o Add support for wall -g. This will send a message to all members of

a given group.
o Minor code style cleanups while I'm here

Reviewed by: bde, kris, markm, audit@

usr.bin/wall/ttymsg.c

@@ -59,26 +59,23 @@ static const char rcsid[] =
  * ignored (exclusive-use, lack of permission, etc.).
  */
 char *
-ttymsg(iov, iovcnt, line, tmout)
-	struct iovec *iov;
-	int iovcnt;
-	char *line;
-	int tmout;
+ttymsg(struct iovec *iov, int iovcnt, const char *line, int tmout)
 {
+	struct iovec localiov[7];
+	int cnt, fd, left, wret;
 	static char device[MAXNAMLEN] = _PATH_DEV;
 	static char errbuf[1024];
-	register int cnt, fd, left, wret;
-	struct iovec localiov[7];
-	int forked = 0;
+	int forked;
 
+	forked = 0;
 	if (iovcnt > sizeof(localiov) / sizeof(localiov[0]))
 		return ("too many iov's (change code in wall/ttymsg.c)");
 
-	(void) strcpy(device + sizeof(_PATH_DEV) - 1, line);
+	strlcat(device, line, sizeof(device));
 	if (strchr(device + sizeof(_PATH_DEV) - 1, '/')) {
 		/* A slash is an attempt to break security... */
-		(void) snprintf(errbuf, sizeof(errbuf), "'/' in \"%s\"",
-		    device);
+		(void) snprintf(errbuf, sizeof(errbuf),
+		    "Too many '/' in \"%s\"", device);
 		return (errbuf);
 	}
 
@@ -89,8 +86,8 @@ ttymsg(iov, iovcnt, line, tmout)
 	if ((fd = open(device, O_WRONLY|O_NONBLOCK, 0)) < 0) {
 		if (errno == EBUSY || errno == EACCES)
 			return (NULL);
-		(void) snprintf(errbuf, sizeof(errbuf),
-		    "%s: %s", device, strerror(errno));
+		(void) snprintf(errbuf, sizeof(errbuf), "%s: %s", device,
+		    strerror(errno));
 		return (errbuf);
 	}
 
@@ -104,7 +101,7 @@ ttymsg(iov, iovcnt, line, tmout)
 		if (wret >= 0) {
 			left -= wret;
 			if (iov != localiov) {
-				bcopy(iov, localiov,
+				bcopy(iov, localiov, 
 				    iovcnt * sizeof(struct iovec));
 				iov = localiov;
 			}

usr.bin/wall/wall.1

@@ -40,6 +40,7 @@
 .Nd write a message to users
 .Sh SYNOPSIS
 .Nm
+.Op Fl g Ar group
 .Op Ar file
 .Sh DESCRIPTION
 .Nm Wall
@@ -52,6 +53,12 @@ Only the super-user can write on the
 terminals of users who have chosen
 to deny messages or are using a program which
 automatically denies messages.
+.Bl -tag -width indent
+.It Fl g
+Send messages to users in this group.  This option may be specified
+multiple times, and any user in any of the specified groups will
+receive the message.
+.El
 .Sh SEE ALSO
 .Xr mesg 1 ,
 .Xr talk 1 ,

usr.bin/wall/wall.c

@@ -56,6 +56,7 @@ static const char rcsid[] =
 
 #include <ctype.h>
 #include <err.h>
+#include <grp.h>
 #include <locale.h>
 #include <paths.h>
 #include <pwd.h>
@@ -66,38 +67,54 @@ static const char rcsid[] =
 #include <unistd.h>
 #include <utmp.h>
 
-void	makemsg __P((char *));
-static void usage __P((void));
-char   *ttymsg __P((struct iovec *, int, char *, int));
+static void makemsg(char *);
+static void usage(void);
+char   *ttymsg(struct iovec *, int, const char *, int);
 
 #define	IGNOREUSER	"sleeper"
 
+struct wallgroup {
+	struct wallgroup *next;
+	char		*name;
+	gid_t		gid;
+} *grouplist;
 int nobanner;
 int mbufsize;
 char *mbuf;
 
-/* ARGSUSED */
 int
-main(argc, argv)
-	int argc;
-	char **argv;
+main(int argc, char *argv[])
 {
-	int ch;
 	struct iovec iov;
 	struct utmp utmp;
+	gid_t grps[NGROUPS_MAX];
+	int ch;
+	int ingroup, ngrps, i;
 	FILE *fp;
+	struct wallgroup *g;
+	struct group *grp;
 	char *p;
+	struct passwd *pw;
 	char line[sizeof(utmp.ut_line) + 1];
+	char username[sizeof(utmp.ut_name) + 1];
 
+	ingroup = 0;
 	(void)setlocale(LC_CTYPE, "");
 
-	while ((ch = getopt(argc, argv, "n")) != -1)
+	while ((ch = getopt(argc, argv, "g:n")) != -1)
 		switch (ch) {
 		case 'n':
 			/* undoc option for shutdown: suppress banner */
 			if (geteuid() == 0)
 				nobanner = 1;
 			break;
+		case 'g':
+			g = (struct wallgroup *)malloc(sizeof *g);
+			g->next = grouplist;
+			g->name = optarg;
+			g->gid = -1;
+			grouplist = g;
+			break;
 		case '?':
 		default:
 			usage();
@@ -107,6 +124,12 @@ main(argc, argv)
 	if (argc > 1)
 		usage();
 
+	for (g = grouplist; g; g = g->next) {
+		grp = getgrnam(g->name);
+		if (grp)
+			g->gid = grp->gr_gid;
+	}
+
 	makemsg(*argv);
 
 	if (!(fp = fopen(_PATH_UTMP, "r")))
@@ -118,6 +141,24 @@ main(argc, argv)
 		if (!utmp.ut_name[0] ||
 		    !strncmp(utmp.ut_name, IGNOREUSER, sizeof(utmp.ut_name)))
 			continue;
+		if (grouplist) {
+			strlcpy(username, utmp.ut_name, sizeof(utmp.ut_name));
+			pw = getpwnam(username);
+			if (!pw)
+				continue;
+			ngrps = getgroups(pw->pw_gid, grps);
+			for (g = grouplist; g && ingroup == 0; g = g->next) {
+				if (g->gid == -1)
+					continue;
+				if (g->gid == pw->pw_gid)
+					ingroup = 1;
+				for (i = 0; i < ngrps && ingroup == 0; i++)
+					if (g->gid == grps[i])
+						ingroup = 1;
+			}
+			if (ingroup == 0)
+				continue;
+		}
 		strncpy(line, utmp.ut_line, sizeof(utmp.ut_line));
 		line[sizeof(utmp.ut_line)] = '\0';
 		if ((p = ttymsg(&iov, 1, line, 60*5)) != NULL)
@@ -134,11 +175,10 @@ usage()
 }
 
 void
-makemsg(fname)
-	char *fname;
+makemsg(char *fname)
 {
-	register int cnt;
-	register unsigned char ch;
+	int cnt;
+	unsigned char ch;
 	struct tm *lt;
 	struct passwd *pw;
 	struct stat sbuf;