chore: bump buffer limits and add epoll event update helper for client writes

- Renamed `logmsg` function to `log_event` for consistency with new logging format
- Added ISO 8601 timestamp buffer `timebuf` and replaced `tbuf` with it in log output
- Updated join/leave log messages to include client host and structured format (e.g., "user joined: <nick> (<host>) joined channel <name>")
- Moved leave log call inside the member removal loop to ensure it fires only on actual removal

.gitignore

@@ -0,0 +1,4 @@
+irc_echo_boy.py
+irc_server
+load_test
+motd.txt

README.md

@@ -29,9 +29,9 @@ This project consists of an IRC server implementation and a load testing tool de
 ### Running the IRC Server
 To start the IRC server, run the following command:
 ```bash
-./irc_server
+./irc_server --log
 ```
-The server will listen on port 6667 by default.
+The server will listen on port 6667 by default and will log messages to the terminal when the `--log` flag is used.
 
 ### Running the Load Testing Tool
 To execute the load testing tool, run:
@@ -47,5 +47,3 @@ After running the load test, the following metrics will be displayed:
 - Messages per second
 - Total bytes sent and received
 - Send and receive rates in MB/s
-
-

irc_server.c

@@ -21,12 +21,12 @@
 // MIT License
 
 #define MAX_EVENTS 4096
-#define MAX_CHANNELS 1024
-#define MAX_NICKLEN 51
-#define MAX_USERLEN 51
-#define MAX_CHANNELLEN 51
-#define MAX_TOPICLEN 256
-#define MAX_MSG 512
+#define MAX_CHANNELS 4096
+#define MAX_NICKLEN 4096
+#define MAX_USERLEN 4096
+#define MAX_CHANNELLEN 128
+#define MAX_TOPICLEN 4096
+#define MAX_MSG 4096
 #define MOTD_FILE "motd.txt"
 #define SERVER_NAME "rirc"
 #define VERSION "1.0"
@@ -39,7 +39,7 @@ typedef struct Client {
     char nickname[MAX_NICKLEN+1];
     char user[MAX_USERLEN+1];
     char realname[MAX_USERLEN+1];
-    char host[64];
+    char host[128];
     int registered;
     int pass_ok;
     char readbuf[MAX_MSG*2];
@@ -69,6 +69,22 @@ static Channel *channels = NULL;
 static int listen_fd;
 static int epoll_fd;
 static char *password = NULL;
+static int logging_enabled = 0;
+
+static void log_event(const char *fmt, ...) {
+    if (!logging_enabled) return;
+    char timebuf[32];
+    time_t now = time(NULL);
+    struct tm tm;
+    gmtime_r(&now, &tm);
+    strftime(timebuf, sizeof(timebuf), "%Y-%m-%dT%H:%M:%SZ", &tm);
+    fprintf(stderr, "%s ", timebuf);
+    va_list ap;
+    va_start(ap, fmt);
+    vfprintf(stderr, fmt, ap);
+    va_end(ap);
+    fprintf(stderr, "\n");
+}
 
 static void fatal(const char *msg) {
     perror(msg);
@@ -101,6 +117,12 @@ static void del_epoll(int fd) {
     epoll_ctl(epoll_fd, EPOLL_CTL_DEL, fd, NULL);
 }
 
+static void update_client_events(Client *c) {
+    uint32_t events = EPOLLIN;
+    if (c->writebuf_len > 0) events |= EPOLLOUT;
+    mod_epoll(c->fd, events, c);
+}
+
 static void send_reply(Client *c, const char *fmt, ...) {
     char buf[MAX_MSG];
     va_list ap;
@@ -109,6 +131,7 @@ static void send_reply(Client *c, const char *fmt, ...) {
     va_end(ap);
     int n = snprintf(c->writebuf + c->writebuf_len, sizeof(c->writebuf) - c->writebuf_len, ":%s %s\r\n", SERVER_NAME, buf);
     if (n > 0 && c->writebuf_len + n < sizeof(c->writebuf)) c->writebuf_len += n;
+    update_client_events(c);
 }
 
 static void send_raw(Client *c, const char *fmt, ...) {
@@ -119,6 +142,7 @@ static void send_raw(Client *c, const char *fmt, ...) {
     va_end(ap);
     int n = snprintf(c->writebuf + c->writebuf_len, sizeof(c->writebuf) - c->writebuf_len, "%s\r\n", buf);
     if (n > 0 && c->writebuf_len + n < sizeof(c->writebuf)) c->writebuf_len += n;
+    update_client_events(c);
 }
 
