diff options
Diffstat (limited to 'v5/apf_interpreter.c')
| -rw-r--r-- | v5/apf_interpreter.c | 71 |
1 files changed, 60 insertions, 11 deletions
diff --git a/v5/apf_interpreter.c b/v5/apf_interpreter.c index 3cef719..9c6175d 100644 --- a/v5/apf_interpreter.c +++ b/v5/apf_interpreter.c @@ -17,7 +17,7 @@ #include "apf_interpreter.h" // TODO: Remove the dependency of the standard library and make the interpreter self-contained. -#include <string.h> // For memcmp +#include <string.h>// For memcmp #include "apf.h" @@ -43,11 +43,17 @@ extern void APF_TRACE_HOOK(uint32_t pc, const uint32_t* regs, const uint8_t* pro // superfluous ">= 0" with unsigned expressions generates compile warnings. #define ENFORCE_UNSIGNED(c) ((c)==(uint32_t)(c)) -int apf_run(uint8_t* program, uint32_t program_len, uint32_t ram_len, - const uint8_t* packet, uint32_t packet_len, - uint32_t filter_age) { +uint32_t apf_version() { + return 20231122; +} + +int apf_run(uint8_t* const program, const uint32_t program_len, + const uint32_t ram_len, const uint8_t* const packet, + const uint32_t packet_len, const uint32_t filter_age_16384ths) { // Is offset within program bounds? #define IN_PROGRAM_BOUNDS(p) (ENFORCE_UNSIGNED(p) && (p) < program_len) +// Is offset within ram bounds? +#define IN_RAM_BOUNDS(p) (ENFORCE_UNSIGNED(p) && (p) < ram_len) // Is offset within packet bounds? #define IN_PACKET_BOUNDS(p) (ENFORCE_UNSIGNED(p) && (p) < packet_len) // Is access to offset |p| length |size| within data bounds? @@ -58,6 +64,8 @@ int apf_run(uint8_t* program, uint32_t program_len, uint32_t ram_len, (p) + (size) >= (p)) // catch wraparounds // Accept packet if not within program bounds #define ASSERT_IN_PROGRAM_BOUNDS(p) ASSERT_RETURN(IN_PROGRAM_BOUNDS(p)) +// Accept packet if not within ram bounds +#define ASSERT_IN_RAM_BOUNDS(p) ASSERT_RETURN(IN_RAM_BOUNDS(p)) // Accept packet if not within packet bounds #define ASSERT_IN_PACKET_BOUNDS(p) ASSERT_RETURN(IN_PACKET_BOUNDS(p)) // Accept packet if not within data bounds @@ -74,7 +82,7 @@ int apf_run(uint8_t* program, uint32_t program_len, uint32_t ram_len, memory[MEMORY_OFFSET_PROGRAM_SIZE] = program_len; memory[MEMORY_OFFSET_DATA_SIZE] = ram_len; memory[MEMORY_OFFSET_PACKET_SIZE] = packet_len; - memory[MEMORY_OFFSET_FILTER_AGE] = filter_age; + memory[MEMORY_OFFSET_FILTER_AGE] = filter_age_16384ths >> 14; ASSERT_IN_PACKET_BOUNDS(APF_FRAME_HEADER_SIZE); // Only populate if IP version is IPv4. if ((packet[APF_FRAME_HEADER_SIZE] & 0xf0) == 0x40) { @@ -92,6 +100,18 @@ int apf_run(uint8_t* program, uint32_t program_len, uint32_t ram_len, uint8_t* allocated_buffer = NULL; // The length of the output buffer uint32_t allocate_buffer_len = 0; +// Is access to offset |p| length |size| within output buffer bounds? +#define IN_OUTPUT_BOUNDS(p, size) (ENFORCE_UNSIGNED(p) && \ + ENFORCE_UNSIGNED(size) && \ + (p) + (size) <= allocate_buffer_len && \ + (p) + (size) >= (p)) +// Accept packet if not write within allocated output buffer +#define ASSERT_IN_OUTPUT_BOUNDS(p, size) ASSERT_RETURN(IN_OUTPUT_BOUNDS(p, size)) + +// Decode the imm length. +#define DECODE_IMM(value, length) \ + for (uint32_t i = 0; i < (length) && pc < program_len; i++) \ + value = (value << 8) | program[pc++] do { APF_TRACE_HOOK(pc, registers, program, program_len, packet, packet_len, memory, ram_len); @@ -113,9 +133,7 @@ int apf_run(uint8_t* program, uint32_t program_len, uint32_t ram_len, if (len_field != 0) { const uint32_t imm_len = 1 << (len_field - 1); ASSERT_FORWARD_IN_PROGRAM(pc + imm_len - 1); - uint32_t i; - for (i = 0; i < imm_len; i++) - imm = (imm << 8) | program[pc++]; + DECODE_IMM(imm, imm_len); // Sign extend imm into signed_imm. signed_imm = imm << ((4 - imm_len) * 8); signed_imm >>= (4 - imm_len) * 8; @@ -178,9 +196,7 @@ int apf_run(uint8_t* program, uint32_t program_len, uint32_t ram_len, } else if (len_field != 0) { uint32_t cmp_imm_len = 1 << (len_field - 1); ASSERT_FORWARD_IN_PROGRAM(pc + cmp_imm_len - 1); - uint32_t i; - for (i = 0; i < cmp_imm_len; i++) - cmp_imm = (cmp_imm << 8) | program[pc++]; + DECODE_IMM(cmp_imm, cmp_imm_len); } switch (opcode) { case JEQ_OPCODE: @@ -307,6 +323,14 @@ int apf_run(uint8_t* program, uint32_t program_len, uint32_t ram_len, 0 /* dscp */); allocated_buffer = NULL; break; + case DATA_EXT_OPCODE: { + ASSERT_FORWARD_IN_PROGRAM(pc + 1); + uint32_t skip_len = 0; + DECODE_IMM(skip_len, 2); + ASSERT_FORWARD_IN_PROGRAM(pc + skip_len - 1); + pc += skip_len; + break; + } // Unknown extended opcode default: // Bail out @@ -346,6 +370,31 @@ int apf_run(uint8_t* program, uint32_t program_len, uint32_t ram_len, } break; } + case MEMCOPY_OPCODE: { + ASSERT_RETURN(allocated_buffer != NULL); + ASSERT_RETURN(len_field > 0); + uint32_t src_offs = imm; + uint32_t copy_len = 0; + DECODE_IMM(copy_len, 1); + uint32_t dst_offs = memory[MEMORY_OFFSET_OUTPUT_BUFFER_OFFSET]; + ASSERT_IN_OUTPUT_BOUNDS(dst_offs, copy_len); + // reg_num == 0 copy from packet, reg_num == 1 copy from data. + if (reg_num == 0) { + ASSERT_IN_PACKET_BOUNDS(src_offs); + const uint32_t last_packet_offs = src_offs + copy_len - 1; + ASSERT_RETURN(last_packet_offs >= src_offs); + ASSERT_IN_PACKET_BOUNDS(last_packet_offs); + memmove(allocated_buffer + dst_offs, packet + src_offs, + copy_len); + } else { + ASSERT_IN_RAM_BOUNDS(src_offs + copy_len - 1); + memmove(allocated_buffer + dst_offs, program + src_offs, + copy_len); + } + dst_offs += copy_len; + memory[MEMORY_OFFSET_OUTPUT_BUFFER_OFFSET] = dst_offs; + break; + } // Unknown opcode default: // Bail out |