6 files changed, 148 insertions, 39 deletions

diff --git a/ChangeLog.txt b/ChangeLog.txt
index 73a12d4..033fdcf 100644
--- a/ChangeLog.txt
+++ b/ChangeLog.txt
@@ -1,6 +1,8 @@
 2018-01-16:
 	* (seebs) rework the LINKAT case significantly but now
 	  it's actually probably right.
+	* (<zboszor@pr.hu>) handle extremely long group names
+	  in getgrnam and similar functions.
 
 2017-12-22:
 	* (seebs) handle the pathological case of LINKAT with
diff --git a/ports/darwin/guts/getgrouplist.c b/ports/darwin/guts/getgrouplist.c
index 85fccc9..c5950bd 100644
--- a/ports/darwin/guts/getgrouplist.c
+++ b/ports/darwin/guts/getgrouplist.c
@@ -9,23 +9,47 @@
 
 	int found = 0;
 	int found_group = 0;
-	char buf[PSEUDO_PWD_MAX];
-	struct group grp, *gbuf = &grp;
-
-	setgrent();
-	while ((rc = wrap_getgrent_r(gbuf, buf, PSEUDO_PWD_MAX, &gbuf)) == 0) {
-		int i = 0;
-		for (i = 0; gbuf->gr_mem[i]; ++i) {
-			if (!strcmp(gbuf->gr_mem[i], name)) {
-				if (found < *ngroups)
-					groups[found] = gbuf->gr_gid;
-				++found;
-				if ((int) gbuf->gr_gid == basegid)
-					found_group = 1;
+	size_t buflen = PSEUDO_PWD_MAX;
+	char *buf = NULL;
+	struct group grp;
+
+	rc = ERANGE;
+
+	do {
+		struct group *gbuf = &grp;
+		char *new_buf = buf;
+
+		if (rc == ERANGE)
+			new_buf = realloc(buf, buflen);
+
+		if (!new_buf) {
+			rc = ENOMEM;
+			break;
+		}
+
+		buf = new_buf;
+
+		found = 0;
+		found_group = 0;
+		setgrent();
+		while ((rc = wrap_getgrent_r(gbuf, buf, buflen, &gbuf)) == 0) {
+			int i = 0;
+			for (i = 0; gbuf->gr_mem[i]; ++i) {
+				if (!strcmp(gbuf->gr_mem[i], name)) {
+					if (found < *ngroups)
+						groups[found] = gbuf->gr_gid;
+					++found;
+					if ((int) gbuf->gr_gid == basegid)
+						found_group = 1;
+				}
 			}
 		}
-	}
-	endgrent();
+		endgrent();
+
+		if (rc == ERANGE)
+			buflen = buflen << 1;
+	} while (rc == ERANGE);
+	free(buf);
 	if (!found_group) {
 		if (found < *ngroups)
 			groups[found] = basegid;
diff --git a/ports/linux/guts/getgrouplist.c b/ports/linux/guts/getgrouplist.c
index 3489ec9..8b16e47 100644
--- a/ports/linux/guts/getgrouplist.c
+++ b/ports/linux/guts/getgrouplist.c
@@ -9,23 +9,47 @@
 
