add code to send invalid messages

1 files changed, 51 insertions, 15 deletions

diff --git a/snowcast_server_concurrent.c b/snowcast_server_concurrent.c
index 2c74cab..4fa6d40 100644
--- a/snowcast_server_concurrent.c
+++ b/snowcast_server_concurrent.c
@@ -67,7 +67,8 @@ void *update_user_station(int sockfd, int stationNum);
 void *print_user_data(int sockfd);
 void destroy_user(int sockfd);
 
-void send_announce_message(int fd, int station_num);
+void send_announce_reply(int fd, int station_num);
+void send_invalid_command_reply(int fd, size_t message_size, char* message);
 
 
 // void *load_file(void* arg);
@@ -164,7 +165,7 @@ int main(int argc, char *argv[])
             pthread_create(&print_info_thread, NULL, print_info_routine, print_fd);
             // note - this file descriptor is closed in the thread
         }
-        else if (strncmp("u\n", input, LINE_MAX) == 0)
+        else if (!strcmp(command, "u"))
         {
             // print all user data
             for (int i = 0; i < max_active_users; i++)
@@ -415,7 +416,7 @@ void *synchronization_thread(void *arg) {
                     // update the station of each user
                     if (user_data[i].stationNum == i)
                     {
-                        send_announce_message(user_data[i].sockfd, i);
+                        send_announce_reply(user_data[i].sockfd, i);
                     }
                 }
             }
@@ -552,7 +553,7 @@ void *select_thread(void *arg) {
                         // we got some data from a client
                         if (command.commandType == 0) {
                             // hello message with udpPort
-                            printf("udpPort (from Hello) for new connection is %d.\n", ntohs(command.number));
+                            // printf("udpPort (from Hello) for new connection is %d.\n", ntohs(command.number));
                             // update udp port of user
                             update_user_udpPort(i, ntohs(command.number));
 
@@ -565,22 +566,37 @@ void *select_thread(void *arg) {
                                 perror("send");
                         }
                         else if (command.commandType == 1) {
+                            // check if user has a udpPort
+                            if (user_data[sockfd_to_user[i]].udpPort == -1) {
+                                // send back in invalid command
+                                char * message = "Must send Hello message first";
+                                send_invalid_command_reply(i, strlen(message), message);
+                                // drop connection upon invalid command
+                                close(i);
+                                FD_CLR(i, &master);
+                                destroy_user(i);
+                            }
+
                             int station_num = ntohs(command.number);
-                            printf("setting station to %d\n", ntohs(command.number));
+                            if (station_num >= num_stations || station_num < 0) {
+                                // send back in invalid command
+                                char * message = "Station number out of range";
+                                send_invalid_command_reply(i, strlen(message), message);
+                                // drop connection upon invalid command
+                                close(i);
+                                FD_CLR(i, &master);
+                                destroy_user(i);
+                            }
+
+                            // printf("setting station to %d\n", ntohs(command.number));
                             // update station of user
                             update_user_station(i, ntohs(command.number));
-
-                            send_announce_message(i, station_num);
+                            send_announce_reply(i, station_num);
                         }
                         else {
                             // send back in invalid command
-                            struct InvalidCommand invalid;
-                            invalid.replyType = 4;
-                            invalid.replyStringSize = 21;
-                            // make a string with the command.commmandType type in it
-                            invalid.replyString = "Invalid command type";
-                            if ((send(i, &invalid, sizeof(struct InvalidCommand), 0)) == -1)
-                                perror("send");
+                            char * message = "Invalid command";
+                            send_invalid_command_reply(i, strlen(message), message);
                             
                             // drop connection upon invalid command
                             close(i);
@@ -671,7 +687,7 @@ void *get_in_addr(struct sockaddr *sa)
     return &(((struct sockaddr_in6*)sa)->sin6_addr);
 }
 
-void send_announce_message(int fd, int station_num) {
+void send_announce_reply(int fd, int station_num) {
     char* file_path = station_data[station_num].filePath;
     int len_file_path = strlen(file_path);
 
@@ -692,6 +708,26 @@ void send_announce_message(int fd, int station_num) {
     free(send_buffer);
 }
 
+void send_invalid_command_reply(int fd, size_t message_size, char* message) {
+    char *send_buffer = malloc(message_size+2);
+
+    // type and payload size
+    send_buffer[0] = 4;
+    send_buffer[1] = message_size;
+
+    memcpy(send_buffer + 2, message, message_size);
+
+    // printf("buffer: %s\n", send_buffer);
+
+    int bytessent;
+    if ((bytessent = send(fd, send_buffer, message_size + 2, 0)) == -1)
+        perror("send");
+    // print the number of bytes sent
+    // printf("sent %d bytes\n", bytessent);
+
+    free(send_buffer);
+}
+
 
 // Parses a buffer into tokens, from cs33 :)
 int parse(char buffer[LINE_MAX], char *tokens[LINE_MAX / 2]) {