This commit is contained in:
Freya Murphy 2023-04-18 11:01:56 -04:00
parent 299380880a
commit 5eef60aa1a
6 changed files with 303 additions and 20 deletions

240
buffer.c Normal file
View file

@ -0,0 +1,240 @@
#include "buffer.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct PacketBuffer {
uint8_t* arr;
int capacity;
int index;
int size;
};
PacketBuffer* buffer_create(int capacity) {
PacketBuffer* buffer = malloc(sizeof(PacketBuffer));
buffer->arr = malloc(capacity);
buffer->capacity = capacity;
buffer->size = 0;
buffer->index = 0;
return buffer;
}
void buffer_free(PacketBuffer* buffer) {
free(buffer->arr);
free(buffer);
}
void buffer_seek(PacketBuffer* buffer, int index) {
buffer->index = index;
}
uint8_t buffer_read(PacketBuffer* buffer) {
if (buffer->index > buffer->size) {
return 0;
}
uint8_t data = buffer->arr[buffer->index];
buffer->index++;
return data;
}
uint16_t buffer_read_short(PacketBuffer* buffer) {
return
(uint16_t) buffer_read(buffer) << 8 |
(uint16_t) buffer_read(buffer);
}
uint32_t buffer_read_int(PacketBuffer* buffer) {
return
(uint32_t) buffer_read(buffer) << 24 |
(uint32_t) buffer_read(buffer) << 16 |
(uint32_t) buffer_read(buffer) << 8 |
(uint32_t) buffer_read(buffer);
}
uint8_t buffer_get(PacketBuffer* buffer, int index) {
if (index > buffer->size) {
return 0;
}
uint8_t data = buffer->arr[index];
return data;
}
uint8_t* buffer_get_range(PacketBuffer* buffer, int start, int len) {
uint8_t* arr = malloc(len);
for (int i = 0; i < len; i++) {
arr[i] = buffer_get(buffer, start + i);
}
return arr;
}
uint16_t buffer_get_size(PacketBuffer* buffer) {
return (uint16_t) buffer->size + 1;
}
static void write(uint8_t** buffer, uint8_t* size, uint8_t* capacity, uint8_t data) {
if (*size == *capacity) {
*capacity *= 2;
*buffer = realloc(*buffer, *capacity);
}
(*buffer)[*size] = data;
(*size)++;
}
void buffer_read_qname(PacketBuffer* buffer, uint8_t** out) {
int index = buffer->index;
int jumped = 0;
int max_jumps = 5;
int jumps_performed = 0;
uint8_t length = 0;
uint8_t capacity = 8;
*out = malloc(capacity);
write(out, &length, &capacity, 0);
while(1) {
if (jumps_performed > max_jumps) {
break;
}
uint8_t len = buffer_get(buffer, index);
if ((len & 0xC0) == 0xC0) {
if (jumped == 0) {
buffer_seek(buffer, index + 2);
}
uint16_t b2 = (uint16_t) buffer_get(buffer, index + 1);
uint16_t offset = ((((uint16_t) len) ^ 0xC0) << 8) | b2;
index = (int) offset;
jumped = 1;
jumps_performed++;
continue;
}
index++;
if (len == 0) {
break;
}
if (length > 1) {
write(out, &length, &capacity, '.');
}
uint8_t* range = buffer_get_range(buffer, index, len);
for (uint8_t i = 0; i < len; i++) {
write(out, &length, &capacity, range[i]);
}
free(range);
index += (int) len;
}
if (jumped == 0) {
buffer_seek(buffer, index);
}
(*out)[0] = length - 1;
}
void buffer_read_string(PacketBuffer* buffer, uint8_t** out) {
uint8_t len = buffer_read(buffer);
buffer_read_n(buffer, out, len);
}
void buffer_read_n(PacketBuffer* buffer, uint8_t** out, uint8_t len) {
*out = malloc(len + 1);
*out[0] = len;
memcpy(*out + 1, buffer->arr + buffer->index, len);
buffer->index += len;
}
void buffer_write(PacketBuffer* buffer, uint8_t data) {
if(buffer->index == buffer->capacity) {
buffer->capacity *= 2;
buffer->arr = realloc(buffer->arr, buffer->capacity);
}
if (buffer->size < buffer->index) {
buffer->size = buffer->index;
}
buffer->arr[buffer->index] = data;
buffer->index++;
}
void buffer_write_short(PacketBuffer* buffer, uint16_t data) {
buffer_write(buffer, (uint8_t)(data >> 8));
buffer_write(buffer, (uint8_t)(data & 0xFF));
}
void buffer_write_int(PacketBuffer* buffer, uint32_t data) {
buffer_write(buffer, (uint8_t)(data >> 24));
buffer_write(buffer, (uint8_t)(data >> 16));
buffer_write(buffer, (uint8_t)(data >> 8));
buffer_write(buffer, (uint8_t)(data & 0xFF));
}
void buffer_write_qname(PacketBuffer* buffer, uint8_t* in) {
uint8_t part = 0;
uint8_t len = in[0];
buffer_write(buffer, 0);
if (len == 0) {
return;
}
for(uint8_t i = 0; i < len; i ++) {
if (in[i+1] == '.') {
buffer_set(buffer, part, buffer->index - (int)part - 1);
buffer_write(buffer, 0);
part = 0;
} else {
buffer_write(buffer, in[i+1]);
part++;
}
}
buffer_set(buffer, part, buffer->index - (int)part - 1);
buffer_write(buffer, 0);
}
void buffer_write_string(PacketBuffer* buffer, uint8_t* in) {
buffer_write(buffer, in[0]);
buffer_write_n(buffer, in + 1, in[0]);
}
void buffer_write_n(PacketBuffer* buffer, uint8_t* in, int len) {
if (buffer->size + len >= buffer->capacity) {
buffer->capacity *= 2;
buffer->capacity += len;
buffer->arr = realloc(buffer->arr, buffer->capacity);
}
memcpy(buffer->arr + buffer->index, in, len);
buffer->size += len;
buffer->index += len;
}
void buffer_set(PacketBuffer* buffer, uint8_t data, int index) {
if (index > buffer->size) {
return;
}
buffer->arr[index] = data;
}
void buffer_set_uint16_t(PacketBuffer* buffer, uint16_t data, int index) {
buffer_set(buffer, (uint8_t)(data >> 8), index);
buffer_set(buffer, (uint8_t)(data & 0xFF), index + 1);
}
int buffer_get_index(PacketBuffer* buffer) {
return buffer->index;
}
void buffer_step(PacketBuffer* buffer, int len) {
buffer->index += len;
}
uint8_t* buffer_get_ptr(PacketBuffer* buffer) {
return buffer->arr;
}

