* [PATCH gwproxy v1 1/2] add unit test
2025-07-28 5:14 [PATCH gwproxy v1 0/2] Introduce IPv6 support for dns parser program ReYuki
@ 2025-07-28 5:14 ` ReYuki
2025-07-28 5:14 ` [PATCH gwproxy v1 2/2] add support for AAAA record type ReYuki
` (2 subsequent siblings)
3 siblings, 0 replies; 6+ messages in thread
From: ReYuki @ 2025-07-28 5:14 UTC (permalink / raw)
To: GNU/Weeb Mailing List; +Cc: ReYuki
From: ReYuki <me@reyuki.site>
---
Makefile | 7 +++
gwdnsparserlib.c | 114 ++++++++++++++++++++++++++++++++++++++++++++++-
gwdnsparserlib.h | 21 ++++++---
3 files changed, 135 insertions(+), 7 deletions(-)
diff --git a/Makefile b/Makefile
index 9a03526..031695a 100644
--- a/Makefile
+++ b/Makefile
@@ -6,6 +6,7 @@ INOTIFYSRC := test_inotify.c linux.c
DNSCLIENTSRC := dnsclient.c general.c gwdnsparserlib.c
GWSOCKS5LIBSRC := gwsocks5lib.c linux.c general.c
GWDNSLIBSRC := gwdnslib.c linux.c
+PARSERLIBSRC := gwdnsparserlib.c
OBJS1 := $(patsubst %.c,$(BUILDDIR)/%.o,$(GWPROXYSRC))
OBJS2 := $(patsubst %.c,$(BUILDDIR)/%.o,$(CONVERTERSRC))
@@ -13,6 +14,7 @@ OBJS3 := $(patsubst %.c,$(BUILDDIR)/%.o,$(INOTIFYSRC))
OBJS5 := $(patsubst %.c,$(BUILDDIR)/%.o,$(DNSCLIENTSRC))
OBJS6 := $(patsubst %.c,$(BUILDDIR)/%.o,$(GWSOCKS5LIBSRC))
OBJS7 := $(patsubst %.c,$(BUILDDIR)/%.o,$(GWDNSLIBSRC))
+OBJS8 := $(patsubst %.c,$(BUILDDIR)/%.o,$(PARSERLIBSRC))
TARGET1 := $(BUILDDIR)/gwproxy
TARGET2 := $(BUILDDIR)/ip_converter
@@ -20,6 +22,7 @@ TARGET3 := $(BUILDDIR)/test_inotify
TARGET5 := $(BUILDDIR)/dnsclient
TARGET6 := $(BUILDDIR)/gwsocks5lib
TARGET7 := $(BUILDDIR)/gwdnslib
+TARGET8 := $(BUILDDIR)/gwdnsparserlib
CC := gcc
CFLAGS := -Wmaybe-uninitialized -Wall -Wextra -Os -g3
@@ -44,6 +47,8 @@ $(TARGET6): CFLAGS += -DRUNTEST -DENABLE_DUMP
$(TARGET6): $(OBJS6)
$(TARGET7): CFLAGS += -DRUNTEST
$(TARGET7): $(OBJS7)
+$(TARGET8): CFLAGS += -DRUNTEST
+$(TARGET8): $(OBJS8)
# test without log: make CFLAGS="-DENABLE_LOG=false" -B test_conventional
test_conventional: $(TARGET1)
@@ -55,6 +60,8 @@ test_dnsclient: $(TARGET5)
$< 1.1.1.1 53 google.com github.com facebook.com
test_gwsocks5lib: $(TARGET6)
$<
+test_gwdnsparserlib: $(TARGET8)
+ $<
.PHONY: clean
clean:
diff --git a/gwdnsparserlib.c b/gwdnsparserlib.c
index bf19c87..aa883d9 100644
--- a/gwdnsparserlib.c
+++ b/gwdnsparserlib.c
@@ -135,8 +135,6 @@ int serialize_answ(uint16_t txid, uint8_t *in, size_t in_len, gwdns_answ_data *o
memcpy(&rdlength, in, sizeof(rdlength));
rdlength = ntohs(rdlength);
item->rdlength = rdlength;
- /* TODO: for now it's always assume the size is 4 bytes long (IPv4) */
- assert(rdlength == 4);
in += 2;
item->rdata = malloc(rdlength);
@@ -194,3 +192,115 @@ ssize_t construct_question(gwdns_question_part *question)
return required_len;
}
+
+#ifdef RUNTEST
+
+void test_simulate_ipv4query(void)
+{
+ char buff[UDP_MSG_LIMIT];
+ gwdns_query_pkt *send_pkt;
+ uint8_t recv_pkt[] = {
+ /* Header (12 bytes) */
