SnailMan/C-IPC
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Client can now actually send messages via command

Browse Source 
Client can now specify the recipient of a message and type it. Messages for offline users are saved, unaccesible for now.
This commit is contained in:
Piotr Kozak
2026-01-05 18:04:59 +01:00
parent 4a089ed368
commit 6d495468c8
5 changed files with 216 additions and 54 deletions
Download Patch File Download Diff File Expand all files Collapse all files
Makefile
+2 -2
View File
@@ -5,11 +5,11 @@ all: client server
client:
mkdir -p build
$(CC) $(CFLAGS) -o build/client client.c
$(CC) $(CFLAGS) -o build/client client.c util/util.c
server:
mkdir -p build
$(CC) $(CFLAGS) -o build/server server.c
$(CC) $(CFLAGS) -o build/server server.c util/util.c
clean:
rm -f client server
client.c
+79 -34
View File
@@ -29,6 +29,70 @@ static void cleanup_queue(int qid) {
}
}
static void input_loop(int server_queue_id, const char *client_id) {
while (1) {
// Minimum length plus extra space fore command name and seperators
// I'd prefer some more space than required to not have to worry about cut
// offs
char buffer[COMMAND_LENGTH + MESSAGE_LENGTH + 64];
if (fgets(buffer, sizeof(buffer), stdin) == NULL) {
break;
}
buffer[strcspn(buffer, "\n")] = '\0';
if (strncmp(buffer, "/msg ", 5) == 0) {
// In a /msg command we expect {u|g}:<nickname up to 14 chars> <message up
// to 256 chars>
char *space_ptr = strchr(buffer + 5, ' ');
if (space_ptr == NULL) {
printf("Invalid /msg format. Use /msg u:<nickname> <message>\n");
continue;
}
char target[COMMAND_LENGTH];
size_t target_len = space_ptr - (buffer + 5);
if (target_len >= COMMAND_LENGTH) {
printf("Target nickname too long\n");
continue;
}
strncpy(target, buffer + 5, target_len);
target[target_len] = '\0';
char *message = space_ptr + 1;
if (strlen(message) == 0) {
printf("Message cannot be empty\n");
continue;
}
// Check the format of the command string
if (target[1] != ':') {
printf("Invalid target format. Use u:<nickname> or g:<groupname>\n");
continue;
}
if (target[0] != 'u' && target[0] != 'g') {
printf("Invalid target type. Use 'u' for user or 'g' for group\n");
continue;
}
msgbuf_t msg = {.mtype = Message, .sender = ""};
strncpy(msg.sender, client_id, COMMAND_LENGTH - 1);
snprintf(msg.command, COMMAND_LENGTH, "%s", target);
strncpy(msg.message, message, MESSAGE_LENGTH - 1);
if (send(server_queue_id, &msg) == -1) {
perror("msgsnd(/msg) failed");
}
} else if (strncmp(buffer, "/list", 5) == 0) {
// handle list
} else if (strncmp(buffer, "/mute ", 6) == 0) {
// handle mute
} else if (strcmp(buffer, "/quit") == 0) {
// exit
} else {
printf("Unknown command\n");
}
}
}
int main(int argc, char *argv[]) {
if (argc < 2) {
fprintf(stderr, "Usage: %s <client_id>\n", argv[0]);
@@ -91,33 +155,27 @@ int main(int argc, char *argv[]) {
return 0;
}
/* Send a test message to the server */
msgbuf_t test = {.mtype = Message, .sender = ""};
strncpy(test.sender, client_id, COMMAND_LENGTH - 1);
snprintf(test.message, MESSAGE_LENGTH, "Hello from %s", client_id);
if (msgsnd(server_queue_id, &test, sizeof(test) - sizeof(long), 0) == -1) {
printf("DEBUG: test.mtype = %u\n", test.mtype);
perror("failed while sending a test message");
cleanup_queue(client_queue_id);
return 1;
if (fork() == 0) {
input_loop(server_queue_id, client_id);
return 0;
}
printf("Sent test message to server: \"%s\"\n", test.message);
// /* Send a test message to the server */
// msgbuf_t test = {.mtype = Message, .command = "u:test2", .sender = ""};
// strncpy(test.sender, client_id, COMMAND_LENGTH - 1);
// snprintf(test.message, MESSAGE_LENGTH, "Hello from %s", client_id);
/* Now wait for server forwarded message(s) and a signal ack.
