various improvements

- use dig for resolving host names
- ascon.c: fix terminator parsing
- property callback: change property before callback
- logger.c:default for logger period must be the old value instead of 1
- add frappy type history writing
- increase max. logreader line length
- HIPNONE returns "null" with json protocol
- encode strings properly in formatNameValue
- fix memory leak in json2tcl
- scriptcontext: do not show debug messages when script starts with underscore or when the "send" property is empty
- scriptcontext: remove args for action timestamp
- scriptcontext: "que" function will replace an already queued action, e.g. for 'halt
- introduced updatestatus script

socketaddr.c

@@ -0,0 +1,72 @@
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netdb.h>
+#include <arpa/inet.h>
+#include <string.h>
+#include <stdio.h>
+
+int MakeSocketAddr(
+    struct sockaddr *sockaddrPtr,  /* socket address */
+    char *hostname,       /* name or ip of host. NULL implies INADDR_ANY */
+    int port,             /* port number */
+    char dotted_ip[16]) { /* resolved ip addr */
+  /*
+    Workaround for cases, where the local cache is not updated (yet)
+    often, gethostbyname gets a cached value, but dig will get a fresh one
+    note after an internet research: dig is recommended over nslookup
+  */
+
+  struct hostent *hostent;      /* Host database entry */
+  struct sockaddr_in *sadr = (struct sockaddr_in *)sockaddrPtr;
+  FILE *fil;
+  char line[256];
+  int l;
+
+  (void) memset(sadr, 0, sizeof(*sadr));
+  if (dotted_ip) { /* default value: failure */
+    dotted_ip[0] = 0;
+  }
+  sadr->sin_family = AF_INET;
+  sadr->sin_port = htons((unsigned short)port);
+  if (hostname == NULL) {
+    /* do not need to copy, as INADDR_ANY is all zero bytes */
+    return 1;
+  }
+  if (inet_pton(AF_INET, hostname, &sadr->sin_addr) == 1) {
+    /* resolved as dotted numbers notation */
+    return 1;
+  }
+  hostent = gethostbyname(hostname);
+  if (hostent == 0) {
+    /* we assume that when gethostname gets no entry, dig will also fail.
+    That way, dig will not be called repeatedly for no reason */
+    return 0;
+  }
+  /* copy the address: in case dig fails, we use the cached value */
+  memcpy(&sadr->sin_addr, hostent->h_addr_list[0], 4);
+  /* we use hostent->h_name instead of hostname here, as this has already
+     the proper domain added */
+  snprintf(line, sizeof line, "timeout 1 dig +short %s", hostent->h_name);
+  fil = popen(line, "r");
+  if (fil != NULL) {
+    if (fgets(line, sizeof(line), fil) != NULL) {
+      l = strlen(line);
+      if (line[l-1] <= ' ') line[l-1] = 0; /* strip off newline */
+      /* silently ignore return value, if it fails, we take the cached value */
+      inet_pton(AF_INET, line, &sadr->sin_addr);
+    }
+    fclose(fil);
+  }
+  if (dotted_ip) {
+    inet_ntop(AF_INET, &sadr->sin_addr, dotted_ip, 16);
+  }
+  return 1;
+}
+
+int CreateSocketAdress(struct sockaddr_in *sockaddrPtr,  /* Socket address */
+                       char *host,       /* Host.  NULL implies INADDR_ANY */
+                       int port)
+{
+   return MakeSocketAddr((struct sockaddr *)sockaddrPtr, host, port, NULL);
+}