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feat: add helpers to extract id and sequence from replies

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lohhiiccc 2026-01-30 23:49:31 +01:00
parent 29904cbec6
commit 84490efc8e
4 changed files with 172 additions and 0 deletions
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4
includes/icmp.h
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@ -44,6 +44,10 @@ int icmp_send_echo(icmp_handle_t *h, struct in_addr dest, uint16_t id,
int icmp_process(icmp_handle_t *h, icmp_callback_t cb, void *userdata,
size_t max_packets);
/* ID/Sequence helpers */
int icmp_reply_id_seq(const icmp_reply_t *reply, uint16_t *id,
uint16_t *seq);
/* Error handling */
const char *icmp_strerror(const icmp_handle_t *h);
int icmp_should_retry(const icmp_handle_t *h);

2
sources.mk
View file

@ -28,6 +28,7 @@ SRCS += $(SRC_DIR)/recv/core/receive_packet.c
SRCS += $(SRC_DIR)/recv/core/parse_packet.c
SRCS += $(SRC_DIR)/recv/core/process_single_packet.c
SRCS += $(SRC_DIR)/recv/api/process.c
SRCS += $(SRC_DIR)/recv/api/extract_id_seq.c
TESTS_DIR = tests
TESTS += $(TESTS_DIR)/utils/test_checksum.c
@ -50,3 +51,4 @@ TESTS += $(TESTS_DIR)/recv/test_build_reply.c
TESTS += $(TESTS_DIR)/recv/test_receive_packet.c
TESTS += $(TESTS_DIR)/recv/test_parse_packet.c
TESTS += $(TESTS_DIR)/recv/test_process.c
TESTS += $(TESTS_DIR)/recv/test_extract_id_seq.c

27
src/recv/api/extract_id_seq.c Normal file
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@ -0,0 +1,27 @@
#include <netinet/in.h>
#include "icmp.h"
#include "icmp_types.h"
#include "internal/icmp_packet.h"
int
icmp_reply_id_seq(const icmp_reply_t *reply, uint16_t *id, uint16_t *seq)
{
const struct icmp_header *hdr;
if (NULL == reply)
return -1;
if (reply->type != ICMP_TYPE_ECHO_REPLY &&
reply->type != ICMP_TYPE_ECHO_REQUEST &&
reply->type != ICMP_TYPE_TIMESTAMP_REPLY &&
reply->type != ICMP_TYPE_TIMESTAMP_REQUEST)
return -1;
if (NULL == reply->ip_payload || reply->ip_payload_len < 8)
return -1;
hdr = reply->ip_payload;
if (NULL != id)
*id = ntohs(hdr->un.echo.id);
if (NULL != seq)
*seq = ntohs(hdr->un.echo.seq);
return 0;
}

139
tests/recv/test_extract_id_seq.c Normal file
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@ -0,0 +1,139 @@
#include <criterion/criterion.h>
#include <string.h>
#include "icmp.h"
static icmp_reply_t
make_echo_reply(uint8_t type, uint16_t id, uint16_t seq, uint8_t *buffer)
{
icmp_reply_t reply;
memset(&reply, 0, sizeof(reply));
memset(buffer, 0, 8);
reply.type = type;
reply.code = 0;
buffer[0] = type;
buffer[1] = 0;
buffer[2] = 0;
buffer[3] = 0;
buffer[4] = (id >> 8) & 0xFF;
buffer[5] = id & 0xFF;
buffer[6] = (seq >> 8) & 0xFF;
buffer[7] = seq & 0xFF;
reply.ip_payload = buffer;
reply.ip_payload_len = 8;
return reply;
}
Test(extract_echo, echo_reply_type_0)
{
uint8_t buffer[8];
icmp_reply_t reply = make_echo_reply(0, 0x1234, 0x5678, buffer);
uint16_t id;
uint16_t seq;
int ret;
ret = icmp_reply_id_seq(&reply, &id, &seq);
cr_assert_eq(ret, 0);
cr_assert_eq(id, 0x1234);
cr_assert_eq(seq, 0x5678);
}
Test(extract_echo, echo_request_type_8)
{
uint8_t buffer[8];
icmp_reply_t reply = make_echo_reply(8, 0xABCD, 0xEF01, buffer);
uint16_t id;
uint16_t seq;
int ret;
ret = icmp_reply_id_seq(&reply, &id, &seq);
cr_assert_eq(ret, 0);
cr_assert_eq(id, 0xABCD);
cr_assert_eq(seq, 0xEF01);
}
Test(extract_echo, non_echo_type_returns_error)
{
uint8_t buffer[8];
icmp_reply_t reply = make_echo_reply(3, 0x1234, 0x5678, buffer);
uint16_t id = 0xFFFF;
uint16_t seq = 0xFFFF;
int ret;
ret = icmp_reply_id_seq(&reply, &id, &seq);
cr_assert_eq(ret, -1);
cr_assert_eq(id, 0xFFFF, "id should be unchanged on error");
cr_assert_eq(seq, 0xFFFF, "seq should be unchanged on error");
}
Test(extract_echo, null_reply_returns_error)
{
uint16_t id;
uint16_t seq;
int ret;
ret = icmp_reply_id_seq(NULL, &id, &seq);
cr_assert_eq(ret, -1);
}
Test(extract_echo, null_id_allowed)
{
uint8_t buffer[8];
icmp_reply_t reply = make_echo_reply(0, 0x1234, 0x5678, buffer);
uint16_t seq;
int ret;
ret = icmp_reply_id_seq(&reply, NULL, &seq);
cr_assert_eq(ret, 0);
cr_assert_eq(seq, 0x5678);
}
Test(extract_echo, null_seq_allowed)
{
uint8_t buffer[8];
icmp_reply_t reply = make_echo_reply(0, 0x1234, 0x5678, buffer);
uint16_t id;
int ret;
ret = icmp_reply_id_seq(&reply, &id, NULL);
cr_assert_eq(ret, 0);
cr_assert_eq(id, 0x1234);
}
Test(extract_echo, both_null_allowed)
{
uint8_t buffer[8];
icmp_reply_t reply = make_echo_reply(0, 0x1234, 0x5678, buffer);
int ret;
ret = icmp_reply_id_seq(&reply, NULL, NULL);
cr_assert_eq(ret, 0);
}
Test(extract_echo, payload_too_short_returns_error)
{
uint8_t buffer[8];
icmp_reply_t reply = make_echo_reply(0, 0x1234, 0x5678, buffer);
uint16_t id;
uint16_t seq;
int ret;
reply.ip_payload_len = 7;
ret = icmp_reply_id_seq(&reply, &id, &seq);
cr_assert_eq(ret, -1);
}
Test(extract_echo, null_ip_payload_returns_error)
{
icmp_reply_t reply;
uint16_t id;
uint16_t seq;
int ret;
memset(&reply, 0, sizeof(reply));
reply.type = 0;
reply.ip_payload = NULL;
reply.ip_payload_len = 8;
ret = icmp_reply_id_seq(&reply, &id, &seq);
cr_assert_eq(ret, -1);
}