1 files changed, 207 insertions, 0 deletions
diff --git a/send/sendd.c b/send/sendd.c
new file mode 100644
index 0000000..1b0c34e
--- /dev/null
+++ b/send/sendd.c
@@ -0,0 +1,207 @@
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <unistd.h>
+#include <string.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <ctype.h>
+#include <stdbool.h>
+
+#include "util.h"
+
+/*
+ * CONNECT MSG: "connect NAME" 
+ * SEND MSG: "msg XXXXX CONTENTS TIME"
+ * VALID MSG: 0 
+ * INVALID MSG: 1
+ */
+
+typedef struct client {
+	char *name;
+	int fd;
+	bool connected;
+} client;
+
+typedef struct msg {
+	client *sender;
+	char *contents;
+	time_t time;
+} msg;
+
+FILE *fout;
+int VALID = 0;
+int INVALID = 1;
+
+static int 
+init_daemon(int port) {
+	int s = socket(AF_INET, SOCK_STREAM, 0);
+
+	struct sockaddr_in addr = {AF_INET, htons(port), INADDR_ANY};
+
+	if (bind(s, (struct sockaddr *)&addr, sizeof(addr))) 
+		error("Failed to bind");
+
+	int flags = 10;
+	if (setsockopt(s, SOL_TCP, TCP_KEEPIDLE, (void *)&flags, sizeof(flags))) 
+		error("Couldn't set socket opts");
+
+	flags = 5;
+	if (setsockopt(s, SOL_TCP, TCP_KEEPCNT, (void *)&flags, sizeof(flags)))  
+		error("Couldn't set socket opts");
+
+	flags = 5;
+	if (setsockopt(s, SOL_TCP, TCP_KEEPINTVL, (void *)&flags, sizeof(flags))) 
+		error("Couldn't set socket opts");
+
+	listen(s, 10);
+	return s;
+}
+
+static void
+stop_daemon(int s) {
+	close(s);
+}
+
+static client *
+accept_client(int s) {
+	client *c = malloc(sizeof(client));
+	c->fd = accept(s, NULL, NULL);
+
+	char buf[256] = {0};
+	char *Pbuf = buf;
+	int n = recv(c->fd, buf, 256, 0);
+	if (n <= 0) {
+		warn("Client hungup");
+		close(c->fd);
+		return NULL;
+	}	
+	if (n <= 8) {
+		warn("Malformed connect msg");
+		close(c->fd);
+		return NULL;
+	}
+
+	if (memcmp(buf, "connect ", 8) != 0) {
+		warn("Malformed connect msg");
+		close(c->fd);
+		return NULL;
+	}
+
+	Pbuf += 8;
+	c->name = strdup(Pbuf);
+	c->connected = true;
+
+	return c;
+}
+
+static void 
+close_client(client *c) {
+	close(c->fd);
+	free(c->name);
+	free(c);
+}
+
+static msg*
+recv_msg(client *c) {
+	char buf[11] = {0};
+	char *Pbuf = buf + 4;
+	int n = recv(c->fd, buf, 10, 0);
+	if (n <= 0) {
+		warn("Client hungup");
+		close(c->fd);
+		c->connected = false;
+		return NULL;
+	}	
+	if (n < 10) {
+		warn("Malformed msg msg");
+		send(c->fd, &INVALID, sizeof(int), 0);
+		return NULL;
+	}
+	if (memcmp(buf, "msg ", 4) != 0) {
+		warn("Malformed msg msg");
+		send(c->fd, &INVALID, sizeof(int), 0);
+		return NULL;
+	}
+	for (int i = 4; buf[i] != 0 && i < 9; i++) {
+		if (!isdigit(buf[i])) {
+			warn("Malformed msg msg");
+			send(c->fd, &INVALID, sizeof(int), 0);
+			return NULL;
+		}
+	}
+
+	int len = atoi(Pbuf);
+	char *contents = malloc(len);
+	memset(contents, 0, len);
+
+	n = recv(c->fd, contents, len, 0);
+	if (n <= 0) {
+		warn("Client hungup");
+		c->connected = false;
+		close(c->fd);
+		return NULL;
+	}
+
+	msg *m = malloc(sizeof(msg));
+	m->sender = c;
+	m->contents = contents;
+
+	time_t t;
+	n = recv(c->fd, &t, sizeof(time_t), 0);
+	if (n <= 0) {
+		warn("Client hungup");
+		c->connected = false;
+		close(c->fd);
+		return NULL;
+	}
+	m->time = t;
+
+	send(c->fd, &VALID, sizeof(int), 0);
+
+	return m;
+}
+
+static void
+free_msg(msg *m) {
+	free(m->contents);
+	free(m);
+}
+
+static void
+msg_loop(client *c) {
+	msg *m;
+	while (c->connected && (m = recv_msg(c))) {
+		fprintf(fout, "%lld:%s:%s\n", m->time, m->sender->name, m->contents);
+		free_msg(m);
+	}
+	close_client(c);
+	exit(0);
+}
+
+int
+main(int argc, char **argv) {
+	char *out;
+	if (argc <= 1)
+		out = "/dev/stdout";
+	else 
+		out = argv[1];
+
+	if (!(fout = fopen(out, "w"))) 
+		error("Couldn't open outfile");
+
+	int s = init_daemon(1543);
+
+	pid_t pid;
+	for (;;) {
+		client *c = accept_client(s);
+		if ((pid = fork()) == 0) 
+			msg_loop(c);
+		else 
+			continue;
+	}
+
+	stop_daemon(s);
+}