hostname: don't override the hostname with localhost if it is already set and /etc...

[elogind.git] / src / hostname-setup.c

diff --git a/src/hostname-setup.c b/src/hostname-setup.c
index 3b988d4c8b68dfdad2c25c545d736e0adb4b470a..e9869bb4dff4d64f6d8d1500bd956815fc38cd26 100644 (file)
--- a/src/hostname-setup.c
+++ b/src/hostname-setup.c
@@ -1,4 +1,4 @@
-/*-*- Mode: C; c-basic-offset: 8 -*-*/
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
 
 /***
   This file is part of systemd.
@@ -30,14 +30,10 @@
 #include "util.h"
 #include "log.h"
 
-#define LINE_MAX 4096
-
-#if defined(TARGET_FEDORA)
+#if defined(TARGET_FEDORA) || defined(TARGET_ALTLINUX) || defined(TARGET_MANDRIVA)
 #define FILENAME "/etc/sysconfig/network"
-#elif defined(TARGET_SUSE) || defined(TARGET_SLACKWARE)
+#elif defined(TARGET_SUSE) || defined(TARGET_SLACKWARE) || defined(TARGET_FRUGALWARE)
 #define FILENAME "/etc/HOSTNAME"
-#elif defined(TARGET_DEBIAN)
-#define FILENAME "/etc/hostname"
 #elif defined(TARGET_ARCH)
 #define FILENAME "/etc/rc.conf"
 #elif defined(TARGET_GENTOO)
@@ -52,7 +48,8 @@ static char* strip_bad_chars(char *s) {
                     (*p >= 'A' && *p <= 'Z') ||
                     (*p >= '0' && *p <= '9') ||
                     *p == '-' ||
-                    *p == '_')
+                    *p == '_' ||
+                    *p == '.')
                         *(d++) = *p;
 
         *d = 0;
@@ -60,9 +57,37 @@ static char* strip_bad_chars(char *s) {
         return s;
 }
 
-static int read_hostname(char **hn) {
+static int read_and_strip_hostname(const char *path, char **hn) {
+        char *s, *k;
+        int r;
+
+        assert(path);
+        assert(hn);
+
+        if ((r = read_one_line_file(path, &s)) < 0)
+                return r;
+
+        k = strdup(strstrip(s));
+        free(s);
+
+        if (!k)
+                return -ENOMEM;
+
+        strip_bad_chars(k);
 
-#if defined(TARGET_FEDORA) || defined(TARGET_ARCH) || defined(TARGET_GENTOO)
+        if (k[0] == 0) {
+                free(k);
+                return -ENOENT;
+        }
+
+        *hn = k;
+
+        return 0;
+}
+
+static int read_distro_hostname(char **hn) {
+
+#if defined(TARGET_FEDORA) || defined(TARGET_ARCH) || defined(TARGET_GENTOO) || defined(TARGET_ALTLINUX) || defined(TARGET_MANDRIVA)
         int r;
         FILE *f;
 
@@ -102,67 +127,84 @@ static int read_hostname(char **hn) {
                 }
 
                 *hn = k;
-                break;
+                r = 0;
+                goto finish;
         }
 
-        r = 0;
+        r = -ENOENT;
 
 finish:
         fclose(f);
         return r;
 
-#elif defined(TARGET_SUSE) || defined(TARGET_DEBIAN) || defined(TARGET_SLACKWARE)
+#elif defined(TARGET_SUSE) || defined(TARGET_SLACKWARE) || defined(TARGET_FRUGALWARE)
+        return read_and_strip_hostname(FILENAME, hn);
+#else
+        return -ENOENT;
+#endif
+}
+
+static int read_hostname(char **hn) {
         int r;
-        char *s, *k;
 
         assert(hn);
 
-        if ((r = read_one_line_file(FILENAME, &s)) < 0)
-                return r;
-
-        k = strdup(strstrip(s));
-        free(s);
+        /* First, try to load the generic hostname configuration file,
+         * that we support on all distributions */
 
-        if (!k)
-                return -ENOMEM;
+        if ((r = read_and_strip_hostname("/etc/hostname", hn)) < 0) {
 
-        strip_bad_chars(k);
+                if (r == -ENOENT)
+                        return read_distro_hostname(hn);
 
-        if (k[0] == 0) {
-                free(k);
-                return -ENOENT;
+                return r;
         }
 
-        *hn = k;
-
-#else
-#warning "Don't know how to read the hostname"
-
-        return -ENOENT;
-#endif
-
         return 0;
 }
 
 int hostname_setup(void) {
         int r;
-        char *hn;
+        char *b = NULL;
+        const char *hn = NULL;
 
-        if ((r = read_hostname(&hn)) < 0) {
-                if (r != -ENOENT)
+        if ((r = read_hostname(&b)) < 0) {
+                if (r == -ENOENT)
+                        log_info("No hostname configured.");
+                else
                         log_warning("Failed to read configured hostname: %s", strerror(-r));
 
-                return r;
-        }
+                hn = NULL;
+        } else
+                hn = b;
+
+        if (!hn) {
+                /* Don't override the hostname if it is unset and not
+                 * explicitly configured */
 
-        r = sethostname(hn, strlen(hn)) < 0 ? -errno : 0;
+                char *old_hostname = NULL;
 
-        if (r < 0)
-                log_warning("Failed to set hostname to <%s>: %s", hn, strerror(-r));
-        else
+                if ((old_hostname = gethostname_malloc())) {
+                        bool already_set;
+
+                        already_set = old_hostname[0] != 0;
+                        free(old_hostname);
+
+                        if (already_set)
+                                goto finish;
+                }
+
+                hn = "localhost";
+        }
+
+        if (sethostname(hn, strlen(hn)) < 0) {
+                log_warning("Failed to set hostname to <%s>: %m", hn);
+                r = -errno;
+        } else
                 log_info("Set hostname to <%s>.", hn);
 
-        free(hn);
+finish:
+        free(b);
 
         return r;
 }