From 2867d16bc9bae9764904efbf44cd5131fca1bc9b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Fonseca?= <jrfonseca@users.sourceforge.net>
Date: Thu, 3 Jul 2003 17:37:11 +0000
Subject: Modularization of the code. Hability to get the recipients from the
 message headers. Local delivery via a MDA.

---
 rfc822.c | 193 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 193 insertions(+)
 create mode 100644 rfc822.c

(limited to 'rfc822.c')

diff --git a/rfc822.c b/rfc822.c
new file mode 100644
index 0000000..5f1cac8
--- /dev/null
+++ b/rfc822.c
@@ -0,0 +1,193 @@
+/**
+ * \file rfc822.c
+ * Code for slicing and dicing RFC822 mail headers.
+ * 
+ *  How to parse RFC822 headers in C. This is not a fully conformant
+ *  implementation of RFC822 or RFC2822, but it has been in production use in a
+ *  widely-deployed MTA (fetcmail) since 1996 without complaints.  Really
+ *  perverse combinations of quoting and commenting could break it.
+ * 
+ * \author Eric S. Raymond <esr@thyrsus.com>, 1997.  This source code example
+ * is part of fetchmail and the Unix Cookbook, and are released under the MIT
+ * license. 
+ */
+
+
+#include <stdio.h>
+#include <ctype.h>
+#include <string.h>
+#include <stdlib.h>
+
+
+#ifndef TRUE
+#define TRUE 1
+#define FALSE 0
+#endif
+
+#define HEADER_END(p)	((p)[0] == '\n' && ((p)[1] != ' ' && (p)[1] != '\t'))
+
+
+/**
+ * Parse addresses in succession out of a specified RFC822 header.
+ *
+ * \param hdr header to be parsed, NUL to continue previous \p hdr. 
+ */
+char *next_address(const char *hdr)
+{
+    static unsigned char address[BUFSIZ];
+    static int tp;
+    static const unsigned char *hp;
+    static int	state, oldstate;
+    int parendepth = 0;
+
+#define START_HDR	0	/* before header colon */
+#define SKIP_JUNK	1	/* skip whitespace, \n, and junk */
+#define BARE_ADDRESS	2	/* collecting address without delimiters */
+#define INSIDE_DQUOTE	3	/* inside double quotes */
+#define INSIDE_PARENS	4	/* inside parentheses */
+#define INSIDE_BRACKETS	5	/* inside bracketed address */
+#define ENDIT_ALL	6	/* after last address */
+
+#define NEXTTP()	((tp < sizeof(address)-1) ? tp++ : tp)
+
+    if (hdr)
+    {
+	hp = hdr;
+	state = START_HDR;
+	tp = 0;
+    }
+
+    for (; *hp; hp++)
+    {
+
+	if (state == ENDIT_ALL)		/* after last address */
+	    return(NULL);
+	else if (HEADER_END(hp))
+	{
+	    state = ENDIT_ALL;
+	    if (tp)
+	    {
+		while (isspace(address[--tp]))
+		    continue;
+		address[++tp] = '\0';
+		tp = 0;
+		return (address);
+	    }
+	    return((unsigned char *)NULL);
+	}
+	else if (*hp == '\\')		/* handle RFC822 escaping */
+	{
+	    if (state != INSIDE_PARENS)
+	    {
+		address[NEXTTP()] = *hp++;	/* take the escape */
+		address[NEXTTP()] = *hp;	/* take following unsigned char */
+	    }
+	}
+	else switch (state)
+	{
+	case START_HDR:   /* before header colon */
+	    if (*hp == ':')
+		state = SKIP_JUNK;
+	    break;
+
+	case SKIP_JUNK:		/* looking for address start */
+	    if (*hp == '"')	/* quoted string */
+	    {
+		oldstate = SKIP_JUNK;
+	        state = INSIDE_DQUOTE;
+		address[NEXTTP()] = *hp;
+	    }
+	    else if (*hp == '(')	/* address comment -- ignore */
+	    {
+		parendepth = 1;
+		oldstate = SKIP_JUNK;
+		state = INSIDE_PARENS;    
+	    }
+	    else if (*hp == '<')	/* begin <address> */
+	    {
+		state = INSIDE_BRACKETS;
+		tp = 0;
+	    }
+	    else if (*hp != ',' && !isspace(*hp))
+	    {
+		--hp;
+	        state = BARE_ADDRESS;
+	    }
+	    break;
+
+	case BARE_ADDRESS:   	/* collecting address without delimiters */
+	    if (*hp == ',')  	/* end of address */
+	    {
+		if (tp)
+		{
+		    address[NEXTTP()] = '\0';
+		    state = SKIP_JUNK;
+		    tp = 0;
+		    return(address);
+		}
+	    }
+	    else if (*hp == '(')  	/* beginning of comment */
+	    {
+		parendepth = 1;
+		oldstate = BARE_ADDRESS;
+		state = INSIDE_PARENS;    
+	    }
+	    else if (*hp == '<')  	/* beginning of real address */
+	    {
+		state = INSIDE_BRACKETS;
+		tp = 0;
+	    }
+	    else if (*hp == '"')        /* quoted word, copy verbatim */
+	    {
+	        oldstate = state;
+		state = INSIDE_DQUOTE;
+                address[NEXTTP()] = *hp;
+            }
+	    else if (!isspace(*hp)) 	/* just take it, ignoring whitespace */
+		address[NEXTTP()] = *hp;
+	    break;
+
+	case INSIDE_DQUOTE:	/* we're in a quoted string, copy verbatim */
+	    if (*hp != '"')
+	        address[NEXTTP()] = *hp;
+	    else
+	    {
+	        address[NEXTTP()] = *hp;
+		state = oldstate;
+	    }
+	    break;
+
+	case INSIDE_PARENS:	/* we're in a parenthesized comment, ignore */
+	    if (*hp == '(')
+		++parendepth;
+	    else if (*hp == ')')
+		--parendepth;
+	    if (parendepth == 0)
+		state = oldstate;
+	    break;
+
+	case INSIDE_BRACKETS:	/* possible <>-enclosed address */
+	    if (*hp == '>')	/* end of address */
+	    {
+		address[NEXTTP()] = '\0';
+		state = SKIP_JUNK;
+		++hp;
+		tp = 0;
+		return(address);
+	    }
+	    else if (*hp == '<')	/* nested <> */
+	        tp = 0;
+	    else if (*hp == '"')	/* quoted address */
+	    {
+	        address[NEXTTP()] = *hp;
+		oldstate = INSIDE_BRACKETS;
+		state = INSIDE_DQUOTE;
+	    }
+	    else			/* just copy address */
+		address[NEXTTP()] = *hp;
+	    break;
+	}
+    }
+
+    return(NULL);
+}
-- 
cgit v1.2.3