Add support to read /etc/os-release for system information.

/etc/os-release is introduced with systemd which will be in all the
major distributions, soon. For backwards-compatibility, the lsb_release
method is still there and will be used if no /etc/os-release is available.

diff --git a/src/lldpd.c b/src/lldpd.c
index b19af11252d174ca7b7c7a50a1618dfe5c13a534..1641f13da588f16dbb6284d1b0b0cc35ec159ea2 100644 (file)
--- a/src/lldpd.c
+++ b/src/lldpd.c
@@ -89,6 +89,7 @@ static void            lldpd_decode(struct lldpd *, char *, int,
 static void             lldpd_update_chassis(struct lldpd_chassis *,
                            const struct lldpd_chassis *);
 static char            *lldpd_get_lsb_release(void);
+static char            *lldpd_get_os_release(void);
 #ifdef ENABLE_LLDPMED
 static void             lldpd_med(struct lldpd_chassis *);
 #endif
@@ -553,6 +554,46 @@ lldpd_get_lsb_release() {
        return NULL;
 }
 
+/* Same like lldpd_get_lsb_release but reads /etc/os-release for PRETTY_NAME=. */
+static char *
+lldpd_get_os_release() {
+       static char release[1024];
+
+       FILE *fp = fopen("/etc/os-release", "r");
+       if (!fp) {
+               LLOG_WARN("Could not open /etc/os-release to read system information");
+               return NULL;
+       }
+
+       char line[1024];
+       char *key, *val;
+
+       while ((fgets(line, 1024, fp) != NULL)) {
+               key = strtok(line, "=");
+               val = strtok(NULL, "=");
+
+               if (strncmp(key, "PRETTY_NAME", 1024) == 0) {
+                       strncpy(release, val, 1024);
+                       break;
+               }
+       }
+       fclose(fp);
+
+       /* Remove trailing newline and all " in the string. */
+       char *ptr1 = release;
+       char *ptr2 = release;
+       while (*ptr1 != 0) {
+               if ((*ptr1 == '"') || (*ptr1 == '\n')) {
+                       ++ptr1;
+               } else {
+                       *ptr2++ = *ptr1++;
+               }
+       }
+       *ptr2 = 0;
+
+       return release;
+}
+
 int
 lldpd_callback_add(struct lldpd *cfg, int fd, void(*fn)(CALLBACK_SIG), void *data)
 {
@@ -889,7 +930,7 @@ lldpd_update_localchassis(struct lldpd *cfg)
                        fatal("failed to set full system description");
         } else {
                if (cfg->g_advertise_version) {
-                       if (asprintf(&LOCAL_CHASSIS(cfg)->c_descr, "%s%s %s %s",
+                       if (asprintf(&LOCAL_CHASSIS(cfg)->c_descr, "%s %s %s %s",
                                cfg->g_lsb_release?cfg->g_lsb_release:"",
                                un.sysname, un.release, un.machine)
                                 == -1)
@@ -1189,7 +1230,12 @@ lldpd_main(int argc, char *argv[])
                close(pid);
        }
 
-       lsb_release = lldpd_get_lsb_release();
+       /* Try to read system information from /etc/os-release if possible.
+          Fall back to lsb_release for compatibility. */
+       lsb_release = lldpd_get_os_release();
+       if (!lsb_release) {
+               lsb_release = lldpd_get_lsb_release();
+       }
 
        priv_init(PRIVSEP_CHROOT);