 	int found = 0;
 	int found_group = 0;
-	char buf[PSEUDO_PWD_MAX];
-	struct group grp, *gbuf = &grp;
-
-	setgrent();
-	while ((rc = wrap_getgrent_r(gbuf, buf, PSEUDO_PWD_MAX, &gbuf)) == 0) {
-		int i = 0;
-		for (i = 0; gbuf->gr_mem[i]; ++i) {
-			if (!strcmp(gbuf->gr_mem[i], user)) {
-				if (found < *ngroups)
-					groups[found] = gbuf->gr_gid;
-				++found;
-				if (gbuf->gr_gid == group)
-					found_group = 1;
+	size_t buflen = PSEUDO_PWD_MAX;
+	char *buf = NULL;
+	struct group grp;
+
+	rc = ERANGE;
+
+	do {
+		struct group *gbuf = &grp;
+		char *new_buf = buf;
+
+		if (rc == ERANGE)
+			new_buf = realloc(buf, buflen);
+
+		if (!new_buf) {
+			rc = ENOMEM;
+			break;
+		}
+
+		buf = new_buf;
+
+		found = 0;
+		found_group = 0;
+		setgrent();
+		while ((rc = wrap_getgrent_r(gbuf, buf, buflen, &gbuf)) == 0) {
+			int i = 0;
+			for (i = 0; gbuf->gr_mem[i]; ++i) {
+				if (!strcmp(gbuf->gr_mem[i], user)) {
+					if (found < *ngroups)
+						groups[found] = gbuf->gr_gid;
+					++found;
+					if (gbuf->gr_gid == group)
+						found_group = 1;
+				}
 			}
 		}
-	}
-	endgrent();
+		endgrent();
+
+		if (rc == ERANGE)
+			buflen = buflen << 1;
+	} while (rc == ERANGE);
+	free(buf);
 	if (!found_group) {
 		if (found < *ngroups)
 			groups[found] = group;
diff --git a/ports/uids_generic/guts/getgrent.c b/ports/uids_generic/guts/getgrent.c
index e8e07f5..d6592e6 100644
--- a/ports/uids_generic/guts/getgrent.c
+++ b/ports/uids_generic/guts/getgrent.c
@@ -7,10 +7,30 @@
  *	struct group * rc = NULL;
  */
 	static struct group grp;
-	static char grbuf[PSEUDO_PWD_MAX];
-	int r_rc;
+	static size_t grbuflen = PSEUDO_PWD_MAX;
+	static char *grbuf = NULL;
+	int r_rc = ERANGE;
+
+	do {
+		char *new_grbuf = grbuf;
+
+		if (r_rc == ERANGE)
+			new_grbuf = realloc(grbuf, grbuflen);
+
+		if (!new_grbuf) {
+			r_rc = ENOMEM;
+			break;
+		}
+
+		grbuf = new_grbuf;
+
+		r_rc = wrap_getgrent_r(&grp, grbuf, grbuflen, &rc);
+
+		if (r_rc == ERANGE)
+			grbuflen = grbuflen << 1;
+
+	} while (r_rc == ERANGE);
 
-	r_rc = wrap_getgrent_r(&grp, grbuf, PSEUDO_PWD_MAX, &rc);
 	/* different error return conventions */
 	if (r_rc != 0) {
 		errno = r_rc;
diff --git a/ports/uids_generic/guts/getgrgid.c b/ports/uids_generic/guts/getgrgid.c
index c1824e7..0d3dafb 100644
--- a/ports/uids_generic/guts/getgrgid.c
+++ b/ports/uids_generic/guts/getgrgid.c
@@ -7,10 +7,30 @@
  *	struct group * rc = NULL;
  */
 	static struct group grp;
-	static char grbuf[PSEUDO_PWD_MAX];
-	int r_rc;
+	static size_t grbuflen = PSEUDO_PWD_MAX;
+	static char *grbuf = NULL;
+	int r_rc = ERANGE;
+
+	do {
+		char *new_grbuf = grbuf;
+
+		if (r_rc == ERANGE)
+			new_grbuf = realloc(grbuf, grbuflen);
+
+		if (!new_grbuf) {
+			r_rc = ENOMEM;
+			break;
+		}
+
+		grbuf = new_grbuf;
+
+		r_rc = wrap_getgrgid_r(gid, &grp, grbuf, grbuflen, &rc);
+
+		if (r_rc == ERANGE)
+			grbuflen = grbuflen << 1;
+
+	} while (r_rc == ERANGE);
 
-	r_rc = wrap_getgrgid_r(gid, &grp, grbuf, PSEUDO_PWD_MAX, &rc);
 	/* different error return conventions */
 	if (r_rc != 0) {
 		errno = r_rc;
diff --git a/ports/uids_generic/guts/getgrnam.c b/ports/uids_generic/guts/getgrnam.c
index 0e26444..19006ad 100644
--- a/ports/uids_generic/guts/getgrnam.c
+++ b/ports/uids_generic/guts/getgrnam.c
@@ -8,10 +8,29 @@
  */
 
 	static struct group grp;
-	static char grbuf[PSEUDO_PWD_MAX];
-	int r_rc;
+	static size_t grbufsz = PSEUDO_PWD_MAX;
+	static char *grbuf = NULL;
+	int r_rc = ERANGE;
+
+	do {
+		char *new_grbuf = grbuf;
+
+		if (r_rc != 0)
+			new_grbuf = realloc(grbuf, grbufsz);
+
+		if (!new_grbuf) {
+			r_rc = ENOMEM;
+			break;
+		}
+
+		grbuf = new_grbuf;
+
+		r_rc = wrap_getgrnam_r(name, &grp, grbuf, grbufsz, &rc);
+
+		if (r_rc == ERANGE)
+			grbufsz = grbufsz << 1;
+	} while (r_rc == ERANGE);
 
-	r_rc = wrap_getgrnam_r(name, &grp, grbuf, PSEUDO_PWD_MAX, &rc);
 	/* different error return conventions */
 	if (r_rc != 0) {
 		errno = r_rc;