X-Git-Url: http://mj.ucw.cz/gitweb/?a=blobdiff_plain;f=nwhod.c;h=9407f6fa0334af796649741e361cc4b0e30969a8;hb=HEAD;hp=5d0cee02fae186192658bf61d73da082bef5f040;hpb=b62667ca593722d6a70fc8e107a2153501aff9a3;p=nwho.git

diff --git a/nwhod.c b/nwhod.c
index 5d0cee0..9407f6f 100644
--- a/nwhod.c
+++ b/nwhod.c
@@ -1,14 +1,14 @@
 /*
  *	The Remote User Information Daemon
  *
- *	(c) 1997--2010 Martin Mares <mj@ucw.cz>
+ *	(c) 1997--2017 Martin Mares <mj@ucw.cz>
  */
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <stdarg.h>
 #include <fcntl.h>
+#include <getopt.h>
 #include <unistd.h>
 #include <sys/socket.h>
 #include <netdb.h>
@@ -22,7 +22,7 @@
 #include <dirent.h>
 #include <errno.h>
 
-#include "net.h"
+#include "nwho.h"
 
 struct hostrec {
   struct hostrec *next;
@@ -31,23 +31,11 @@ struct hostrec {
   u32 addr;
 };
 
+static int do_not_daemonize;
 static int sock, port;
 static struct hostrec *first_host;
 static time_t now, last_local_scan;
-
-static void die(char *msg, ...) __attribute__((noreturn));
-
-static void
-die(char *msg, ...)
-{
-  va_list args;
-
-  va_start(args, msg);
-  fprintf(stderr, "nwhod: ");
-  vfprintf(stderr, msg, args);
-  fputc('\n', stderr);
-  exit(1);
-}
+static char hostname[64];
 
 static void
 net_init(char *name)
@@ -79,6 +67,9 @@ net_init(char *name)
       if (connect(sock, (struct sockaddr *) &sa, sizeof(sa)) < 0)
 	die("Cannot connect socket: %m");
     }
+
+  if (gethostname(hostname, sizeof(hostname)) < 0)
+    die("Unable to get my own host name: %m");
 }
 
 static void
@@ -101,8 +92,8 @@ scan_utmp(struct nwho_pkt *p, time_t now)
 	name[9] = 0;
 	strcpy(h->name, name);
 	h->login_time = htonl(now - u->ut_time);
-	sprintf(h->con, "%.7s", u->ut_line);
-	sprintf(device, "/dev/%s", u->ut_line);
+	snprintf(h->con, sizeof(h->con), "%s", u->ut_line);
+	snprintf(device, sizeof(device), "/dev/%s", u->ut_line);
 	if (stat(device, &st) < 0)
 	  continue;
 	h->mesg_y = !!(S_IWGRP & st.st_mode);
@@ -147,7 +138,7 @@ scan_load(struct nwho_pkt *p)
 static void
 make_pkt(struct nwho_pkt *pkt)
 {
-  bzero(pkt, sizeof(pkt));
+  bzero(pkt, sizeof(*pkt));
   pkt->magic = htonl(NWHO_MAGIC);
   pkt->local_time = htonl(now);
   scan_utmp(pkt, now);
@@ -170,8 +161,9 @@ cleanup(void)
 }
 
 static void
-save_pkt(char *name, struct nwho_pkt *pkt, int len)
+save_pkt(char *name, struct nwho_pkt *pkt)
 {
+  int len = nwho_pkt_size(pkt);
   int fd = open(name, O_WRONLY | O_CREAT, 0666);
   if (fd < 0)
     {
@@ -218,25 +210,23 @@ receive(void)
 
   if (!is_valid(sa.sin_addr.s_addr) || sa.sin_port != port)
     {
-      syslog(LOG_WARNING, "Received packet from invalid source %s.%d", inet_ntoa(sa.sin_addr), ntohs(sa.sin_port));
+      syslog(LOG_WARNING, "Received packet from invalid source %s:%d", inet_ntoa(sa.sin_addr), ntohs(sa.sin_port));
       return;
     }
 