+ 0x00, 0x00, /* transaction ID - STUB! */
+ 0x81, 0x80, /* Flags: QR=1, AA=0, RD=1, RA=1, RCODE=0 */
+ 0x00, 0x01, /* QDCOUNT = 1 */
+ 0x00, 0x06, /* ANCOUNT = 6 */
+ 0x00, 0x00, /* NSCOUNT = 0 */
+ 0x00, 0x00, /* ARCOUNT = 0 */
+
+ /* Question Section */
+ /* Pointer label compression may be used in answers */
+ 0x06, 'g','o','o','g','l','e',
+ 0x03, 'c','o','m',
+ 0x00, /* Terminate name */
+ 0x00, 0x01, /* QTYPE = A */
+ 0x00, 0x01, /* QCLASS = IN */
+
+ /* Answer Section (6 records) */
+ /* Each Answer record: name pointer, type, class, ttl, rdlength, rdata */
+ /* First Answer */
+ 0xC0, 0x0C, /* Name: pointer to offset 0x0C (start of question name) */
+ 0x00, 0x01, /* TYPE = A */
+ 0x00, 0x01, /* CLASS = IN */
+ 0x00, 0x00, 0x08, 0x62, /* TTL = 0x00000862 = 2146 sec */
+ 0x00, 0x04, /* RDLENGTH = 4 */
+ 0x4A, 0x7D, 0x18, 0x71, /* RDATA = 74.125.24.113 */
+
+ /* Second Answer */
+ 0xC0, 0x0C,
+ 0x00, 0x01,
+ 0x00, 0x01,
+ 0x00, 0x00, 0x08, 0x62,
+ 0x00, 0x04,
+ 0x4A, 0x7D, 0x18, 0x65, /* 74.125.24.101 */
+
+ /* Third Answer */
+ 0xC0, 0x0C,
+ 0x00, 0x01,
+ 0x00, 0x01,
+ 0x00, 0x00, 0x08, 0x62,
+ 0x00, 0x04,
+ 0x4A, 0x7D, 0x18, 0x8B, /* 74.125.24.139 */
+
+ /* Fourth Answer */
+ 0xC0, 0x0C,
+ 0x00, 0x01,
+ 0x00, 0x01,
+ 0x00, 0x00, 0x08, 0x62,
+ 0x00, 0x04,
+ 0x4A, 0x7D, 0x18, 0x8A, /* 74.125.24.138 */
+
+ /* Fifth Answer */
+ 0xC0, 0x0C,
+ 0x00, 0x01,
+ 0x00, 0x01,
+ 0x00, 0x00, 0x08, 0x62,
+ 0x00, 0x04,
+ 0x4A, 0x7D, 0x18, 0x64, /* 74.125.24.100 */
+
+ /* Sixth Answer */
+ 0xC0, 0x0C,
+ 0x00, 0x01,
+ 0x00, 0x01,
+ 0x00, 0x00, 0x08, 0x62,
+ 0x00, 0x04,
+ 0x4A, 0x7D, 0x18, 0x66, /* 74.125.24.102 */
+ };
+ gwdns_answ_data d;
+ char first_label[] = "google";
+ char second_label[] = "com";
+
+ memset(&d, 0, sizeof(d));
+ gwdns_question_part q = {
+ .domain = "google.com",
+ .dst_buffer = (uint8_t *)buff,
+ .dst_len = sizeof(buff)
+ };
+ assert(construct_question(&q) > 0);
+
+ assert(buff[12] == 6);
+ assert(!memcmp(&buff[13], first_label, 6));
+
+ assert(buff[13 + 6] == 3);
+ assert(!memcmp(&buff[13 + 6 + 1], second_label, 3));
+
+ // fill the STUB
+ memcpy(recv_pkt, buff, 2);
+
+ send_pkt = (void *)buff;
+ assert(!serialize_answ(send_pkt->hdr.id, recv_pkt, sizeof(recv_pkt), &d));
+}
+
+void run_all_tests(void)
+{
+ test_simulate_ipv4query();
+ fprintf(stderr, "all tests passed!\n");
+}
+
+int main(void)
+{
+ run_all_tests();
+ return 0;
+}
+
+#endif
diff --git a/gwdnsparserlib.h b/gwdnsparserlib.h
index 3513442..d24e414 100644
--- a/gwdnsparserlib.h
+++ b/gwdnsparserlib.h
@@ -181,6 +181,17 @@ typedef struct {
size_t domain_nr;
} gwdns_resolv_hint;
+/*
+* Construct question packet
+*
+* @param prepared question
+* @return length of bytes written into dst_buffer on success, or a negative integer on failure.
+*
+* possible error are:
+* - ENAMETOOLONG domain name in question.name is too long.
+* - ENOBUFS length in question.dst_len is not sufficient.