View file

@ -1,7 +1,6 @@
#include "server/server.h"
#include <stdlib.h>
#include <sys/select.h>
#define DEFAULT_PORT 53

View file

@ -14,6 +14,7 @@ struct PacketBuffer {
PacketBuffer* buffer_create(int capacity) {
PacketBuffer* buffer = malloc(sizeof(PacketBuffer));
buffer->arr = malloc(capacity);
memset(buffer->arr, 0, capacity);
buffer->capacity = capacity;
buffer->size = 0;
buffer->index = 0;
@ -30,7 +31,7 @@ void buffer_seek(PacketBuffer* buffer, int index) {
}
uint8_t buffer_read(PacketBuffer* buffer) {
if (buffer->index > buffer->size) {
if (buffer->index >= buffer->size) {
return 0;
}
uint8_t data = buffer->arr[buffer->index];
@ -53,7 +54,7 @@ uint32_t buffer_read_int(PacketBuffer* buffer) {
}
uint8_t buffer_get(PacketBuffer* buffer, int index) {
if (index > buffer->size) {
if (index >= buffer->size) {
return 0;
}
uint8_t data = buffer->arr[index];
@ -73,8 +74,12 @@ uint16_t buffer_get_size(PacketBuffer* buffer) {
}
static void write(uint8_t** buffer, uint8_t* size, uint8_t* capacity, uint8_t data) {
if (*size == *capacity) {
*capacity *= 2;
if (*size >= *capacity) {
if (*capacity >= 128) {
*capacity = 255;
} else {
*capacity *= 2;
}
*buffer = realloc(*buffer, *capacity);
}
(*buffer)[*size] = data;
@ -144,7 +149,16 @@ void buffer_read_string(PacketBuffer* buffer, uint8_t** out) {
buffer_read_n(buffer, out, len);
}
static void buffer_expand(PacketBuffer* buffer, int capacity) {
if (buffer->capacity >= capacity) return;
buffer->arr = realloc(buffer->arr, capacity);
memset(buffer->arr + buffer->capacity, 0, capacity - buffer->capacity);
buffer->capacity = capacity;
}
void buffer_read_n(PacketBuffer* buffer, uint8_t** out, uint8_t len) {
buffer_expand(buffer, buffer->index + len + 1);
*out = malloc(len + 1);
*out[0] = len;
memcpy(*out + 1, buffer->arr + buffer->index, len);
@ -152,7 +166,7 @@ void buffer_read_n(PacketBuffer* buffer, uint8_t** out, uint8_t len) {
}
void buffer_write(PacketBuffer* buffer, uint8_t data) {
if(buffer->index == buffer->capacity) {
if(buffer->index >= buffer->capacity) {
buffer->capacity *= 2;
buffer->arr = realloc(buffer->arr, buffer->capacity);
}
@ -205,11 +219,7 @@ void buffer_write_string(PacketBuffer* buffer, uint8_t* in) {
}
void buffer_write_n(PacketBuffer* buffer, uint8_t* in, int len) {
if (buffer->size + len >= buffer->capacity) {
buffer->capacity *= 2;
buffer->capacity += len;
buffer->arr = realloc(buffer->arr, buffer->capacity);
}
buffer_expand(buffer, buffer->index + len + 1);
memcpy(buffer->arr + buffer->index, in, len);
buffer->size += len;
buffer->index += len;

