.c | 190 |
1 files changed, 190 insertions, 0 deletions
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)); +} |