Imported Upstream version 0.8.1 upstream/0.8.1

1 files changed, 235 insertions, 0 deletions

diff --git a/src/nm-policy-hosts.c b/src/nm-policy-hosts.c
new file mode 100644
index 00000000..7723c997
--- /dev/null
+++ b/src/nm-policy-hosts.c
@@ -0,0 +1,235 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- */
+/* NetworkManager -- Network link manager
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Copyright (C) 2004 - 2010 Red Hat, Inc.
+ */
+
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <netdb.h>
+#include <ctype.h>
+
+#include "nm-policy-hosts.h"
+#include "nm-logging.h"
+
+gboolean
+nm_policy_hosts_find_token (const char *line, const char *token)
+{
+	const char *start = line, *p = line;
+
+	g_return_val_if_fail (line != NULL, FALSE);
+	g_return_val_if_fail (token != NULL, FALSE);
+	g_return_val_if_fail (strlen (token) > 0, FALSE);
+
+	/* Walk through the line to find the next whitespace character */
+	while (p <= line + strlen (line)) {
+		if (isblank (*p) || (*p == '\0')) {
+			/* Token starts with 'start' and ends with 'end' */
+			if ((p > start) && *start && (p - start == strlen (token)) && !strncmp (start, token, (p - start)))
+				return TRUE; /* found */
+
+			/* not found; advance start and continue looking */
+			start = p + 1;
+		}
+		p++;
+	}
+
+	return FALSE;
+}
+
+static gboolean
+is_local_mapping (const char *str, const char *hostname)
+{
+	return (   !strncmp (str, "127.0.0.1", strlen ("127.0.0.1"))
+	        && nm_policy_hosts_find_token (str, hostname ? hostname : "localhost"));
+}
+
+GString *
+nm_policy_get_etc_hosts (const char **lines,
+                         gsize existing_len,
+                         const char *hostname,
+                         const char *fallback_hostname,
+                         GError **error)
+{
+	GString *contents = NULL;
+	const char **line;
+	gboolean found_host_nonlocal = FALSE;
+	gboolean found_host = FALSE;
+	gboolean found_localhost = FALSE;
+	gboolean initial_comments = TRUE;
+	gboolean added = FALSE;
+
+	g_return_val_if_fail (lines != NULL, FALSE);
+	g_return_val_if_fail (hostname != NULL, FALSE);
+
+	/* /etc/hosts needs at least two things:
+	 *
+	 * 1) current hostname mapped to any address
+	 * 2) 'localhost' mapped to 127.0.0.1
+	 *
+	 * If both these conditions exist in /etc/hosts, we don't need to bother
+	 * updating the file.
+	 */
+
+	/* Look for the two cases from above */
+	for (line = lines; lines && *line; line++) {
+		if (strlen (*line) && (*line[0] != '#')) {
+			if (nm_policy_hosts_find_token (*line, hostname)) {
+				if (!is_local_mapping (*line, "localhost")) {
+					/* hostname is not on a 127.0.0.1 line or the line does not
+					 * contain 'localhost'.
+					 */
+					found_host_nonlocal = TRUE;
+				}
+				found_host = TRUE;
+			}
+
+			if (is_local_mapping (*line, "localhost")) {
+				/* a 127.0.0.1 line containing 'localhost' */
+				found_localhost = TRUE;
+			}
+		}
+
+		if (found_localhost && found_host)
+			return NULL;  /* No update required */
+	}
+
+	contents = g_string_sized_new (existing_len ? existing_len + 100 : 200);
+	if (!contents) {
+		g_set_error_literal (error, 0, 0, "not enough memory");
+		return NULL;
+	}
+
+	/* Construct the new hosts file; replace any 127.0.0.1 entry that is at the
+	 * beginning of the file or right after initial comments and contains
+	 * the string 'localhost'.  If there is no 127.0.0.1 entry at the beginning
+	 * or after initial comments that contains 'localhost', add one there
+	 * and ignore any other 127.0.0.1 entries that contain 'localhost'.