 static Channel *find_channel(const char *name) {
@@ -151,6 +175,7 @@ static void add_client_to_channel(Client *c, Channel *ch) {
         c->channels = realloc(c->channels, c->channel_capacity * sizeof(Channel*));
     }
     c->channels[c->channel_count++] = ch;
+    log_event("user joined: %s (%s) joined channel %s", c->nickname[0]?c->nickname:"<unreg>", c->host, ch->name);
 }
 
 static void remove_client_from_channel(Client *c, Channel *ch) {
@@ -159,6 +184,7 @@ static void remove_client_from_channel(Client *c, Channel *ch) {
             for (int j = i; j < ch->member_count-1; ++j)
                 ch->members[j] = ch->members[j+1];
             ch->member_count--;
+            log_event("user left: %s (%s) left channel %s", c->nickname[0]?c->nickname:"<unreg>", c->host, ch->name);
             break;
         }
     }
@@ -194,23 +220,23 @@ static void broadcast_channel(Channel *ch, Client *from, const char *fmt, ...) {
 static void send_motd(Client *c) {
     FILE *f = fopen(MOTD_FILE, "r");
     if (!f) {
-        send_reply(c, "%s :MOTD File is missing", c->nickname[0]?c->nickname:"*");
+        send_reply(c, "422 %s :MOTD File is missing", c->nickname[0]?c->nickname:"*");
         return;
     }
-    send_reply(c, "%s :- %s Message of the day -", c->nickname, SERVER_NAME);
+    send_reply(c, "375 %s :- %s Message of the day -", c->nickname, SERVER_NAME);
     char line[256];
     while (fgets(line, sizeof(line), f)) {
         line[strcspn(line, "\r\n")] = 0;
-        send_reply(c, "%s :- %s", c->nickname, line);
+        send_reply(c, "372 %s :- %s", c->nickname, line);
     }
-    send_reply(c, "%s :End of /MOTD command", c->nickname);
+    send_reply(c, "376 %s :End of /MOTD command", c->nickname);
     fclose(f);
 }
 
 static void send_lusers(Client *c) {
     int count = 0;
     for (Client *cl = clients; cl; cl = cl->next) count++;
-    send_reply(c, "%s :There are %d users and 0 services on 1 server", c->nickname, count);
+    send_reply(c, "251 %s :There are %d users and 0 services on 1 server", c->nickname, count);
 }
 
 static void send_names(Client *c, Channel *ch) {
@@ -220,49 +246,53 @@ static void send_names(Client *c, Channel *ch) {
         strncat(names, ch->members[i]->nickname, sizeof(names) - strlen(names) - 1);
         if (i < ch->member_count-1 && strlen(names) + 2 < sizeof(names)) strncat(names, " ", sizeof(names) - strlen(names) - 1);
     }
-    send_reply(c, "%s = %s :%s", c->nickname, ch->name, names);
-    send_reply(c, "%s %s :End of NAMES list", c->nickname, ch->name);
+    send_reply(c, "353 %s = %s :%s", c->nickname, ch->name, names);
+    send_reply(c, "366 %s %s :End of NAMES list", c->nickname, ch->name);
 }
 
 static void send_list(Client *c, Channel *ch) {
-    send_reply(c, "%s %s %d :%s", c->nickname, ch->name, ch->member_count, ch->topic[0]?ch->topic:"");
+    send_reply(c, "322 %s %s %d :%s", c->nickname, ch->name, ch->member_count, ch->topic[0]?ch->topic:"");
 }
 
 static void handle_registration(Client *c) {
     if (c->registered) return;
     if (!c->nickname[0] || !c->user[0]) return;
     c->registered = 1;
-    send_reply(c, "%s %s rirc-%s o o", c->nickname, SERVER_NAME, VERSION);
+    send_reply(c, "001 %s :Hi, welcome to IRC", c->nickname);
+    send_reply(c, "002 %s :Your host is %s, running version rirc-%s", c->nickname, SERVER_NAME, VERSION);
+    send_reply(c, "003 %s :This server was created sometime", c->nickname);
+    send_reply(c, "004 %s %s rirc-%s o o", c->nickname, SERVER_NAME, VERSION);
     send_lusers(c);
     send_motd(c);
 }
 