+* - EINVAL malformed question.name
+*/
ssize_t construct_question(gwdns_question_part *question);
/*
@@ -192,10 +203,10 @@ ssize_t construct_question(gwdns_question_part *question);
* @return zero on success or a negative number on failure
*
* possible error are:
-* -EAGAIN in buffer is not sufficient, no bytes are processed, need more data.
-* -EINVAL the content of in buffer is not valid.
-* -ENOMEM failed to allocate dynamic memory.
-* -ENODATA the packet didn't contain any answers.
-* -EPROTO the DNS server can't understand your question
+* -EAGAIN in buffer is not sufficient, no bytes are processed, need more data.
+* -EINVAL the content of in buffer is not valid.
+* -ENOMEM failed to allocate dynamic memory.
+* -ENODATA the packet didn't contain any answers.
+* -EPROTO the DNS server can't understand your question
*/
int serialize_answ(uint16_t txid, uint8_t *in, size_t in_len, gwdns_answ_data *out);
\ No newline at end of file
--
ReYuki
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH gwproxy v1 2/2] add support for AAAA record type
2025-07-28 5:14 [PATCH gwproxy v1 0/2] Introduce IPv6 support for dns parser program ReYuki
2025-07-28 5:14 ` [PATCH gwproxy v1 1/2] add unit test ReYuki
@ 2025-07-28 5:14 ` ReYuki
2025-07-28 5:19 ` [PATCH gwproxy v1 0/2] Introduce IPv6 support for dns parser program reyuki
[not found] ` <CAADvAgoHZujWqiFWqjKXWHMtcJxvCBHZhdEp9Ysryy-8H6tkgg@mail.gmail.com>
3 siblings, 0 replies; 6+ messages in thread
From: ReYuki @ 2025-07-28 5:14 UTC (permalink / raw)
To: GNU/Weeb Mailing List; +Cc: ReYuki
From: ReYuki <me@reyuki.site>
https://datatracker.ietf.org/doc/html/rfc3596
2.1 AAAA record type
The AAAA resource record type is a record specific to the Internet
class that stores a single IPv6 address.
The IANA assigned value of the type is 28 (decimal).
the following is a sample from dig command (strace -x -s 512 dig A google.com):
// dns request query packet
// header section
\xfd\x11 // id
\x01\x20 // flags
\x00\x01 // qdcount
\x00\x00 // ancount
\x00\x00 // nscount
\x00\x01 // arcount
// question section
// name
\x06\x67\x6f\x6f\x67\x6c\x65
\x03\x63\x6f\x6d
\x00\x00 // type
\x1c\x00 // class
// additional resource section
\x01\x00\x00\x29\x04\xd0\x00\x00\x00\x00\x00\x0c\x00\x0a\x00\x08\x21\x06\x68\xe2\x80\xc2\xe8\xb8
// dns response answer packet
// header section
\xfd\x11 // id
\x81\x80 // flags
\x00\x01 // qdcount
\x00\x04 // ancount
\x00\x00 // nscount
\x00\x01 // arcount
// question section
\x06\x67\x6f\x6f\x67\x6c\x65
\x03\x63\x6f\x6d
\x00
\x00\x1c // type
\x00\x01 // class
// (1) answer section
\xc0\x0c // name
\x00\x1c // type
\x00\x01 // class
\x00\x00\x06\xd1 // ttl
\x00\x10 // rdlength
\x24\x04\x68\x00\x40\x03\x0c\x0f\x00\x00\x00\x00\x00\x00\x00\x8a // rdata
// (2) answer section
\xc0\x0c
\x00\x1c
\x00\x01
\x00\x00\x06\xd1
\x00\x10
\x24\x04\x68\x00\x40\x03\x0c\x0f\x00\x00\x00\x00\x00\x00\x00\x65
// (3) answer section
\xc0\x0c
\x00\x1c
\x00\x01
\x00\x00\x06\xd1
\x00\x10
\x24\x04\x68\x00\x40\x03\x0c\x0f\x00\x00\x00\x00\x00\x00\x00\x66
// (4) answer section
\xc0\x0c
\x00\x1c
\x00\x01
\x00\x00\x06\xd1
\x00\x10
\x24\x04\x68\x00\x40\x03\x0c\x0f\x00\x00\x00\x00\x00\x00\x00\x64
// additional resource section
\x00\x00\x29\x10\x00\x00\x00\x00\x00\x00\x00
---
dnsclient.c | 7 +++++--
gwdnsparserlib.c | 14 +++++++++++++-
gwdnsparserlib.h | 4 +++-
3 files changed, 21 insertions(+), 4 deletions(-)
diff --git a/dnsclient.c b/dnsclient.c
index 4d96b18..6f2e66c 100644
--- a/dnsclient.c
+++ b/dnsclient.c