+	 */
+	for (line = lines, initial_comments = TRUE; lines && *line; line++) {
+		gboolean add_line = TRUE;
+
+		/* This is the first line after the initial comments */
+		if (strlen (*line) && initial_comments && (*line[0] != '#')) {
+			initial_comments = FALSE;
+
+			/* If some other line contained the hostname but not 'localhost',
+			 * make a simple localhost mapping and assume the user knows what
+			 * they are doing with their manual hostname entry.  Otherwise if
+			 * the hostname wasn't found somewhere else, add it to the localhost
+			 * mapping line to make sure it's mapped to something.
+			 */
+			if (found_host_nonlocal)
+				g_string_append (contents, "127.0.0.1");
+			else
+				g_string_append_printf (contents, "127.0.0.1\t%s", hostname);
+
+			if (strcmp (hostname, fallback_hostname)) {
+				g_string_append_printf (contents, "\t%s", fallback_hostname);
+				/* Don't add a standalone 'localhost.localdomain' 127 mapping */
+				if (is_local_mapping (*line, fallback_hostname))
+					add_line = FALSE;
+			}
+
+			g_string_append (contents, "\tlocalhost\n");
+			added = TRUE;
+
+			/* Don't add the original line if it is a 'localhost' mapping */
+			if (is_local_mapping (*line, "localhost"))
+				add_line = FALSE;
+		}
+
+		if (add_line) {
+			g_string_append (contents, *line);
+			/* Only append the new line if this isn't the last line in the file */
+			if (*(line+1))
+				g_string_append_c (contents, '\n');
+		}
+	}
+
+	/* Hmm, /etc/hosts was empty for some reason */
+	if (!added) {
+		g_string_append (contents, "# Do not remove the following line, or various programs\n");
+		g_string_append (contents, "# that require network functionality will fail.\n");
+		g_string_append_printf (contents, "127.0.0.1\t%s\tlocalhost\n", fallback_hostname);
+	}
+
+	return contents;
+}
+
+gboolean
+nm_policy_hosts_update_etc_hosts (const char *hostname,
+                                  const char *fallback_hostname,
+                                  gboolean *out_changed)
+{
+	char *contents = NULL;
+	char **lines = NULL;
+	GError *error = NULL;
+	GString *new_contents = NULL;
+	gsize contents_len = 0;
+	gboolean success = FALSE;
+
+	g_return_val_if_fail (hostname != NULL, FALSE);
+	g_return_val_if_fail (out_changed != NULL, FALSE);
+
+	if (!g_file_get_contents (SYSCONFDIR "/hosts", &contents, &contents_len, &error)) {
+		nm_log_warn (LOGD_DNS, "couldn't read " SYSCONFDIR "/hosts: (%d) %s",
+		             error ? error->code : 0,
+		             (error && error->message) ? error->message : "(unknown)");
+		g_clear_error (&error);
+		return FALSE;
+	}
+
+	/* Get the new /etc/hosts contents */
+	lines = g_strsplit_set (contents, "\n\r", 0);
+	new_contents = nm_policy_get_etc_hosts ((const char **) lines,
+	                                        contents_len,
+	                                        hostname,
+	                                        fallback_hostname,
+	                                        &error);
+	g_strfreev (lines);
+	g_free (contents);
+
+	if (new_contents) {
+		nm_log_info (LOGD_DNS, "Updating /etc/hosts with new system hostname");
+
+		g_clear_error (&error);
+		/* And actually update /etc/hosts */
+		if (!g_file_set_contents (SYSCONFDIR "/hosts", new_contents->str, -1, &error)) {
+			nm_log_warn (LOGD_DNS, "couldn't update " SYSCONFDIR "/hosts: (%d) %s",
+			             error ? error->code : 0,
+			             (error && error->message) ? error->message : "(unknown)");
+			g_clear_error (&error);
+		} else {
+			success = TRUE;
+			*out_changed = TRUE;
+		}
+
+		g_string_free (new_contents, TRUE);
+	} else if (!error) {
+		/* No change required */
+		success = TRUE;
+	} else {
+		nm_log_warn (LOGD_DNS, "couldn't read " SYSCONFDIR "/hosts: (%d) %s",
+		             error->code, error->message ? error->message : "(unknown)");
+		g_clear_error (&error);
+	}
+
+	return success;
+}
+