From: Baptiste Daroussin <bapt@FreeBSD.org>
Date: Thu, 9 Nov 2023 10:20:41 +0000 (+0100)
Subject: write mail: fix regression regarding RFC 5321
X-Git-Tag: RELEASE_1_4_0rc3~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b502a85f5bc6f12c24950e20f424e4be2b831dec;p=thirdparty%2Fmlmmj.git

write mail: fix regression regarding RFC 5321

if a line on the email to write only contains a dot, then the
dot should be doubled otherwise the mail server will consider it
as the end of the DATA and will prematurely terminate the email.
---

diff --git a/src/mail-functions.c b/src/mail-functions.c
index 393885ce..d51dfa44 100644
--- a/src/mail-functions.c
+++ b/src/mail-functions.c
@@ -90,6 +90,12 @@ write_mailbody(int sockfd, FILE *fp, const char *tohdr)
 		}
 		next = fgetc(fp);
 		dprintf(sockfd, "\r\n");
+		if (next == '.') {
+			c = fgetc(fp);
+			if (c == EOF || c == '\n')
+				dprintf(sockfd, ".");
+			ungetc(c, fp);
+		}
 		if (addhdr && tohdr != NULL && next == '\n') {
 			dprintf(sockfd, "To: %s\r\n", tohdr);
 			addhdr = false;
diff --git a/tests/mlmmj.c b/tests/mlmmj.c
index bdc3b3e3..764f26f7 100644
--- a/tests/mlmmj.c
+++ b/tests/mlmmj.c
@@ -590,7 +590,7 @@ ATF_TC_BODY(write_mailbody, tc)
 		atf_tc_fail("Unexpected output (a single new line)");
 	}
 
-	/* With a single new line with a . */
+	/* With a single new line with a single . */
 	atf_utils_create_file("myemailbody.txt", "line\n.");
 	fp = fopen("myemailbody.txt", "r");
 	ATF_REQUIRE(fp != NULL);
@@ -598,7 +598,20 @@ ATF_TC_BODY(write_mailbody, tc)
 	write_mailbody(fd, fp,  "test@plop.meh");
 	close(fd);
 	fclose(fp);
-	if (!atf_utils_compare_file("out.txt", "line\r\n.")) {
+	if (!atf_utils_compare_file("out.txt", "line\r\n..")) {
+		atf_utils_cat_file("out.txt", ">");
+		atf_tc_fail("Unexpected output (single new line with a .)");
+	}
+
+	/* New line starting with a dot */
+	atf_utils_create_file("myemailbody.txt", "line\n.no");
+	fp = fopen("myemailbody.txt", "r");
+	ATF_REQUIRE(fp != NULL);
+	fd = open("out.txt", O_CREAT|O_TRUNC|O_WRONLY, 0644);
+	write_mailbody(fd, fp,  "test@plop.meh");
+	close(fd);
+	fclose(fp);
+	if (!atf_utils_compare_file("out.txt", "line\r\n.no")) {
 		atf_utils_cat_file("out.txt", ">");
 		atf_tc_fail("Unexpected output (single new line with a .)");
 	}