add 1.1 storage. probably doesn't work

1 files changed, 509 insertions, 0 deletions

diff --git a/antispam-storage-1.1.c b/antispam-storage-1.1.c
new file mode 100644
index 0000000..372f3a6
--- /dev/null
+++ b/antispam-storage-1.1.c
@@ -0,0 +1,509 @@
+/*
+ * Storage implementation for antispam plugin
+ * Copyright 2007-2008	Johannes Berg <johannes@sipsolutions.net>
+ *
+ * Derived from Quota plugin:
+ * Copyright (C) 2005 Timo Sirainen
+ */
+
+#include <sys/stat.h>
+
+#include "lib.h"
+#include "array.h"
+#include "istream.h"
+#include "mail-search.h"
+#include "mail-index.h"
+#include "mailbox-list-private.h"
+#include "mail-storage-private.h"
+
+#include "antispam-plugin.h"
+
+#define ANTISPAM_CONTEXT(obj) \
+	MODULE_CONTEXT(obj, antispam_storage_module)
+#define ANTISPAM_MAIL_CONTEXT(obj) \
+	MODULE_CONTEXT(obj, antispam_mail_module)
+
+static MODULE_CONTEXT_DEFINE_INIT(antispam_storage_module,
+                                  &mail_storage_module_register);
+static MODULE_CONTEXT_DEFINE_INIT(antispam_mail_module,
+                                  &mail_module_register);
+
+                                 
+struct antispam_mail_storage {
+	union mail_storage_module_context module_ctx;
+	struct antispam *antispam;
+};
+
+enum mailbox_move_type {
+	MMT_APPEND,
+	MMT_UNINTERESTING,
+	MMT_TO_CLEAN,
+	MMT_TO_SPAM,
+};
+
+struct antispam_internal_context {
+	union mailbox_transaction_module_context module_ctx;
+	struct antispam_transaction_context *backendctx;
+	struct mail *mail;
+};
+
+enum classification move_to_class(enum mailbox_move_type tp)
+{
+	switch (tp) {
+	case MMT_TO_CLEAN:
+		return CLASS_NOTSPAM;
+	case MMT_TO_SPAM:
+		return CLASS_SPAM;
+	default:
+		i_assert(0);
+	}
+}
+
+struct antispam_mailbox {
+	union mailbox_module_context module_ctx;
+
+	enum mailbox_move_type movetype;
+
+	/* used to check if copy was implemented with save */
+	unsigned int save_hack:1;
+};
+
+struct antispam_mail {
+	union mail_module_context module_ctx;
+};
+
+static uint32_t antispam_storage_module_id = 0;
+static bool antispam_storage_module_id_set = FALSE;
+
+static int
+antispam_copy(struct mailbox_transaction_context *t, struct mail *mail,
+	      enum mail_flags flags, struct mail_keywords *keywords,
+	      struct mail *dest_mail)
+{
+	struct antispam_mailbox *asbox = ANTISPAM_CONTEXT(t->box);
+	struct antispam_internal_context *ast = ANTISPAM_CONTEXT(t);
+	struct mail *copy_dest_mail;
+	int ret;
+	bool src_trash, dst_trash;
+
+	if (dest_mail != NULL)
+		copy_dest_mail = dest_mail;
+	else
+		copy_dest_mail = mail_alloc(t, MAIL_FETCH_PHYSICAL_SIZE, NULL);
+
+	i_assert(mail->box);
+
+	asbox->save_hack = FALSE;
+	asbox->movetype = MMT_UNINTERESTING;
+
+	if (mailbox_is_unsure(t->box)) {
+		mail_storage_set_error(t->box->storage, MAIL_ERROR_NOTPOSSIBLE,
+				       "Cannot copy to unsure folder");
+		return -1;
+	}
+
+	src_trash = mailbox_is_trash(mail->box);
+	dst_trash = mailbox_is_trash(t->box);
+
+	debug_verbose("mail copy: from trash: %d, to trash: %d\n",
+	              src_trash, dst_trash);
+
+	if (!src_trash && !dst_trash) {
+		bool src_spam = mailbox_is_spam(mail->box);
+		bool dst_spam = mailbox_is_spam(t->box);
+		bool src_unsu = mailbox_is_unsure(mail->box);
+
+		debug_verbose("mail copy: src spam: %d, dst spam: %d,"
+		              " src unsure: %d\n",
+		              src_spam, dst_spam, src_unsu);
+
+		if ((src_spam || src_unsu) && !dst_spam)
+			asbox->movetype = MMT_TO_CLEAN;
+		else if ((!src_spam || src_unsu) && dst_spam)
+			asbox->movetype = MMT_TO_SPAM;
+	}
+
+	if (asbox->module_ctx.super.copy(t, mail, flags, keywords, copy_dest_mail) < 0)
+		return -1;
+
+	/*
+	 * If copying used saving internally, we already have treated the mail
+	 */
+	if (asbox->save_hack || asbox->movetype == MMT_UNINTERESTING)
+		ret = 0;
+	else
+		ret = backend_handle_mail(t, ast->backendctx, copy_dest_mail,
+					  move_to_class(asbox->movetype));
+
+	/*
+	 * Both save_hack and movetype are only valid within a copy operation,
+	 * i.e. they are now invalid. Because, in theory, another operation
+	 * could be done after mailbox_open(), we need to reset the movetype
+	 * variable here. save_hack doesn't need to be reset because it is
+	 * only ever set within the save function and tested within this copy
+	 * function after being reset at the beginning of the copy, movetype
+	 * however is tested within the save_finish() function and a subsequent
+	 * save to the mailbox should not invoke the backend.
