clj-ebpf.dsl.jump — org.clojars.pgdad/clj-ebpf 0.1.1

Jump and control flow operations for BPF programs.

Provides:

• Conditional jumps (jeq, jne, jgt, jge, etc.)
• Unconditional jumps (ja)
• Function calls (call)
• Program exit (exit)

call clj

(call helper-id)

Call a BPF helper function.

r0 = bpf_helper(r1, r2, r3, r4, r5)

Arguments:

• helper-id: BPF helper function ID (e.g., 1 for map_lookup_elem)

exit-insn clj

(exit-insn)

Exit the BPF program.

return r0

The value in r0 is returned to the caller.

ja clj

(ja offset)

Unconditional jump.

goto +offset

Arguments:

• offset: Jump offset (in instructions)

ja-label clj

(ja-label label-name)

Unconditional jump to label.

jeq clj

(jeq dst src-or-imm offset)

Jump if equal.

if (dst == src/imm) goto +offset

jeq-label clj

(jeq-label dst src-or-imm label-name)

Jump if equal to label.

if (dst == src/imm) goto label

jge clj

(jge dst src-or-imm offset)

Jump if greater than or equal (unsigned).

if (dst >= src/imm) goto +offset

jgt clj

(jgt dst src-or-imm offset)

Jump if greater than (unsigned).

if (dst > src/imm) goto +offset

jle clj

(jle dst src-or-imm offset)

Jump if less than or equal (unsigned).

if (dst <= src/imm) goto +offset

jlt clj

(jlt dst src-or-imm offset)

Jump if less than (unsigned).

if (dst < src/imm) goto +offset

jmp-imm clj

(jmp-imm op dst imm offset)

Conditional jump with immediate comparison.

if (dst OP imm) goto +offset

Arguments:

• op: Jump operation (:jeq, :jne, :jgt, etc.)
• dst: Register to compare
• imm: Immediate value to compare against
• offset: Jump offset (in instructions, not bytes)

jmp-ops clj

Map of jump operation keywords to BPF opcodes

jmp-reg clj

(jmp-reg op dst src offset)

Conditional jump with register comparison.

if (dst OP src) goto +offset

Arguments:

• op: Jump operation (:jeq, :jne, :jgt, etc.)
• dst: Register to compare
• src: Register to compare against
• offset: Jump offset (in instructions)

jmp32-imm clj

(jmp32-imm op dst imm offset)

32-bit conditional jump with immediate comparison.

if ((u32)dst OP imm) goto +offset

jmp32-reg clj

(jmp32-reg op dst src offset)

32-bit conditional jump with register comparison.

if ((u32)dst OP (u32)src) goto +offset

jne clj

(jne dst src-or-imm offset)

Jump if not equal.

if (dst != src/imm) goto +offset

jne-label clj

(jne-label dst src-or-imm label-name)

Jump if not equal to label.

jset clj

(jset dst src-or-imm offset)

Jump if bitwise AND is non-zero.

if (dst & src/imm) goto +offset

jsge clj

(jsge dst src-or-imm offset)

Jump if greater than or equal (signed).

if ((s64)dst >= (s64)src/imm) goto +offset

jsgt clj

(jsgt dst src-or-imm offset)

Jump if greater than (signed).

if ((s64)dst > (s64)src/imm) goto +offset

jsle clj

(jsle dst src-or-imm offset)

Jump if less than or equal (signed).

if ((s64)dst <= (s64)src/imm) goto +offset

jslt clj

(jslt dst src-or-imm offset)

Jump if less than (signed).

if ((s64)dst < (s64)src/imm) goto +offset

label clj

(label name)

Create a label marker for the assembler.

Labels are resolved during assembly to compute jump offsets.

label-ref clj

(label-ref name)

Create a reference to a label.

Used as the offset argument in jump instructions.

label-ref? clj

(label-ref? v)

Check if a value is a label reference.

label? clj

(label? insn)

Check if an instruction is a label.

tail-call clj

(tail-call)

Generate a tail call to another BPF program.

This is essentially: bpf_tail_call(ctx, prog_array, index) Helper ID 12 = bpf_tail_call