Fix registration of really large records, like it is necessary for XEP-0174 (jabber...

[catta] / avahi-core / domain-util.c

diff --git a/avahi-core/domain-util.c b/avahi-core/domain-util.c
index d4cc2ad91f02782e7ef07ce181fedf05175c4faf..777a064d009372a04f59ebfbc6c0ff280e75d85f 100644 (file)
--- a/avahi-core/domain-util.c
+++ b/avahi-core/domain-util.c
@@ -27,25 +27,114 @@
 #include <assert.h>
 #include <string.h>
 #include <unistd.h>
+#include <ctype.h>
+#include <sys/utsname.h>
+#include <stdio.h>
 
 #include <avahi-common/malloc.h>
 
+#include "log.h"
 #include "domain-util.h"
+#include "util.h"
 
-char *avahi_get_host_name(char *ret_s, size_t size) {
-#ifdef HOST_NAME_MAX
-    char t[HOST_NAME_MAX];
-#else
-    char t[256];
-#endif
+static void strip_bad_chars(char *s) {
+    char *p, *d;
+
+    s[strcspn(s, ".")] = 0;
+    
+    for (p = s, d = s; *p; p++) 
+        if ((*p >= 'a' && *p <= 'z') ||
+            (*p >= 'A' && *p <= 'Z') ||
+            (*p >= '0' && *p <= '9') ||
+            *p == '-')
+            *(d++) = *p;
+
+    *d = 0;
+}
+
+#ifdef __linux__
+static int load_lsb_distrib_id(char *ret_s, size_t size) {
+    FILE *f;
     
     assert(ret_s);
     assert(size > 0);
+
+    if (!(f = fopen("/etc/lsb-release", "r")))
+        return -1;
+
+    while (!feof(f)) {
+        char ln[256], *p;
+
+        if (!fgets(ln, sizeof(ln), f))
+            break;
+
+        if (strncmp(ln, "DISTRIB_ID=", 11))
+            continue;
+
+        p = ln + 11;
+        p += strspn(p, "\"");
+        p[strcspn(p, "\"")] = 0;
+
+        snprintf(ret_s, size, "%s", p);
+
+        fclose(f);
+        return 0;
+    }
+
+    fclose(f);
+    return -1;
+}
+#endif
+
+char *avahi_get_host_name(char *ret_s, size_t size) {
+    assert(ret_s);
+    assert(size > 0);
+
+    if (gethostname(ret_s, size) >= 0) {
+        ret_s[size-1] = 0;
+        strip_bad_chars(ret_s);
+    } else
+        *ret_s = 0;
+
+    if (strcmp(ret_s, "localhost") == 0 || strncmp(ret_s, "localhost.", 10) == 0) {
+        *ret_s = 0;
+        avahi_log_warn("System host name is set to 'localhost'. This is not a suitable mDNS host name, looking for alternatives.");
+    }
     
-    gethostname(t, sizeof(t));
-    t[sizeof(t)-1] = 0;
+    if (*ret_s == 0) {
+        /* No hostname was set, so let's take the OS name */
+
+#ifdef __linux__
+
+        /* Try LSB distribution name first */
+        if (load_lsb_distrib_id(ret_s, size) >= 0) {
+            strip_bad_chars(ret_s);
+            avahi_strdown(ret_s);
+        }
+
+        if (*ret_s == 0)
+#endif
+
+        {
+            /* Try uname() second */
+            struct utsname utsname;
+            
+            if (uname(&utsname) >= 0) {
+                snprintf(ret_s, size, "%s", utsname.sysname);
+                strip_bad_chars(ret_s);
+                avahi_strdown(ret_s);
+            }
+
+            /* Give up */
+            if (*ret_s == 0)
+                snprintf(ret_s, size, "unnamed");
+        }
+    }
+
+    if (size >= AVAHI_LABEL_MAX)
+       ret_s[AVAHI_LABEL_MAX-1] = 0;    
     
-    return avahi_normalize_name(t, ret_s, size);
+    return ret_s;
 }
 
 char *avahi_get_host_name_strdup(void) {