bpf: support packet data load instructions

[dpdk.git] / lib / librte_bpf / bpf_exec.c

diff --git a/lib/librte_bpf/bpf_exec.c b/lib/librte_bpf/bpf_exec.c
index 1bb2266..b921112 100644 (file)
--- a/lib/librte_bpf/bpf_exec.c
+++ b/lib/librte_bpf/bpf_exec.c
@@ -74,6 +74,26 @@
                (uintptr_t)((reg)[(ins)->dst_reg] + (ins)->off), \
                reg[ins->src_reg]))
 
+/* BPF_LD | BPF_ABS/BPF_IND */
+
+#define        NOP(x)  (x)
+
+#define BPF_LD_ABS(bpf, reg, ins, type, op) do { \
+       const type *p = bpf_ld_mbuf(bpf, reg, ins, (ins)->imm, sizeof(type)); \
+       if (p == NULL)  \
+               return 0; \
+       reg[EBPF_REG_0] = op(p[0]); \
+} while (0)
+
+#define BPF_LD_IND(bpf, reg, ins, type, op) do { \
+       uint32_t ofs = reg[ins->src_reg] + (ins)->imm; \
+       const type *p = bpf_ld_mbuf(bpf, reg, ins, ofs, sizeof(type)); \
+       if (p == NULL)  \
+               return 0; \
+       reg[EBPF_REG_0] = op(p[0]); \
+} while (0)
+
+
 static inline void
 bpf_alu_be(uint64_t reg[EBPF_REG_NUM], const struct ebpf_insn *ins)
 {
@@ -112,6 +132,23 @@ bpf_alu_le(uint64_t reg[EBPF_REG_NUM], const struct ebpf_insn *ins)
        }
 }
 
+static inline const void *
+bpf_ld_mbuf(const struct rte_bpf *bpf, uint64_t reg[EBPF_REG_NUM],
+       const struct ebpf_insn *ins, uint32_t off, uint32_t len)
+{
+       const struct rte_mbuf *mb;
+       const void *p;
+
+       mb = (const struct rte_mbuf *)(uintptr_t)reg[EBPF_REG_6];
+       p = rte_pktmbuf_read(mb, off, len, reg + EBPF_REG_0);
+       if (p == NULL)
+               RTE_BPF_LOG(DEBUG, "%s(bpf=%p, mbuf=%p, ofs=%u, len=%u): "
+                       "load beyond packet boundary at pc: %#zx;\n",
+                       __func__, bpf, mb, off, len,
+                       (uintptr_t)(ins) - (uintptr_t)(bpf)->prm.ins);
+       return p;
+}
+
 static inline uint64_t
 bpf_exec(const struct rte_bpf *bpf, uint64_t reg[EBPF_REG_NUM])
 {
@@ -296,6 +333,26 @@ bpf_exec(const struct rte_bpf *bpf, uint64_t reg[EBPF_REG_NUM])
                                (uint64_t)(uint32_t)ins[1].imm << 32;
                        ins++;
                        break;
+               /* load absolute instructions */
+               case (BPF_LD | BPF_ABS | BPF_B):
+                       BPF_LD_ABS(bpf, reg, ins, uint8_t, NOP);
+                       break;
+               case (BPF_LD | BPF_ABS | BPF_H):
+                       BPF_LD_ABS(bpf, reg, ins, uint16_t, rte_be_to_cpu_16);
+                       break;
+               case (BPF_LD | BPF_ABS | BPF_W):
+                       BPF_LD_ABS(bpf, reg, ins, uint32_t, rte_be_to_cpu_32);
+                       break;
+               /* load indirect instructions */
+               case (BPF_LD | BPF_IND | BPF_B):
+                       BPF_LD_IND(bpf, reg, ins, uint8_t, NOP);
+                       break;
+               case (BPF_LD | BPF_IND | BPF_H):
+                       BPF_LD_IND(bpf, reg, ins, uint16_t, rte_be_to_cpu_16);
+                       break;
+               case (BPF_LD | BPF_IND | BPF_W):
+                       BPF_LD_IND(bpf, reg, ins, uint32_t, rte_be_to_cpu_32);
+                       break;
                /* store instructions */
                case (BPF_STX | BPF_MEM | BPF_B):
                        BPF_ST_REG(reg, ins, uint8_t);