1 files changed, 115 insertions, 0 deletions
diff --git a/lib/libutil/trimdomain.c b/lib/libutil/trimdomain.c
new file mode 100644
index 0000000..85c27e0
--- /dev/null
+++ b/lib/libutil/trimdomain.c
@@ -0,0 +1,115 @@
+/*-
+ * Copyright (c) 2001 Brian Somers <brian@Awfulhak.org>
+ *   Based on original work by Atsushi Murai <amurai@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+
+#include <libutil.h>
+#include <string.h>
+#include <unistd.h>
+
+static int	isDISP(const char *);
+
+/*-
+ * Trim the current domain name from fullhost, but only if the result
+ * is less than or equal to hostsize in length.
+ *
+ * This function understands $DISPLAY type fullhosts.
+ *
+ * For example:
+ *
+ *     trimdomain("abcde.my.domain", 5)       ->   "abcde"
+ *     trimdomain("abcde.my.domain", 4)       ->   "abcde.my.domain"
+ *     trimdomain("abcde.my.domain:0.0", 9)   ->   "abcde:0.0"
+ *     trimdomain("abcde.my.domain:0.0", 8)   ->   "abcde.my.domain:0.0"
+ */
+void
+trimdomain(char *fullhost, int hostsize)
+{
+	static size_t dlen;
+	static int first = 1;
+	static char domain[MAXHOSTNAMELEN];
+	char *end, *s;
+	size_t len;
+
+	if (first) {
+		/* XXX: Should we assume that our domain is this persistent ? */
+		first = 0;
+		if (gethostname(domain, sizeof(domain) - 1) == 0 &&
+		    (s = strchr(domain, '.')) != NULL)
+			memmove(domain, s + 1, strlen(s + 1) + 1);
+		else
+			domain[0] = '\0';
+		dlen = strlen(domain);
+	}
+
+	if (domain[0] == '\0')
+		return;
+
+	s = fullhost;
+	end = s + hostsize + 1;
+	if ((s = memchr(s, '.', (size_t)(end - s))) != NULL) {
+		if (strncasecmp(s + 1, domain, dlen) == 0) {
+			if (s[dlen + 1] == '\0') {
+				/* Found -- lose the domain. */
+				*s = '\0';
+			} else if (s[dlen + 1] == ':' &&
+			    isDISP(s + dlen + 2) &&
+			    (len = strlen(s + dlen + 1)) < (size_t)(end - s)) {
+				/* Found -- shuffle the DISPLAY back. */
+				memmove(s, s + dlen + 1, len + 1);
+			}
+		}
+	}
+}
+
+/*
+ * Is the given string NN or NN.NN where ``NN'' is an all-numeric string ?
+ */
+static int
+isDISP(const char *disp)
+{
+	size_t w;
+	int res;
+
+	w = strspn(disp, "0123456789");
+	res = 0;
+	if (w > 0) {
+		if (disp[w] == '\0')
+			res = 1;	/* NN */
+		else if (disp[w] == '.') {
+			disp += w + 1;
+			w = strspn(disp, "0123456789");
+			if (w > 0 && disp[w] == '\0')
+				res = 1;	/* NN.NN */
+		}
+	}
+	return (res);
+}