@@ -83,6 +83,7 @@ static int send_query(struct io_uring *ring, int sockfd, char *domain, gwdns_que
q.domain = domain;
q.dst_buffer = buff->question;
q.dst_len = UDP_MSG_LIMIT;
+ q.type = TYPE_AAAA;
payload_len = construct_question(&q);
if (payload_len < 0)
return -1;
@@ -161,13 +162,15 @@ static int resolv_addr(char **domains, gwdns_resolv_hint *hint, gwdns_resolv_ctx
ctx->sqe_nr--;
printf("cqe->res=%d cqe->user_data=%llx\n", cqe->res, CLEAR_ID(cqe->user_data));
if (EXTRACT_ID(cqe->user_data) == ID) {
- char ipstr[INET_ADDRSTRLEN];
+ char ipstr[INET6_ADDRSTRLEN];
gwdns_answ_data d;
cqe->user_data = CLEAR_ID(cqe->user_data);
ret = serialize_answ((uint16_t)cqe->user_data, (uint8_t *)buff[idx].answr, cqe->res, &d);
for (size_t i = 0; i < d.hdr.ancount; i++) {
- inet_ntop(AF_INET, d.rr_answ[i]->rdata, ipstr, sizeof(ipstr));
+ gwdns_serialized_answ *p = d.rr_answ[i];
+ int sa_family = p->rr_type == TYPE_AAAA ? AF_INET6 : AF_INET;
+ inet_ntop(sa_family, p->rdata, ipstr, sizeof(ipstr));
printf("%s\n", ipstr);
}
diff --git a/gwdnsparserlib.c b/gwdnsparserlib.c
index aa883d9..022ccc2 100644
--- a/gwdnsparserlib.c
+++ b/gwdnsparserlib.c
@@ -1,3 +1,5 @@
+#define _DEFAULT_SOURCE
+#include <endian.h>
#include "gwdnsparserlib.h"
static ssize_t construct_qname(uint8_t *dst, size_t dst_len, const char *qname)
@@ -126,14 +128,21 @@ int serialize_answ(uint16_t txid, uint8_t *in, size_t in_len, gwdns_answ_data *o
in += 2; // NAME
memcpy(&item->rr_type, in, 2);
+ item->rr_type = ntohs(item->rr_type);
in += 2; // TYPE
memcpy(&item->rr_class, in, 2);
+ item->rr_class = ntohs(item->rr_class);
in += 2; // CLASS
memcpy(&item->ttl, in, 4);
+ item->ttl = be32toh(item->ttl);
in += 4; // TTL
memcpy(&rdlength, in, sizeof(rdlength));
rdlength = ntohs(rdlength);
+ if (item->rr_type == TYPE_AAAA && rdlength != sizeof(struct in6_addr))
+ return -EINVAL;
+ if (item->rr_type == TYPE_A && rdlength != sizeof(struct in_addr))
+ return -EINVAL;
item->rdlength = rdlength;
in += 2;
@@ -153,6 +162,9 @@ ssize_t construct_question(gwdns_question_part *question)
size_t required_len;
ssize_t bw;
+ if (question->type != TYPE_AAAA && question->type != TYPE_A)
+ return -EINVAL;
+
hdr = &pkt.hdr;
/*
* the memset implicitly set opcode to query
@@ -177,7 +189,7 @@ ssize_t construct_question(gwdns_question_part *question)
return bw;
pkt.body[bw++] = 0x0;
- qtype = htons(TYPE_A);
+ qtype = htons(question->type);
qclass = htons(CLASS_IN);
memcpy(&pkt.body[bw], &qtype, 2);
bw += 2;
diff --git a/gwdnsparserlib.h b/gwdnsparserlib.h
index d24e414..c5948d0 100644
--- a/gwdnsparserlib.h
+++ b/gwdnsparserlib.h
@@ -91,6 +91,7 @@ typedef enum {
TYPE_MINFO = 14, // mailbox or mail list information
TYPE_MX = 15, // mail exchange
TYPE_TXT = 16, // text strings
+ TYPE_AAAA = 28, // text strings
QTYPE_AXFR = 252, // A request for a transfer of an entire zone
QTYPE_MAILB = 253, // A request for mailbox-related records (MB, MG or MR)
QTYPE_ALL = 255 // A request for all records
@@ -119,6 +120,7 @@ typedef struct {
typedef struct {
uint8_t *dst_buffer;
+ uint16_t type;
size_t dst_len;
char *domain;
} gwdns_question_part;
@@ -190,7 +192,7 @@ typedef struct {
* possible error are:
* - ENAMETOOLONG domain name in question.name is too long.
* - ENOBUFS length in question.dst_len is not sufficient.
-* - EINVAL malformed question.name
+* - EINVAL malformed or unsupported value in question data
*/
ssize_t construct_question(gwdns_question_part *question);
--
ReYuki
^ permalink raw reply related [flat|nested] 6+ messages in thread