test: Add test that emacs interface actually sends mail.

Rather than *reall* sending mail here, we instead have a new test
program, smtp-dummy which implements (a small piece of) the
server-side SMTP protocol and saves a mail message to the filename
provided. This gives us reasonable test coverage of a large chunk of
the notmuch+emacs code base (down to talking to an SMTP server with
the final mail contents).

1 files changed, 206 insertions, 0 deletions

diff --git a/test/smtp-dummy.c b/test/smtp-dummy.c
new file mode 100644
index 00000000..e58d0ad6
--- /dev/null
+++ b/test/smtp-dummy.c
@@ -0,0 +1,206 @@
+/* smtp-dummy - Dummy SMTP server that delivers mail to the given file
+ *
+ * Copyright © 2010 Carl Worth
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see http://www.gnu.org/licenses/ .
+ *
+ * Authors: Carl Worth <cworth@cworth.org>
+ */
+
+/* This (non-compliant) SMTP server listens on localhost, port 25025
+ * and delivers a mail received to the given filename, (specified as a
+ * command-line argument). It exists after the first client connection
+ * completes.
+ *
+ * It implements very little of the SMTP protocol, even less than
+ * specified as the minimum implementation in the SMTP RFC, (not
+ * implementing RSET, NOOP, nor VRFY). And it doesn't do any
+ * error-checking on the input.
+ *
+ * That is to say, if you use this program, you will very likely find
+ * cases where it doesn't do everything your SMTP client expects. You
+ * have been warned.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <netinet/ip.h>
+#include <netdb.h>
+#include <unistd.h>
+
+#define STRNCMP_LITERAL(var, literal) \
+    strncmp ((var), (literal), sizeof (literal) - 1)
+
+static void
+receive_data_to_file (FILE *peer, FILE *output)
+{
+	char *line = NULL;
+	size_t line_size;
+	ssize_t line_len;
+
+	while ((line_len = getline (&line, &line_size, peer)) != -1) {
+		if (STRNCMP_LITERAL (line, ".\r\n") == 0)
+			break;
+		if (line_len < 2)
+			continue;
+		if (line[line_len-1] == '\n' && line[line_len-2] == '\r') {
+			line[line_len-2] = '\n';
+			line[line_len-1] = '\0';
+		}
+		fprintf (output, "%s",
+			 line[0] == '.' ? line + 1 : line);
+	}
+
+	free (line);
+}
+
+static int
+process_command (FILE *peer, FILE *output, const char *command)
+{
+	if (STRNCMP_LITERAL (command, "EHLO ") == 0) {
+		fprintf (peer, "502\r\n");
+		fflush (peer);
+	} else if (STRNCMP_LITERAL (command, "HELO ") == 0) {
+		fprintf (peer, "250 localhost\r\n");
+		fflush (peer);
+	} else if (STRNCMP_LITERAL (command, "MAIL FROM:") == 0 ||
+		   STRNCMP_LITERAL (command, "RCPT TO:") == 0) {
+		fprintf (peer, "250 OK\r\n");
+		fflush (peer);
+	} else if (STRNCMP_LITERAL (command, "DATA") == 0) {
+		fprintf (peer, "354 End data with <CR><LF>.<CR><LF>\r\n");
+		fflush (peer);
+		receive_data_to_file (peer, output);
+		fprintf (peer, "250 OK\r\n");
+		fflush (peer);
+	} else if (STRNCMP_LITERAL (command, "QUIT") == 0) {
+		fprintf (peer, "221 BYE\r\n");
+		fflush (peer);
+		return 1;
+	} else {
+		fprintf (stderr, "Unknown command: %s\n", command);
+	}
+	return 0;
+}
+
+static void
+do_smtp_to_file (FILE *peer, FILE *output)
+{
+	char buf[4096];
+	ssize_t bytes;
+	char greeting[] = "220 localhost smtp-dummy\r\n";
+	char *line = NULL;
+	size_t line_size;
+	ssize_t line_len;
+
+	fprintf (peer, "220 localhost smtp-dummy\r\n");
+	fflush (peer);
+
+	while ((line_len = getline (&line, &line_size, peer)) != -1) {
+		if (process_command (peer, output, line))
+			break;
+	}
+
+	free (line);
+}
+
+int
+main (int argc, char *argv[])
+{
+	char *output_filename;
+	FILE *peer_file, *output;
+	int sock, peer, err;
+	struct sockaddr_in addr, peer_addr;
+	struct hostent *hostinfo;
+	socklen_t peer_addr_len;
+	int reuse;
+
+	if (argc != 2) {
+		fprintf (stderr, "Usage: %s <output-file>\n", argv[0]);
+		exit (1);
+	}
+
+	output_filename = argv[1];
+	output = fopen (output_filename, "w");
+	if (output == NULL) {
+		fprintf (stderr, "Failed to open %s for writing: %s\n",
+			 output_filename, strerror (errno));
+		exit (1);
+	}
+
+	sock = socket (AF_INET, SOCK_STREAM, 0);
+	if (sock == -1) {
+		fprintf (stderr, "Error: socket() failed: %s\n",
+			 strerror (errno));
+		exit (1);
+	}
+
+	reuse = 1;
+	err = setsockopt (sock, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof (reuse));
+	if (err) {
+		fprintf (stderr, "Error: setsockopt() failed: %s\n",
+			 strerror (errno));
+		exit (1);
+	}
+
+	hostinfo = gethostbyname ("localhost");
+	if (hostinfo == NULL) {
+		fprintf (stderr, "Unknown host: localhost\n");
+		exit (1);
+	}
+
+	addr.sin_family = AF_INET;
+	addr.sin_port = htons (25025);
+	addr.sin_addr = *(struct in_addr *) hostinfo->h_addr;
+	err = bind (sock, (struct sockaddr *) &addr, sizeof(addr));
+	if (err) {
+		fprintf (stderr, "Error: bind() failed: %s\n",
+			 strerror (errno));
+		close (sock);
+		exit (1);
+	}
+
+	err = listen (sock, 1);
+	if (err) {
+		fprintf (stderr, "Error: listen() failed: %s\n",
+			 strerror (errno));
+		close (sock);
+		exit (1);
+	}
+
+	peer_addr_len = sizeof (peer_addr);
+	peer = accept (sock, (struct sockaddr *) &peer_addr, &peer_addr_len);
+	if (peer == -1) {
+		fprintf (stderr, "Error: accept() failed: %s\n",
+			 strerror (errno));
+		exit (1);
+	}
+
+	peer_file = fdopen (peer, "w+");
+	if (peer_file == NULL) {
+		fprintf (stderr, "Error: fdopen() failed: %s\n",
+			 strerror (errno));
+		return;
+	}
+
+	do_smtp_to_file (peer_file, output);
+
+	fclose (output);
+	fclose (peer_file);
+	close (sock);
+
+	return 0;
+}