add experimental crm114 backend

1 files changed, 200 insertions, 0 deletions

diff --git a/crm114-exec.c b/crm114-exec.c
new file mode 100644
index 0000000..91a72e7
--- /dev/null
+++ b/crm114-exec.c
@@ -0,0 +1,200 @@
+/*
+ * crm114 backend for dovecot antispam plugin
+ *
+ * Copyright (C) 2004-2007  Johannes Berg <johannes@sipsolutions.net>
+ *                    2006  Frank Cusack
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License Version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <sys/wait.h>
+#include <fcntl.h>
+
+#include "lib.h"
+#include "mail-storage-private.h"
+
+#include "antispam-plugin.h"
+#include "signature.h"
+
+static const char *reaver_binary = "/bin/false";
+static char **extra_args = NULL;
+static int extra_args_num = 0;
+
+#define FIXED_ARGS_NUM 2
+#define CRM_HDR "X-CRM114-CacheID"
+
+static int call_reaver(const char *signature, enum classification wanted)
+{
+	pid_t pid;
+	const char *class_arg;
+	int pipes[2];
+
+	switch (wanted) {
+	case CLASS_NOTSPAM:
+		class_arg = "good";
+		break;
+	case CLASS_SPAM:
+		class_arg = "spam";
+		break;
+	}
+
+	/*
+	 * For reaver stdin, it wants to read a full message but
+	 * really only needs the signature.
+	 */
+	pipe(pipes);
+
+	pid = fork();
+	if (pid < 0)
+		return -1;
+
+	if (pid) {
+		int status;
+
+		close(pipes[0]);
+
+		/*
+		 * Reaver wants the mail but only needs the cache ID
+		 */
+		write(pipes[1], CRM_HDR, strlen(CRM_HDR));
+		write(pipes[1], ": ", 2);
+		write(pipes[1], signature, strlen(signature));
+		write(pipes[1], "\r\n\r\n", 4);
+		close(pipes[1]);
+
+		/*
+		 * Wait for reaver
+		 */
+		waitpid(pid, &status, 0);
+		if (!WIFEXITED(status))
+			return 1;
+
+		return WEXITSTATUS(status);
+	} else {
+		int fd = open("/dev/null", O_RDONLY);
+		char **argv;
+		int sz = sizeof(char *) * (FIXED_ARGS_NUM + extra_args_num + 1);
+		int i;
+
+		argv = i_malloc(sz);
+		memset(argv, 0, sz);
+
+		close(0);
+		close(1);
+		close(2);
+		/* see above */
+		close(pipes[1]);
+
+		if (dup2(pipes[0], 0) != 2)
+			exit(1);
+		close(pipes[0]);
+
+		if (dup2(fd, 1) != 0)
+			exit(1);
+		if (dup2(fd, 2) != 0)
+			exit(1);
+		close(fd);
+
+		argv[0] = (char *)reaver_binary;
+		argv[1] = (char *)class_arg;
+
+		debug("antispam: %s %s ...", reaver_binary, class_arg);
+
+		for (i = 0; i < extra_args_num; i++)
+			argv[i + FIXED_ARGS_NUM] = (char *)extra_args[i];
+
+		execv(reaver_binary, argv);
+		/* fall through if reaver can't be found */
+		exit(127);
+		/* not reached */
+		return -1;
+	}
+}
+
+struct antispam_transaction_context {
+	struct siglist *siglist;
+};
+
+struct antispam_transaction_context *backend_start(struct mailbox *box)
+{
+	struct antispam_transaction_context *ast;
+
+	ast = i_new(struct antispam_transaction_context, 1);
+	ast->siglist = NULL;
+	return ast;
+}
+
+void backend_rollback(struct antispam_transaction_context *ast)
+{
+	signature_list_free(&ast->siglist);
+	i_free(ast);
+}
+
+int backend_commit(struct mailbox_transaction_context *ctx,
+		   struct antispam_transaction_context *ast)
+{
+	struct siglist *item = ast->siglist;
+	int ret = 0;
+
+	while (item) {
+		if (call_reaver(item->sig, item->wanted)) {
+			ret = -1;
+			mail_storage_set_error(ctx->box->storage,
+					       "Failed to call reaver");
+			break;
+		}
+		item = item->next;
+	}
+
+	signature_list_free(&ast->siglist);
+	i_free(ast);
+	return ret;
+}
+
+int backend_handle_mail(struct mailbox_transaction_context *t,
+			struct antispam_transaction_context *ast,
+			struct mail *mail, enum classification want)
+{
+	return signature_extract_to_list(t, mail, &ast->siglist, want);
+}
+
+void backend_init(pool_t pool)
+{
+	char *tmp;
+	int i;
+
+	tmp = getenv("ANTISPAM_CRM_BINARY");
+	if (tmp) {
+		reaver_binary = tmp;
+		debug("antispam: reaver binary set to %s\n", tmp);
+	}
+
+	tmp = getenv("ANTISPAM_CRM_ARGS");
+	if (tmp) {
+		extra_args = p_strsplit(pool, tmp, ";");
+		extra_args_num = str_array_length(
+					(const char *const *)extra_args);
+		for (i = 0; i < extra_args_num; i++)
+			debug("antispam: reaver extra arg %s\n",
+			      extra_args[i]);
+	}
+
+	signature_init();
+}
+
+void backend_exit(void)
+{
+}