+	 */
+	asbox->movetype = MMT_APPEND;
+
+	if (copy_dest_mail != dest_mail)
+		mail_free(&copy_dest_mail);
+	return ret;
+}
+
+static int antispam_save_init(struct mailbox_transaction_context *t,
+			      enum mail_flags flags,
+			      struct mail_keywords *keywords,
+			      time_t received_date, int timezone_offset,
+			      const char *from_envelope, struct istream *input,
+			      struct mail *dest_mail, struct mail_save_context **ctx_r)
+{
+	struct antispam_internal_context *ast = ANTISPAM_CONTEXT(t);
+	struct antispam_mailbox *asbox = ANTISPAM_CONTEXT(t->box);
+
+	if (!dest_mail && !ast->mail) {
+		ast->mail = mail_alloc(t, MAIL_FETCH_STREAM_HEADER |
+					  MAIL_FETCH_STREAM_BODY, NULL);
+		dest_mail = ast->mail;
+	}
+	return asbox->module_ctx.super.save_init(t, flags, keywords, received_date,
+				      timezone_offset, from_envelope,
+				      input, dest_mail, ctx_r);
+}
+
+static int antispam_save_finish(struct mail_save_context *ctx)
+{
+	struct antispam_mailbox *asbox =
+		ANTISPAM_CONTEXT(ctx->transaction->box);
+	struct antispam_internal_context *ast =
+		ANTISPAM_CONTEXT(ctx->transaction);
+	struct mail *dest_mail = ast->mail;
+	int ret;
+
+	if (asbox->module_ctx.super.save_finish(ctx) < 0)
+		return -1;
+
+	asbox->save_hack = TRUE;
+
+	ret = 0;
+
+	switch (asbox->movetype) {
+	case MMT_UNINTERESTING:
+		break;
+	case MMT_APPEND:
+		/* Disallow APPENDs to UNSURE folders. */
+		if (mailbox_is_unsure(dest_mail->box)) {
+			ret = -1;
+			mail_storage_set_error(dest_mail->box->storage,
+					MAIL_ERROR_NOTPOSSIBLE,
+					"Cannot APPEND to an UNSURE folder.");
+			break;
+		} else if (mailbox_is_spam(dest_mail->box)) {
+			/*
+			 * The client is APPENDing a message to a SPAM folder
+			 * so we try to train the backend on it. For most of
+			 * the backends, that can only succeed if the message
+			 * contains appropriate information.
+			 *
+			 * This happens especially when offlineimap is used and
+			 * the user moved a message to the SPAM folder while
+			 * offline---offlineimap cannot reproduce the COPY but
+			 * rather APPENDs the moved message on the next sync.
+			 *
+			 * This could be a bad if the spam headers were not
+			 * generated on our server, but since the user can
+			 * always APPEND to another folder and then COPY to a
+			 * SPAM folder backends need to be prepared for cases
+			 * like this anyway. With dspam, for example, the worst
+			 * that can happen is that the APPEND fails with a
+			 * training error from dspam.
+			 *
+			 * Unfortunately, we cannot handle the cases where
+			 *  (1) the user moved a message from one folder that
+			 *      contains SPAM to another folder containing SPAM
+			 *  (2) the user moved a message out of the SPAM folder
+			 *  (3) the user recovered a message from trash
+			 *
+			 * Because of these limitations, this behaviour needs
+			 * to be enabled with an option.