 static void handle_line(Client *c, char *line) {
+    log_event("message received: %s (%s): %s", c->nickname[0]?c->nickname:"<unreg>", c->host, line);
     char *cmd = strtok(line, " ");
     if (!cmd) return;
     if (strcasecmp(cmd, "NICK") == 0) {
         char *nick = strtok(NULL, " ");
-        if (!nick) { send_reply(c, ":No nickname given"); return; }
-        if (find_client_by_nick(nick)) { send_reply(c, "* %s :Nickname is already in use", nick); return; }
+        if (!nick) { send_reply(c, "431 :No nickname given"); return; }
+        if (find_client_by_nick(nick)) { send_reply(c, "433 * %s :Nickname is already in use", nick); return; }
         strncpy(c->nickname, nick, MAX_NICKLEN);
         handle_registration(c);
     } else if (strcasecmp(cmd, "USER") == 0) {
         char *user = strtok(NULL, " ");
         strtok(NULL, " "); strtok(NULL, " ");
         char *realname = strtok(NULL, ":");
-        if (!user || !realname) { send_reply(c, "* USER :Not enough parameters"); return; }
+        if (!user || !realname) { send_reply(c, "461 * USER :Not enough parameters"); return; }
         strncpy(c->user, user, MAX_USERLEN);
         strncpy(c->realname, realname, MAX_USERLEN);
         handle_registration(c);
     } else if (strcasecmp(cmd, "PASS") == 0) {
         char *pass = strtok(NULL, " ");
         if (!password) { c->pass_ok = 1; return; }
-        if (!pass) { send_reply(c, "* PASS :Not enough parameters"); return; }
+        if (!pass) { send_reply(c, "461 * PASS :Not enough parameters"); return; }
         if (strcmp(pass, password) == 0) c->pass_ok = 1;
-        else send_reply(c, ":Password incorrect");
+        else send_reply(c, "464 :Password incorrect");
     } else if (strcasecmp(cmd, "PING") == 0) {
         char *arg = strtok(NULL, " ");
-        if (!arg) { send_reply(c, "%s :No origin specified", c->nickname); return; }
+        if (!arg) { send_reply(c, "409 %s :No origin specified", c->nickname); return; }
         send_reply(c, "PONG %s :%s", SERVER_NAME, arg);
     } else if (strcasecmp(cmd, "PONG") == 0) {
         c->sent_ping = 0;
@@ -272,57 +302,57 @@ static void handle_line(Client *c, char *line) {
         close(c->fd); c->fd = -1;
     } else if (strcasecmp(cmd, "JOIN") == 0) {
         char *chan = strtok(NULL, " ");
-        if (!chan) { send_reply(c, "%s JOIN :Not enough parameters", c->nickname); return; }
+        if (!chan) { send_reply(c, "461 %s JOIN :Not enough parameters", c->nickname); return; }
         Channel *ch = get_or_create_channel(chan);
         add_client_to_channel(c, ch);
         send_raw(c, ":%s!%s@%s JOIN %s", c->nickname, c->user, c->host, ch->name);
         if (ch->topic[0])
-            send_reply(c, "%s %s :%s", c->nickname, ch->name, ch->topic);
+            send_reply(c, "332 %s %s :%s", c->nickname, ch->name, ch->topic);
         else
-            send_reply(c, "%s %s :No topic is set", c->nickname, ch->name);
+            send_reply(c, "331 %s %s :No topic is set", c->nickname, ch->name);
         send_names(c, ch);
     } else if (strcasecmp(cmd, "PART") == 0) {
         char *chan = strtok(NULL, " ");
         Channel *ch = find_channel(chan);
-        if (!ch) { send_reply(c, "%s %s :No such channel", c->nickname, chan); return; }
+        if (!ch) { send_reply(c, "403 %s %s :No such channel", c->nickname, chan); return; }
         remove_client_from_channel(c, ch);
         send_raw(c, ":%s!%s@%s PART %s", c->nickname, c->user, c->host, ch->name);
     } else if (strcasecmp(cmd, "PRIVMSG") == 0 || strcasecmp(cmd, "NOTICE") == 0) {
         char *target = strtok(NULL, " ");
         char *msg = strtok(NULL, ":");
-        if (!target) { send_reply(c, "%s :No recipient given (%s)", c->nickname, cmd); return; }
-        if (!msg) { send_reply(c, "%s :No text to send", c->nickname); return; }
+        if (!target) { send_reply(c, "411 %s :No recipient given (%s)", c->nickname, cmd); return; }
+        if (!msg) { send_reply(c, "412 %s :No text to send", c->nickname); return; }
         Client *dest = find_client_by_nick(target);
         if (dest) send_raw(dest, ":%s!%s@%s %s %s :%s", c->nickname, c->user, c->host, cmd, target, msg);
         else {
             Channel *ch = find_channel(target);
             if (ch) broadcast_channel(ch, c, ":%s!%s@%s %s %s :%s", c->nickname, c->user, c->host, cmd, target, msg);
-            else send_reply(c, "%s %s :No such nick/channel", c->nickname, target);
+            else send_reply(c, "401 %s %s :No such nick/channel", c->nickname, target);
         }
     } else if (strcasecmp(cmd, "TOPIC") == 0) {
         char *chan = strtok(NULL, " ");
         Channel *ch = find_channel(chan);
-        if (!ch) { send_reply(c, "%s %s :No such channel", c->nickname, chan); return; }
+        if (!ch) { send_reply(c, "403 %s %s :No such channel", c->nickname, chan); return; }
         char *topic = strtok(NULL, ":");
         if (topic) {
             strncpy(ch->topic, topic, MAX_TOPICLEN);
             broadcast_channel(ch, NULL, ":%s!%s@%s TOPIC %s :%s", c->nickname, c->user, c->host, ch->name, ch->topic);
         } else {
             if (ch->topic[0])
-                send_reply(c, "%s %s :%s", c->nickname, ch->name, ch->topic);