-  if (r < n || r != n + ntohl(pkt.num_users)*sizeof(struct userinfo))
+  if (r < n ||
+      pkt.magic != htonl(NWHO_MAGIC) ||
+      ntohl(pkt.num_users) > MAX_USERS ||
+      r < nwho_pkt_size(&pkt))
     {
       syslog(LOG_WARNING, "Malformed packet from %s", inet_ntoa(sa.sin_addr));
       return;
     }
 
-  if (pkt.magic != htonl(NWHO_MAGIC))
-    {
-      syslog(LOG_WARNING, "Received ancient nwho packet from %s", inet_ntoa(sa.sin_addr));
-      return;
-    }
-
   for(e=first_host; e; e=e->next)
     if (e->addr == sa.sin_addr.s_addr)
       break;
+
   if (!e)
     {
       e = malloc(sizeof(struct hostrec));
@@ -250,8 +240,8 @@ receive(void)
       h = gethostbyaddr((char *) &sa.sin_addr, sizeof(sa.sin_addr), AF_INET);
       if (h)
 	{
-	  sprintf(e->name, "%.30s", h->h_name);
-	  for(c=e->name; *c; c++)
+	  snprintf(e->name, sizeof(e->name), "%s", h->h_name);
+	  for (c=e->name; *c; c++)
 	    if (*c == '.')
 	      {
 		*c = 0;
@@ -269,19 +259,16 @@ receive(void)
     }
 
   e->last_rec = now;
-  save_pkt(e->name, &pkt, r);
+  save_pkt(e->name, &pkt);
 }
 
 static void
 local_scan(void)
 {
   struct nwho_pkt pkt;
-  static char hostname[64];
 
   make_pkt(&pkt);
-  if (!hostname[0] && gethostname(hostname, sizeof(hostname)) < 0)
-    die("gethostname: %m");
-  save_pkt(hostname, &pkt, sizeof(pkt) - (MAX_USERS - ntohl(pkt.num_users))*sizeof(struct userinfo));
+  save_pkt(hostname, &pkt);
 }
 
 static void
@@ -306,6 +293,9 @@ do_tick(void)
 static void
 daemonize(void)
 {
+  if (do_not_daemonize)
+    return;
+
   pid_t pid = fork();
   if (pid < 0)
     die("Fork failed: %m");
@@ -359,23 +349,49 @@ client(char *serv)
     {
       now = time(NULL);
       make_pkt(&pkt);
-      if (send(sock, &pkt, sizeof(pkt) - (MAX_USERS - ntohl(pkt.num_users))*sizeof(struct userinfo), 0) < 0)
+      if (send(sock, &pkt, nwho_pkt_size(&pkt), 0) < 0)
 	syslog(LOG_ERR, "sendmsg: %m");
       sleep(DEFAULT_SEND_TIME);
     }
 }
 
+static void
+usage(void)
+{
+  fprintf(stderr, "Usage: nwhod [-d] [<server>]\n");
+  exit(1);
+}
+
 int
 main(int argc, char **argv)
 {
-  if (argc == 2)
-    client(argv[1]);
-  else if (argc == 1)
-    server();
-  else
+  if (argc == 2 && !strcmp(argv[1], "--version"))
     {
-      fprintf(stderr, "Usage: nwhod [<server>]\n");
-      return 1;
+      printf("nwho " STRINGIFY(VERSION) "\n");
+      return 0;
     }
+
+  int opt;
+  while ((opt = getopt(argc, argv, "d")) >= 0)
+    switch (opt)
+      {
+      case 'd':
+	do_not_daemonize = 1;
+	break;
+      default:
+	usage();
+      }
+
+  if (optind == argc-1)
+    {
+      if (argv[optind][0])
+	client(argv[optind]);
+      else
+	server();
+    }
+  else if (optind == argc)
+    server();
+  else
+    usage();
   return 0;
 }