bugs

buffer.c

@@ -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;
+}

src/main.c

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

src/packet/buffer.c

@@ -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) {
+    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_expand(buffer, buffer->index + len + 1);
-        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;

src/packet/record.c

@@ -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) {
+            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;

src/server/addr.c

@@ -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);
 }

src/server/resolver.c

@@ -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;