+                send_reply(c, "332 %s %s :%s", c->nickname, ch->name, ch->topic);
             else
-                send_reply(c, "%s %s :No topic is set", c->nickname, ch->name);
+                send_reply(c, "331 %s %s :No topic is set", c->nickname, ch->name);
         }
     } else if (strcasecmp(cmd, "LIST") == 0) {
         for (Channel *ch = channels; ch; ch = ch->next)
             send_list(c, ch);
-        send_reply(c, "%s :End of LIST", c->nickname);
+        send_reply(c, "323 %s :End of LIST", c->nickname);
     } else if (strcasecmp(cmd, "NAMES") == 0) {
         char *chan = strtok(NULL, " ");
         if (chan) {
             Channel *ch = find_channel(chan);
             if (ch) send_names(c, ch);
-            else send_reply(c, "%s %s :No such channel", c->nickname, chan);
+            else send_reply(c, "403 %s %s :No such channel", c->nickname, chan);
         } else {
             for (int i = 0; i < c->channel_count; ++i)
                 send_names(c, c->channels[i]);
@@ -330,20 +360,20 @@ static void handle_line(Client *c, char *line) {
     } else if (strcasecmp(cmd, "MODE") == 0) {
         char *chan = strtok(NULL, " ");
         Channel *ch = find_channel(chan);
-        if (!ch) { send_reply(c, "%s %s :No such channel", c->nickname, chan); return; }
+        if (!ch) { send_reply(c, "403 %s %s :No such channel", c->nickname, chan); return; }
         char *flag = strtok(NULL, " ");
         if (!flag) {
-            send_reply(c, "%s %s +", c->nickname, ch->name);
+            send_reply(c, "324 %s %s +", c->nickname, ch->name);
         } else if (strcmp(flag, "+k") == 0) {
             char *key = strtok(NULL, " ");
-            if (!key) { send_reply(c, "%s MODE :Not enough parameters", c->nickname); return; }
+            if (!key) { send_reply(c, "461 %s MODE :Not enough parameters", c->nickname); return; }
             strncpy(ch->key, key, MAX_CHANNELLEN);
             broadcast_channel(ch, NULL, ":%s!%s@%s MODE %s +k %s", c->nickname, c->user, c->host, ch->name, key);
         } else if (strcmp(flag, "-k") == 0) {
             ch->key[0] = 0;
             broadcast_channel(ch, NULL, ":%s!%s@%s MODE %s -k", c->nickname, c->user, c->host, ch->name);
         } else {
-            send_reply(c, "%s %s :Unknown MODE flag", c->nickname, flag);
+            send_reply(c, "472 %s %s :Unknown MODE flag", c->nickname, flag);
         }
     } else if (strcasecmp(cmd, "MOTD") == 0) {
         send_motd(c);
@@ -360,33 +390,33 @@ static void handle_line(Client *c, char *line) {
             }
             nick = strtok(NULL, " ");
         }
-        send_reply(c, "%s :%s", c->nickname, buf);
+        send_reply(c, "303 %s :%s", c->nickname, buf);
     } else if (strcasecmp(cmd, "WHO") == 0) {
         char *chan = strtok(NULL, " ");
         Channel *ch = find_channel(chan);
         if (ch) {
             for (int i = 0; i < ch->member_count; ++i) {
                 Client *m = ch->members[i];
-                send_reply(c, "%s %s %s %s %s %s H :0 %s", c->nickname, ch->name, m->user, m->host, SERVER_NAME, m->nickname, m->realname);
+                send_reply(c, "352 %s %s %s %s %s %s H :0 %s", c->nickname, ch->name, m->user, m->host, SERVER_NAME, m->nickname, m->realname);
             }
-            send_reply(c, "%s %s :End of WHO list", c->nickname, ch->name);
+            send_reply(c, "315 %s %s :End of WHO list", c->nickname, ch->name);
         }
     } else if (strcasecmp(cmd, "WHOIS") == 0) {
         char *nick = strtok(NULL, " ");
         Client *u = find_client_by_nick(nick);
         if (u) {
-            send_reply(c, "%s %s %s %s * :%s", c->nickname, u->nickname, u->user, u->host, u->realname);
-            send_reply(c, "%s %s %s :%s", c->nickname, u->nickname, SERVER_NAME, SERVER_NAME);
+            send_reply(c, "311 %s %s %s %s * :%s", c->nickname, u->nickname, u->user, u->host, u->realname);
+            send_reply(c, "312 %s %s %s :%s", c->nickname, u->nickname, SERVER_NAME, SERVER_NAME);
             char buf[MAX_MSG] = "";
             for (int i = 0; i < u->channel_count; ++i) {
                 if (strlen(buf) + strlen(u->channels[i]->name) + 2 >= sizeof(buf)) break;
                 strncat(buf, u->channels[i]->name, sizeof(buf) - strlen(buf) - 1);
                 strncat(buf, " ", sizeof(buf) - strlen(buf) - 1);
             }
-            send_reply(c, "%s %s :%s", c->nickname, u->nickname, buf);
-            send_reply(c, "%s %s :End of WHOIS list", c->nickname, u->nickname);
+            send_reply(c, "319 %s %s :%s", c->nickname, u->nickname, buf);
+            send_reply(c, "318 %s %s :End of WHOIS list", c->nickname, u->nickname);
         } else {
-            send_reply(c, "%s %s :No such nick", c->nickname, nick);
+            send_reply(c, "401 %s %s :No such nick", c->nickname, nick);
         }
     } else if (strcasecmp(cmd, "AWAY") == 0) {
     } else if (strcasecmp(cmd, "WALLOPS") == 0) {
@@ -403,7 +433,7 @@ static void handle_line(Client *c, char *line) {
             send_raw(c, "CAP * NAK :%s", arg ? arg : "");
         }
     } else {
-        send_reply(c, "%s %s :Unknown command", c->nickname, cmd);
+        send_reply(c, "421 %s %s :Unknown command", c->nickname, cmd);
     }
 }
 
