* Added an API function to extract and unfold specific RFC822 fields.

[citadel.git] / citadel / internet_addressing.c

diff --git a/citadel/internet_addressing.c b/citadel/internet_addressing.c
index 3ec2d6a6c55c64fbe9926b6f2a402c6705055a8c..00fde5ca64b38fb5e3d86e7760a47e908ebf1da8 100644 (file)
--- a/citadel/internet_addressing.c
+++ b/citadel/internet_addressing.c
@@ -558,3 +558,70 @@ struct CtdlMessage *convert_internet_message(char *rfc822) {
        return msg;
 }
 
+
+
+/*
+ * Look for a particular header field in an RFC822 message text.  If the
+ * requested field is found, it is unfolded (if necessary) and returned to
+ * the caller.  The field name is stripped out, leaving only its contents.
+ * The caller is responsible for freeing the returned buffer.  If the requested
+ * field is not present, or anything else goes wrong, it returns NULL.
+ */
+char *rfc822_fetch_field(char *rfc822, char *fieldname) {
+       int pos = 0;
+       int beg, end;
+       int done = 0;
+       int colonpos, i;
+       char *fieldbuf = NULL;
+
+       /* Should never happen, but sometimes we get stupid */
+       if (rfc822 == NULL) return(NULL);
+       if (fieldname == NULL) return(NULL);
+
+       while (!done) {
+
+               /* Locate beginning and end of field, keeping in mind that
+                * some fields might be multiline
+                */
+               beg = pos;
+               end = (-1);
+               for (pos=beg; ((pos<=strlen(rfc822))&&(end<0)); ++pos) {
+                       if ((rfc822[pos]=='\n')
+                          && (!isspace(rfc822[pos+1]))) {
+                               end = pos;
+                       }
+                       if ( (rfc822[pos]=='\n')        /* done w. headers? */
+                          && ( (rfc822[pos+1]=='\n')
+                             ||(rfc822[pos+1]=='\r'))) {
+                               end = pos;
+                               done = 1;
+                       }
+
+               }
+
+               /* At this point we have a field.  Is it The One? */
+               if (end > beg) {
+                       fieldbuf = mallok((end-beg)+3);
+                       if (fieldbuf == NULL) return(NULL);
+                       safestrncpy(fieldbuf, &rfc822[beg], (end-beg)+1);
+                       unfold_rfc822_field(fieldbuf);
+                       colonpos = (-1);
+                       for (i = strlen(fieldbuf); i >= 0; --i) {
+                               if (fieldbuf[i] == ':') colonpos = i;
+                       }
+                       if (colonpos > 0) {
+                               fieldbuf[colonpos] = 0;
+                               if (!strcasecmp(fieldbuf, fieldname)) {
+                                       strcpy(fieldbuf, &fieldbuf[colonpos+1]);
+                                       striplt(fieldbuf);
+                                       return(fieldbuf);
+                               }
+                       }
+                       phree(fieldbuf);
+               }
+
+               /* If we've hit the end of the message, bail out */
+               if (pos > strlen(rfc822)) done = 1;
+       }
+       return(NULL);
+}