We'll wait until we've seen both a Message and a Signal ack or timeout.
*/
int seen_message = 0;
int seen_ack = 0;
const int MAX_ITER = 10;
// if (msgsnd(server_queue_id, &test, sizeof(test) - sizeof(long), 0) == -1) {
// printf("DEBUG: test.mtype = %u\n", test.mtype);
// perror("failed while sending a test message");
// cleanup_queue(client_queue_id);
// return 1;
// }
// for (int i = 0; i < MAX_ITER && !(seen_message && seen_ack); ++i) {
while (1) {
msgbuf_t incoming;
ssize_t got = msgrcv(client_queue_id, &incoming,
sizeof(incoming) - sizeof(long), 0, 0);
perror("Got a message damn");
if (got == -1) {
perror("msgrcv(incoming) failed");
@@ -130,14 +188,10 @@ int main(int argc, char *argv[]) {
switch (incoming.mtype) {
case Message:
printf("Received Message: \"%s\"\n", incoming.message);
seen_message = 1;
printf("%s: %s\n", incoming.sender, incoming.message);
break;
case Signal:
printf("Received Signal: code=%d\n", incoming.stype);
if (incoming.stype == ACK_ACCEPTED || incoming.stype == ACK_DELIVERED) {
seen_ack = 1;
}
break;
default:
printf("Received unknown mtype=%ld stype=%d\n", (long)incoming.mtype,
@@ -146,15 +200,6 @@ int main(int argc, char *argv[]) {
}
}
if (!seen_message) {
fprintf(stderr, "Did not receive forwarded message from server\n");
}
if (!seen_ack) {
fprintf(stderr, "Did not receive ack from server\n");
}
/* Logout/cleanup: remove our queue */
cleanup_queue(client_queue_id);
printf("Client exiting\n");
return 0;
}
server.c
+108 -18
View File
@@ -13,10 +13,18 @@
#include <unistd.h>
#include "commands.h"
#include "util/util.h"
#define send(queue_id, msgbuf_ptr) \
msgsnd(queue_id, msgbuf_ptr, sizeof(*(msgbuf_ptr)) - sizeof(long), 0)
typedef struct {
char sender[COMMAND_LENGTH];
char command[COMMAND_LENGTH];
char message[MESSAGE_LENGTH];
int message_id;
} saved_message_t;
typedef struct {
char *id;
bool logged_in;
@@ -24,6 +32,9 @@ typedef struct {
char nickname[16];
int queue_id;
long last_seen;
// Things for keeping track of the saved messages
saved_message_t saved_messages[20];
int saved_message_count;
} Client;
typedef struct {
@@ -36,7 +47,7 @@ static void handle_hearbeat_timeouts(Client *clients, int client_count,
int semaphore_id) {
struct sembuf sem_op = {
.sem_num = 0,
.sem_op = 1,
.sem_op = -1,
.sem_flg = 0,
};
while (1) {
@@ -53,7 +64,7 @@ static void handle_hearbeat_timeouts(Client *clients, int client_count,
clients[i].queue_id = -1;
}
}
sem_op.sem_op = -1;
sem_op.sem_op = 1;
semop(semaphore_id, &sem_op, 1);
sleep(HEARTBEAT_TIMEOUT);
}
@@ -117,7 +128,7 @@ int main(int argc, char **argv) {
case Login:
printf("Received login request for id: %s\n", msgbuf.sender);
Client *client = NULL;
for (int i = 0; i < 1; i++) {
for (int i = 0; i < client_count; i++) {
if (strncmp(clients[i].id, msgbuf.sender, COMMAND_LENGTH) == 0) {
client = &clients[i];
break;
@@ -157,6 +168,7 @@ int main(int argc, char **argv) {
.mtype = Login,
.stype = ACK_ACCEPTED,
};
printf("User accepted: %s\n", msgbuf.sender);
send(msg_queue_id, &response);
break;
@@ -186,24 +198,102 @@ int main(int argc, char **argv) {
continue;
}
printf("Forwarding message: %s\n", msgbuf.message);
// Now we have to decode if we are to forward this message to a user or a
// group first character of command indicates that - u or g
char target_type = msgbuf.command[0];
char target_id[COMMAND_LENGTH];
// Skip the first char and a separtor (:)
strncpy(target_id, msgbuf.command + 2, COMMAND_LENGTH - 2);
// TODO: Find the actual recipients, for now broadcast
msgbuf_t forward_msg = {
.mtype = Message,
};
strncpy(forward_msg.message, msgbuf.message, MESSAGE_LENGTH);
// Yes, the client sending the message also receives it
