From: David Levine <levinedl@acm.org>
Date: Sat, 18 Aug 2012 00:31:22 +0000 (-0500)
Subject: Cleaned up message_id().
X-Git-Url: http://git.marmaro.de/?a=commitdiff_plain;h=4a47d073672a5d63e2d48acb498dafb6230acb52;p=mmh

Cleaned up message_id().
---

diff --git a/sbr/message_id.c b/sbr/message_id.c
index d1efd9d..bb71313 100644
--- a/sbr/message_id.c
+++ b/sbr/message_id.c
@@ -13,10 +13,10 @@
 #include <stdio.h>
 
 
-#define NMH_MESSAGE_ID_LOCALNAME 0
-#define NMH_MESSAGE_ID_RANDOM 1
-
-static int message_id_style = NMH_MESSAGE_ID_LOCALNAME;
+static enum {
+  NMH_MESSAGE_ID_LOCALNAME,
+  NMH_MESSAGE_ID_RANDOM
+} message_id_style = NMH_MESSAGE_ID_LOCALNAME;
 static char message_id_[BUFSIZ];
 
 
@@ -37,74 +37,75 @@ save_message_id_style (const char *value) {
 
 char *
 message_id (time_t tclock, int content_id) {
-  if (message_id_style == NMH_MESSAGE_ID_LOCALNAME) {
-    char *format = content_id  ?  "<%d.%ld.%%d@%s>"  :  "<%d.%ld@%s>";
-
-    snprintf (message_id_, sizeof message_id_, format,
-              (int) getpid (), (long) tclock, LocalName (1));
-  } else if  (message_id_style == NMH_MESSAGE_ID_RANDOM) {
-    char *format = content_id
-      ?  "<%d-%ld.%06ld%%d@%.*s.%.*s.%.*s>"
-      :  "<%d-%ld.%06ld@%.*s.%.*s.%.*s>";
-    /* Use a sequence of digits divisible by 3 because that will
-       expand to base64 without any waste.  Must be shorter than 58,
-       see below. */
-    unsigned char rnd[9];
-    /* The part after the '@' is divided into thirds.  The base64
-       encoded string will be 4/3 the size of rnd. */
-    size_t one_third = sizeof rnd * 4/3/3;
-
-    if (m_rand (rnd, sizeof rnd) == 0) {
-      struct timeval now;
-      /* All we really need is 4 * [sizeof rnd/3] + 2, as long as the
-         base64 encoding stays shorter than 76 bytes so embedded
-         newlines aren't necessary.  But use double the sizeof rnd
-         just to be safe. */
-      unsigned char rnd_base64[2 * sizeof rnd];
-      int i;
-
-      writeBase64 (rnd, sizeof rnd, rnd_base64);
-
-      for (i = strlen ((const char *) rnd_base64) - 1;
-           i > 0  &&  iscntrl (rnd_base64[i]);
-           --i) {
-        /* Remove trailing newline.  rnd_base64 had better be shorter
-           than 76 characters, so don't bother to look for embedded
-           newlines. */
-        rnd_base64[i] = '\0';
-      }
+  switch (message_id_style) {
+    case NMH_MESSAGE_ID_LOCALNAME: {
+      char *format = content_id  ?  "<%d.%ld.%%d@%s>"  :  "<%d.%ld@%s>";
+
+      snprintf (message_id_, sizeof message_id_, format,
+                (int) getpid (), (long) tclock, LocalName (1));
+
+      break;
+    }
+
+    case NMH_MESSAGE_ID_RANDOM: {
+      char *format = content_id
+        ?  "<%d-%ld.%06ld%%d@%.*s.%.*s.%.*s>"
+        :  "<%d-%ld.%06ld@%.*s.%.*s.%.*s>";
+      /* Use a sequence of digits divisible by 3 because that will
+         expand to base64 without any waste.  Must be shorter than 58,
+         see below. */
+      unsigned char rnd[9];
+      /* The part after the '@' is divided into thirds.  The base64
+         encoded string will be 4/3 the size of rnd. */
+      size_t one_third = sizeof rnd * 4/3/3;
+
+      if (m_rand (rnd, sizeof rnd) == 0) {
+        struct timeval now;
+        /* All we really need is 4 * [sizeof rnd/3] + 2, as long as
+           the base64 encoding stays shorter than 76 bytes so embedded
+           newlines aren't necessary.  But use double the sizeof rnd
+           just to be safe. */
+        unsigned char rnd_base64[2 * sizeof rnd];
+        unsigned char *cp;
+        int i;
+
+        writeBase64 (rnd, sizeof rnd, rnd_base64);
+
+        for (i = strlen ((const char *) rnd_base64) - 1;
+             i > 0  &&  iscntrl (rnd_base64[i]);
+             --i) {
+          /* Remove trailing newline.  rnd_base64 had better be
+             shorter than 76 characters, so don't bother to look for
+             embedded newlines. */
+          rnd_base64[i] = '\0';
+        }
 
-      {
-        char *cp;
         /* Try to make the base64 string look a little more like a
-           hostname by replacing + with - and / with _.  Also, the
-           format string inserts a couple of dots. */
-        for (cp = (char *) rnd_base64; *cp; ++cp) {
-          char *plus, *slash;
-          if ((plus = strchr (cp, '+'))) {
-            *plus = '-';
-          } else if ((slash = strchr (cp, '/'))) {
-            *slash = '_';
-          } else {
-            break;
+           hostname by replacing + with - and / with _. */
+        for (cp = rnd_base64; *cp; ++cp) {
+          if (*cp == '+') {
+            *cp = '-';
+          } else if (*cp == '/') {
+            *cp = '_';
           }
         }
-      }
 
-      /* gettimeofday() and getpid() shouldn't fail on POSIX platforms. */
-      gettimeofday (&now, 0);
+        /* gettimeofday() and getpid() shouldn't fail on POSIX platforms. */
+        gettimeofday (&now, 0);
+
+        /* The format string inserts a couple of dots, for the benefit
+           of spam filters that want to see a message id with a final
+           part that resembles a hostname. */
+        snprintf (message_id_, sizeof message_id_, format,
+                  getpid (), (long) now.tv_sec, (long) now.tv_usec,
+                  one_third, rnd_base64,
+                  one_third, &rnd_base64[one_third],
+                  one_third, &rnd_base64[2*one_third]);
+      }
 
-      snprintf (message_id_, sizeof message_id_, format,
-                getpid (), (long) now.tv_sec, (long) now.tv_usec,
-                one_third, rnd_base64,
-                one_third, &rnd_base64[one_third],
-                one_third, &rnd_base64[2*one_third]);
+      break;
     }
-  } else {
-    /* Should never get here. */
-    adios (0, "invalid message id style \"%s\"", message_id_style);
   }
 
-
   return message_id_;
 }