+			 */
+			if (!antispam_can_append_to_spam) {
+				ret = -1;
+				mail_storage_set_error(
+					dest_mail->box->storage,
+					MAIL_ERROR_NOTPOSSIBLE,
+					"Cannot APPEND to a SPAM folder.");
+				break;
+			}
+			asbox->movetype = MMT_TO_SPAM;
+			/* fall through to default case to invoke backend */
+		} else {
+			/* neither UNSURE nor SPAM, regular folder */
+			break;
+		}
+		/* fall through */
+	default:
+		ret = backend_handle_mail(ctx->transaction, ast->backendctx,
+					  dest_mail,
+					  move_to_class(asbox->movetype));
+	}
+
+	return ret;
+}
+
+static struct antispam_transaction_context *
+antispam_transaction_begin(struct mailbox *box)
+{
+	struct antispam_transaction_context *ast;
+
+	ast = backend_start(box);
+	i_assert(ast != NULL);
+
+	return ast;
+}
+
+static void
+antispam_transaction_rollback(struct antispam_transaction_context **_ast)
+{
+	struct antispam_transaction_context *ast = *_ast;
+
+	backend_rollback(ast);
+	*_ast = NULL;
+}
+
+static int
+antispam_transaction_commit(struct mailbox_transaction_context *ctx,
+			    struct antispam_transaction_context **_ast)
+{
+	struct antispam_transaction_context *ast = *_ast;
+	int ret;
+
+	ret = backend_commit(ctx, ast);
+	*_ast = NULL;
+	return ret;
+}
+
+static void
+antispam_mail_update_keywords(struct mail *mail,
+			      enum modify_type modify_type,
+			      struct mail_keywords *keywords)
+{
+	struct mail_private *pmail = (struct mail_private *)mail;
+	struct antispam_mail *amail = ANTISPAM_MAIL_CONTEXT(pmail);
+	unsigned int i, numkwds;
+	const ARRAY_TYPE(keywords) *idxkwd = mail_index_get_keywords(keywords->index);
+	const char *const *keyword_names = array_get(idxkwd, &numkwds);
+	const char *const *orig_keywords;
+	bool previous_spam_keyword, now_spam_keyword;
+
+	switch (modify_type) {
+	case MODIFY_ADD:
+		debug("adding keyword(s)\n");
+		break;
+	case MODIFY_REMOVE:
+		debug("removing keyword(s)\n");
+		break;
+	case MODIFY_REPLACE:
+		debug("replacing keyword(s)\n");
+		break;
+	default:
+		i_assert(0);
+	}
+
+	orig_keywords = pmail->v.get_keywords(mail);
+	if (orig_keywords) {
+		debug("original keyword list:\n");
+		while (*orig_keywords) {
+			debug(" * %s\n", *orig_keywords);
+			if (keyword_is_spam(*orig_keywords))
+				previous_spam_keyword = TRUE;
+			orig_keywords++;
+		}
+	}
+
+	debug("keyword list:\n");
+
+	for (i = 0; i < keywords->count; i++) {
+		unsigned int idx = keywords->idx[i];
+
+		i_assert(idx < numkwds);
+
+		debug(" * %s\n", keyword_names[idx]);
+
+		switch (modify_type) {
+		case MODIFY_ADD:
+		case MODIFY_REPLACE:
+			if (keyword_is_spam(keyword_names[idx]))
+				now_spam_keyword = TRUE;
+			break;
+		case MODIFY_REMOVE:
+			if (keyword_is_spam(keyword_names[idx]))
+				now_spam_keyword = FALSE;
+			break;
+		default:
+			i_assert(0);
+		}
+	}
+
+	amail->module_ctx.super.update_keywords(mail, modify_type, keywords);
+
+	debug("previous-spam, now-spam: %d, %d\n",
+	      previous_spam_keyword, now_spam_keyword);
+
+	if (previous_spam_keyword != now_spam_keyword) {
+		/*
+		 * Call backend here.
+		 *
+		 * TODO: It is not clear how to roll back the
+		 *       keyword change if the backend fails.