for (int i = 0; i < client_count; i++) {
if (clients[i].logged_in) {
send(clients[i].queue_id, &forward_msg);
if (target_type == 'u') {
Client *target_client = NULL;
for (int i = 0; i < client_count; i++) {
if (strncmp(clients[i].id, target_id, COMMAND_LENGTH) == 0) {
target_client = &clients[i];
break;
}
}
if (target_client == NULL) {
// Target client not found or not logged in
printf("Target client %s not found or not logged in\n", target_id);
msgbuf_t response = {
.mtype = Message,
.stype = ERR_USER_NOT_FOUND,
};
send(client->queue_id, &response);
continue;
}
// Check if the target is online or not, if they are not, store the
// message
if (!target_client->logged_in) {
if (target_client->saved_message_count >= 20) {
// Discard the oldest one and shift the rest to make room
for (int i = 1; i < target_client->saved_message_count; i++) {
target_client->saved_messages[i - 1] =
target_client->saved_messages[i];
}
saved_message_t *saved_msg =
&target_client
->saved_messages[target_client->saved_message_count - 1];
strncpy(saved_msg->sender, client->nickname, COMMAND_LENGTH);
strncpy(saved_msg->message, msgbuf.message, MESSAGE_LENGTH);
saved_msg->message_id = rand(); // Random id for the message
printf("Message saved for offline client %s\n", target_id);
// Send out an ack for the sender
msgbuf_t response = {
.mtype = Message,
.stype = ACK_ACCEPTED,
};
send(client->queue_id, &response);
continue;
}
saved_message_t *saved_msg =
&target_client
->saved_messages[target_client->saved_message_count++];
strncpy(saved_msg->sender, client->nickname, COMMAND_LENGTH);
strncpy(saved_msg->message, msgbuf.message, MESSAGE_LENGTH);
saved_msg->message_id = rand(); // Random id for the message
msgbuf_t response = {
.mtype = Message,
.stype = ACK_ACCEPTED,
};
send(client->queue_id, &response);
printf("Message saved for offline client %s\n", target_id);
continue;
}
printf("Forwarding message to user %s: %s\n", target_client->id,
msgbuf.message);
msgbuf_t forward_msg = {
.mtype = Message,
.sender = "",
};
strncpy(forward_msg.sender, client->nickname, COMMAND_LENGTH);
strncpy(forward_msg.message, msgbuf.message, MESSAGE_LENGTH);
send(target_client->queue_id, &forward_msg);
forward_msg.stype = ACK_ACCEPTED;
forward_msg.mtype = Signal;
send(client->queue_id, &forward_msg);
printf("Forwarding message: %s\n", msgbuf.message);
} else if (target_type == 'g') {
// Forward to a group
} else {
printf("Invalid target type: %c\n", target_type);
msgbuf_t response = {
.mtype = Message,
.stype = ERR_INVALID_FORMAT,
};
send(client->queue_id, &response);
continue;
}
forward_msg.stype = ACK_ACCEPTED;
forward_msg.mtype = Signal;
send(client->queue_id, &forward_msg);
// TODO: Accepted and Delivered ack
break;
case Logout:
util/util.c
+26
View File
@@ -0,0 +1,26 @@
#include <stdlib.h>
#include <string.h>
static char alphs[] = {'-', '_', '0', '1', '2', '3', '4', '5', '6', '7', '8',
'9', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u',
'v', 'w', 'x', 'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F',
'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q',
'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', '\0'};
// Generate an id used for messages. Could be less than 16 chars, but thats what
// fits into the `command` field of `msgbuf_t`.
void get_id(char *id_buf) {
int alph_size = strlen(alphs) - 1;
for (int i = 0; i < 16; i++) {
int random_num;
do {
random_num = rand();
} while (random_num >= (RAND_MAX - RAND_MAX % alph_size));
random_num %= alph_size;
id_buf[i] = alphs[random_num];
}
id_buf[15] = '\0';
}
util/util.h
+1
View File
@@ -0,0 +1 @@
void get_id(char *id_buf);