View file

@ -140,17 +140,28 @@ static void read_txt_record(PacketBuffer* buffer, Record* record) {
TXTRecord data;
data.len = 0;
data.text = malloc(sizeof(uint8_t*) * 2);
uint8_t capacity = 2;
uint8_t total = record->len;
while (1) {
if (data.len >= capacity) {
capacity *= 2;
if (capacity >= 128) {
capacity = 255;
} else {
capacity *= 2;
}
data.text = realloc(data.text, sizeof(uint8_t*) * capacity);
}
buffer_read_string(buffer, &data.text[data.len]);
if(data.text[data.len][0] == 0) break;
if(data.text[data.len][0] == 0) {
free(data.text[data.len]);
break;
}
data.len++;
total -= data.text[data.len - 1][0] + 1;
if (total == 0) break;
}
record->data.txt = data;

View file

@ -1,3 +1,4 @@
#include <errno.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
@ -159,8 +160,30 @@ int32_t write_udp_socket(UdpSocket* socket, void* buffer, uint16_t len, SocketAd
);
}
static int get_socket_error(int fd) {
int err = 1;
socklen_t len = sizeof err;
if (-1 == getsockopt(fd, SOL_SOCKET, SO_ERROR, (char *)&err, &len))
return 0;
if (err)
errno = err;
return err;
}
static int close_socket(int fd) {
if (fd >= 0) {
get_socket_error(fd); // first clear any errors, which can cause close to fail
if (shutdown(fd, SHUT_RDWR) < 0) // secondly, terminate the 'reliable' delivery
if (errno != ENOTCONN && errno != EINVAL) // SGI causes EINVAL
perror("shutdown");
if (close(fd) < 0) // finally call close()
perror("close");
}
return 0;
}
int32_t close_udp_socket(UdpSocket* socket) {
return close(socket->sockfd);
return close_socket(socket->sockfd);
}
int32_t create_tcp_socket(AddrType type, TcpSocket* sock) {
@ -204,7 +227,7 @@ int32_t accept_tcp_socket(TcpSocket* socket, TcpStream* stream) {
}
int32_t close_tcp_socket(TcpSocket* socket) {
return close(socket->sockfd);
return close_socket(socket->sockfd);
}
int32_t connect_tcp_stream(SocketAddr* servaddr, TcpStream* stream) {
@ -222,7 +245,7 @@ int32_t connect_tcp_stream(SocketAddr* servaddr, TcpStream* stream) {
}
int32_t read_tcp_stream(TcpStream* stream, void* buffer, uint16_t len) {
return recv(stream->streamfd, buffer, len, 0);
return recv(stream->streamfd, buffer, len, MSG_WAITALL);
}
int32_t write_tcp_stream(TcpStream* stream, void* buffer, uint16_t len) {
@ -230,5 +253,5 @@ int32_t write_tcp_stream(TcpStream* stream, void* buffer, uint16_t len) {
}
int32_t close_tcp_stream(TcpStream* stream) {
return close(stream->streamfd);
return close_socket(stream->streamfd);
}

View file

@ -45,7 +45,7 @@ static bool lookup(
static bool search(Question* question, Packet* result, BindingType type, const RecordMap* map) {
IpAddr addr;
uint8_t ip[4] = {1, 1, 1, 1};
uint8_t ip[4] = {9,9,9,9};
create_ip_addr(ip, &addr);
uint16_t port = 53;