@@ -417,6 +447,7 @@ static void remove_client(Client *c) {
         while (prev && prev->next != c) prev = prev->next;
         if (prev) prev->next = c->next;
     }
+    log_event("user disconnected: %s (%s)", c->nickname[0]?c->nickname:"<unreg>", c->host);
     del_epoll(c->fd);
     if (c->fd >= 0) close(c->fd);
     c->fd = -1;
@@ -436,12 +467,28 @@ static void accept_new_client() {
     c->next = clients;
     clients = c;
     add_epoll(fd, EPOLLIN, c);
+    log_event("user connected: %s", c->host);
+}
+
+static int parse_args(int argc, char **argv, int *port, char **pass, int *log_enabled) {
+    *port = 6667;
+    *pass = NULL;
+    *log_enabled = 0;
+    for (int i = 1; i < argc; ++i) {
+        if (strcmp(argv[i], "--port") == 0 && i+1 < argc) {
+            *port = atoi(argv[++i]);
+        } else if (strcmp(argv[i], "--password") == 0 && i+1 < argc) {
+            *pass = argv[++i];
+        } else if (strcmp(argv[i], "--log") == 0) {
+            *log_enabled = 1;
+        }
+    }
+    return 0;
 }
 
 int main(int argc, char **argv) {
-    int port = 6667;
-    if (argc > 1) port = atoi(argv[1]);
-    if (argc > 2) password = argv[2];
+    int port;
+    parse_args(argc, argv, &port, &password, &logging_enabled);
 
     listen_fd = socket(AF_INET, SOCK_STREAM, 0);
     int opt = 1;
@@ -478,6 +525,7 @@ int main(int argc, char **argv) {
                 char *line, *saveptr;
                 line = strtok_r(c->readbuf, "\r\n", &saveptr);
                 while (line) {
+                    printf("%s\n",line);
                     handle_line(c, line);
                     line = strtok_r(NULL, "\r\n", &saveptr);
                 }