From af80a74d65f30cc89d03f9d8db6787c21d996210 Mon Sep 17 00:00:00 2001
From: Simon Schubert <corecode@dragonflybsd.org>
Date: Thu, 16 Jul 2009 16:04:25 +0200
Subject: [PATCH] dma: add required headers if they are not present

RFC2822 states that we must or should include the Date, Message-Id, and
From headers, so add them if they are not present in the message.
---
 libexec/dma/dma.c | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/libexec/dma/dma.c b/libexec/dma/dma.c
index f3a6e7cb44..ee48658179 100644
--- a/libexec/dma/dma.c
+++ b/libexec/dma/dma.c
@@ -422,12 +422,22 @@ rfc822date(void)
 	return (str);
 }
 
+static int
+strprefixcmp(const char *str, const char *prefix)
+{
+	return (strncasecmp(str, prefix, strlen(prefix)));
+}
+
 static int
 readmail(struct queue *queue, const char *sender, int nodot)
 {
 	char line[1000];	/* by RFC2822 */
 	size_t linelen;
 	int error;
+	int had_headers = 0;
+	int had_from = 0;
+	int had_messagid = 0;
+	int had_date = 0;
 
 	error = snprintf(line, sizeof(line),
 		"Received: from %s (uid %d)\n"
@@ -453,6 +463,34 @@ readmail(struct queue *queue, const char *sender, int nodot)
 			errno = EINVAL;		/* XXX mark permanent errors */
 			return (-1);
 		}
+		if (!had_headers) {
+			if (strprefixcmp(line, "Date:") == 0)
+				had_date = 1;
+			else if (strprefixcmp(line, "Message-Id:") == 0)
+				had_messagid = 1;
+			else if (strprefixcmp(line, "From:") == 0)
+				had_from = 1;
+		}
+		if (strcmp(line, "\n") == 0 && !had_headers) {
+			had_headers = 1;
+			while (!had_date || !had_messagid || !had_from) {
+				if (!had_date) {
+					had_date = 1;
+					snprintf(line, sizeof(line), "Date: %s\n", rfc822date());
+				} else if (!had_messagid) {
+					/* XXX better msgid, assign earlier and log? */
+					had_messagid = 1;
+					snprintf(line, sizeof(line), "Message-Id: <%"PRIxMAX"@%s>\n",
+						 queue->id, hostname());
+				} else if (!had_from) {
+					had_from = 1;
+					snprintf(line, sizeof(line), "From: <%s>\n", sender);
+				}
+				if ((size_t)write(queue->mailfd, line, strlen(line)) != strlen(line))
+					return (-1);
+			}
+			strcpy(line, "\n");
+		}
 		if (!nodot && linelen == 2 && line[0] == '.')
 			break;
 		if ((size_t)write(queue->mailfd, line, linelen) != linelen)
-- 
2.41.0