Use fgetln(3) to read lines from configuration files (ftpusers, ftphosts.)

Thus lines of any length can be handled, unlike before.

Don't assume that each line read from the files ends with a newline.

As a side effect in inithosts(), don't use automatic buffer at all,
utilize malloc(3) when getting local host name instead.

PR:		misc/21494
Reviewed by:	maxim, mikeh
MFC after:	1 month

1 files changed, 78 insertions, 48 deletions

diff --git a/libexec/ftpd/ftpd.c b/libexec/ftpd/ftpd.c
index 7e5496b..6b6fc5d 100644
--- a/libexec/ftpd/ftpd.c
+++ b/libexec/ftpd/ftpd.c
@@ -651,20 +651,24 @@ sigquit(int signo)
 static void
 inithosts(void)
 {
+	size_t len;
 	FILE *fp;
-	char *cp;
+	char *cp, *mp, *line;
+	char *hostname;
 	struct ftphost *hrp, *lhrp;
-	char line[1024];
 	struct addrinfo hints, *res, *ai;
 
 	/*
 	 * Fill in the default host information
 	 */
-	if (gethostname(line, sizeof(line)) < 0)
-		line[0] = '\0';
-	if ((hrp = malloc(sizeof(struct ftphost))) == NULL ||
-	    (hrp->hostname = strdup(line)) == NULL)
+	if ((hostname = malloc(MAXHOSTNAMELEN)) == NULL)
 		fatalerror("Ran out of memory.");
+	if (gethostname(hostname, MAXHOSTNAMELEN) < 0)
+		hostname[0] = '\0';
+	hostname[MAXHOSTNAMELEN - 1] = '\0';
+	if ((hrp = malloc(sizeof(struct ftphost))) == NULL)
+		fatalerror("Ran out of memory.");
+	hrp->hostname = hostname;
 	hrp->hostinfo = NULL;
 
 	memset(&hints, 0, sizeof(hints));
@@ -684,28 +688,33 @@ inithosts(void)
 		void *addr;
 		struct hostent *hp;
 
-		while (fgets(line, sizeof(line), fp) != NULL) {
+		while ((line = fgetln(fp, &len)) != NULL) {
 			int	i, hp_error;
 
-			if ((cp = strchr(line, '\n')) == NULL) {
-				/* ignore long lines */
-				while (fgets(line, sizeof(line), fp) != NULL &&
-					strchr(line, '\n') == NULL)
-					;
+			/* skip comments */
+			if (line[0] == '#')
 				continue;
+			if (line[len - 1] == '\n') {
+				line[len - 1] = '\0';
+				mp = NULL;
+			} else {
+				if ((mp = malloc(len + 1)) == NULL)
+					fatalerror("Ran out of memory.");
+				memcpy(mp, line, len);
+				mp[len] = '\0';
+				line = mp;
 			}
-			*cp = '\0';
 			cp = strtok(line, " \t");
-			/* skip comments and empty lines */
-			if (cp == NULL || line[0] == '#')
-				continue;
+			/* skip empty lines */
+			if (cp == NULL)
+				goto nextline;
 
 			hints.ai_flags = 0;
 			hints.ai_family = AF_UNSPEC;
 			hints.ai_flags = AI_PASSIVE;
 			error = getaddrinfo(cp, NULL, &hints, &res);
 			if (error != NULL)
-				continue;
+				goto nextline;
 			for (ai = res; ai != NULL && ai->ai_addr != NULL;
 			     ai = ai->ai_next) {
 
@@ -727,7 +736,7 @@ inithosts(void)
 			}
 			if (hrp == NULL) {
 				if ((hrp = malloc(sizeof(struct ftphost))) == NULL)
-					continue;
+					goto nextline;
 				/* defaults */
 				hrp->statfile = _PATH_FTPDSTATFILE;
 				hrp->welcome  = _PATH_FTPWELCOME;
@@ -759,7 +768,7 @@ inithosts(void)
 				if (hrp->hostinfo != NULL)
 					freeaddrinfo(hrp->hostinfo);
 				free(hrp);
-				continue;
+				goto nextline;
 				/* NOTREACHED */
 			}
 			if ((hp = getipnodebyaddr((char*)addr, addrsize,
@@ -804,6 +813,9 @@ inithosts(void)
 			/* XXX: re-initialization for getaddrinfo() loop */
 			cp = strtok(line, " \t");
 		      }
+nextline:
+			if (mp)
+				free(mp);
 		}
 		(void) fclose(fp);
 	}
@@ -1013,42 +1025,60 @@ checkuser(char *fname, char *name, int pwset)
 {
 	FILE *fd;
 	int found = 0;
-	char *p, line[BUFSIZ];
+	size_t len;
+	char *line, *mp, *p;
 
 	if ((fd = fopen(fname, "r")) != NULL) {
-		while (!found && fgets(line, sizeof(line), fd) != NULL)
-			if ((p = strchr(line, '\n')) != NULL) {
-				*p = '\0';
-				if (line[0] == '#')
-					continue;
+		while (!found && (line = fgetln(fd, &len)) != NULL) {
+			/* skip comments */
+			if (line[0] == '#')
+				continue;
+			if (line[len - 1] == '\n') {
+				line[len - 1] = '\0';
+				mp = NULL;
+			} else {
+				if ((mp = malloc(len + 1)) == NULL)
+					fatalerror("Ran out of memory.");
+				memcpy(mp, line, len);
+				mp[len] = '\0';
+				line = mp;
+			}
+			/* avoid possible leading and trailing whitespace */
+			p = strtok(line, " \t");
+			/* skip empty lines */
+			if (p == NULL)
+				goto nextline;
+			/*
+			 * if first chr is '@', check group membership
+			 */
+			if (p[0] == '@') {
+				int i = 0;
+				struct group *grp;
+
+				if ((grp = getgrnam(p+1)) == NULL)
+					goto nextline;
 				/*
-				 * if first chr is '@', check group membership
+				 * Check user's default group
 				 */
-				if (line[0] == '@') {
-					int i = 0;
-					struct group *grp;
-
-					if ((grp = getgrnam(line+1)) == NULL)
-						continue;
-					/*
-					 * Check user's default group
-					 */
-					if (pwset && grp->gr_gid == pw->pw_gid)
-						found = 1;
-					/*
-					 * Check supplementary groups
-					 */
-					while (!found && grp->gr_mem[i])
-						found = strcmp(name,
-							grp->gr_mem[i++])
-							== 0;
-				}
+				if (pwset && grp->gr_gid == pw->pw_gid)
+					found = 1;
 				/*
-				 * Otherwise, just check for username match
+				 * Check supplementary groups
 				 */
-				else
-					found = strcmp(line, name) == 0;
+				while (!found && grp->gr_mem[i])
+					found = strcmp(name,
+						grp->gr_mem[i++])
+						== 0;
 			}
+			/*
+			 * Otherwise, just check for username match
+			 */
+			else
+				found = strcmp(p, name) == 0;
+nextline:
+			if (mp)
+				free(mp);
+		}
 		(void) fclose(fd);
 	}
 	return (found);