+		 */
+	}
+}
+
+static void
+antispam_mail_free(struct mail *mail)
+{
+	struct mail_private *pmail = (struct mail_private *)mail;
+	struct antispam_mail *amail = ANTISPAM_MAIL_CONTEXT(pmail);
+
+	amail->module_ctx.super.free(mail);
+	i_free(amail);
+}
+
+static struct mailbox_transaction_context *
+antispam_mailbox_transaction_begin(struct mailbox *box,
+				   enum mailbox_transaction_flags flags)
+{
+	struct antispam_mailbox *asbox = ANTISPAM_CONTEXT(box);
+	struct mailbox_transaction_context *t;
+	struct antispam_transaction_context *ast;
+	struct antispam_internal_context *aic;
+
+	t = asbox->module_ctx.super.transaction_begin(box, flags);
+	aic = i_new(struct antispam_internal_context, 1);
+	ast = antispam_transaction_begin(box);
+	aic->backendctx = ast;
+
+	MODULE_CONTEXT_SET(t, antispam_storage_module, aic);
+	return t;
+}
+
+static int
+antispam_mailbox_transaction_commit(struct mailbox_transaction_context *ctx,
+				    uint32_t *uid_validity_r,
+				    uint32_t *first_saved_uid_r,
+				    uint32_t *last_saved_uid_r)
+{
+	struct antispam_mailbox *asbox = ANTISPAM_CONTEXT(ctx->box);
+	struct antispam_internal_context *ast = ANTISPAM_CONTEXT(ctx);
+
+	if (antispam_transaction_commit(ctx, &ast->backendctx) < 0) {
+		if (ast->mail)
+			mail_free(&ast->mail);
+
+		asbox->module_ctx.super.transaction_rollback(ctx);
+		return -1;
+	}
+
+	if (ast->mail)
+		mail_free(&ast->mail);
+
+	return asbox->module_ctx.super.transaction_commit(ctx, uid_validity_r,
+					       first_saved_uid_r,
+					       last_saved_uid_r);
+}
+
+static void
+antispam_mailbox_transaction_rollback(struct mailbox_transaction_context *ctx)
+{
+	struct antispam_mailbox *asbox = ANTISPAM_CONTEXT(ctx->box);
+	struct antispam_internal_context *ast = ANTISPAM_CONTEXT(ctx);
+
+	asbox->module_ctx.super.transaction_rollback(ctx);
+
+	if (ast->mail)
+		mail_free(&ast->mail);
+
+	antispam_transaction_rollback(&ast->backendctx);
+}
+
+static struct mail *
+antispam_mailbox_mail_alloc(struct mailbox_transaction_context *ctx,
+			    enum mail_fetch_field wanted_fields,
+			    struct mailbox_header_lookup_ctx *wanted_headers)
+{
+	struct antispam_mailbox *asbox = ANTISPAM_CONTEXT(ctx->box);
+	struct antispam_mail *amail = i_new(struct antispam_mail, 1);
+	struct mail_private *pmail;
+
+	/* XXX: is this cast the right thing to do? */
+	pmail = (struct mail_private *) asbox->module_ctx.super.mail_alloc(
+						ctx,
+						wanted_fields,
+						wanted_headers);
+
+	amail->module_ctx.super = pmail->v;
+
+	MODULE_CONTEXT_SET(pmail, antispam_mail_module, amail);
+
+	pmail->v.update_keywords = antispam_mail_update_keywords;
+	pmail->v.free = antispam_mail_free;
+
+	return (struct mail *)pmail;
+}
+
+static struct mailbox *antispam_mailbox_open(struct mail_storage *storage,
+					     const char *name,
+					     struct istream *input,
+					     enum mailbox_open_flags flags)
+{
+	struct antispam_mail_storage *as_storage = ANTISPAM_CONTEXT(storage);
+	struct mailbox *box;
+	struct antispam_mailbox *asbox;
+
+	box = as_storage->module_ctx.super.mailbox_open(storage, name, input, flags);
+	if (box == NULL)
+		return NULL;
+
+	asbox = p_new(box->pool, struct antispam_mailbox, 1);
+	asbox->module_ctx.super = box->v;
+	asbox->save_hack = FALSE;
+	asbox->movetype = MMT_APPEND;
+
+	if (need_folder_hook) {
+		/* override save_init to override want_mail, we need that */
+		box->v.save_init = antispam_save_init;
+		box->v.save_finish = antispam_save_finish;
+		box->v.transaction_begin = antispam_mailbox_transaction_begin;
+		box->v.transaction_commit = antispam_mailbox_transaction_commit;
+		box->v.transaction_rollback = antispam_mailbox_transaction_rollback;
+		box->v.copy = antispam_copy;
+	}
+
+	if (need_keyword_hook)
+		box->v.mail_alloc = antispam_mailbox_mail_alloc;
+
+	MODULE_CONTEXT_SET(box, antispam_storage_module, asbox);
+	return box;
+}
+
+void antispam_mail_storage_created(struct mail_storage *storage)
+{
+	struct antispam_mail_storage *as_storage;
+	union mail_storage_module_context *astorage;
+
+	if (antispam_next_hook_mail_storage_created != NULL)
+		antispam_next_hook_mail_storage_created(storage);
+
+	as_storage = p_new(storage->pool, struct antispam_mail_storage, 1);
+	as_storage->module_ctx.super = storage->v;
+	storage->v.mailbox_open = antispam_mailbox_open;
+
+	if (!antispam_storage_module_id_set) {
+		antispam_storage_module_id = PLUGIN_FUNCTION(id);
+		antispam_storage_module_id_set = TRUE;
+	}
+
+	MODULE_CONTEXT_SET_SELF(storage, antispam_storage_module, astorage);
+}