exmdb: add unique per-process identifier for eml object filenames

Cure a case of E-5310 appearing in log messages which can happen if
lib/ruleproc.cpp processes a OP_MOVE/OP_COPY rule.

E-5310: link /var/lib/gromox/user/horio/eml/1753728954.1.a4.inai.de ->
/var/lib/gromox/user/horio/eml/1753728954.1.a4.inai.de: File exists

exmdb's copy_eml_ext() is prone to derive a new_name that is equal to
old_name. gromox-delivery creates e.g. 1234567890.1.hostname, and
exmdb can too if their sequence number lines up.

Author: jengelh

Makefile.am

@@ -103,7 +103,7 @@ libgxm_alias_resolve_la_LIBADD = -lpthread ${libHX_LIBS} ${mysql_LIBS} libgromox
 EXTRA_libgxm_alias_resolve_la_DEPENDENCIES = default.sym
 libgxm_exmdb_local_la_SOURCES = lib/bounce_mda.cpp mda/exmdb_local/auto_response.cpp mda/exmdb_local/bounce_audit.cpp mda/exmdb_local/bounce_producer.cpp mda/exmdb_local/cache_queue.cpp mda/exmdb_local/exmdb_local.cpp mda/exmdb_local/exmdb_local.hpp
 libgxm_exmdb_local_la_LDFLAGS = ${default_SYFLAGS}
-libgxm_exmdb_local_la_LIBADD = -lpthread ${libHX_LIBS} ${jsoncpp_LIBS} libgromox_common.la libgromox_exrpc.la libgromox_mapi.la libgxs_mysql_adaptor.la
+libgxm_exmdb_local_la_LIBADD = -lpthread ${fmt_LIBS} ${libHX_LIBS} ${jsoncpp_LIBS} libgromox_common.la libgromox_exrpc.la libgromox_mapi.la libgxs_mysql_adaptor.la
 EXTRA_libgxm_exmdb_local_la_DEPENDENCIES = default.sym
 
 pop3_SOURCES = mra/pop3/cmd.cpp mra/pop3/main.cpp mra/pop3/parser.cpp mra/pop3/pop3.hpp mra/pop3/resource.cpp

exch/exmdb/common_util.cpp

@@ -4696,7 +4696,7 @@ BOOL common_util_check_message_owner(sqlite3 *psqlite,
 static errno_t copy_eml_ext(const char *old_midstr, std::string &new_midstr) try
 {
 	auto basedir = exmdb_server::get_dir();
-	new_midstr = fmt::format("{}.{}.{}", time(nullptr), common_util_sequence_ID(), get_host_ID());
+	new_midstr = fmt::format("{}.x{}.{}", time(nullptr), common_util_sequence_ID(), get_host_ID());
 	auto old_eml = fmt::format("{}/eml/{}", basedir, old_midstr);
 	auto new_eml = fmt::format("{}/eml/{}", basedir, new_midstr);
 	/*

exch/exmdb/message.cpp

@@ -3099,9 +3099,8 @@ static ec_error_t op_delegate(const rulexec_in &rp, seen_list &seen,
 				tmp_path1, eaddr.c_str());
 			continue;
 		}
-		auto mid_string = std::to_string(time(nullptr)) + "." +
-				  std::to_string(common_util_sequence_ID()) + "." +
-				  get_host_ID();
+		auto mid_string = fmt::format("{}.x{}.{}", time(nullptr),
+		                  common_util_sequence_ID(), get_host_ID());
 		auto eml_path = maildir + "/eml/"s + mid_string;
 		auto ret = HX_copy_file(tmp_path1, eml_path.c_str(), 0);
 		if (ret < 0) {
@@ -3406,9 +3405,8 @@ static ec_error_t opx_delegate(const rulexec_in &rp, const rule_node &rule,
 		if (mysql_adaptor_meta(eaddr.c_str(), WANTPRIV_METAONLY, mres) != 0)
 			continue;
 		auto maildir = mres.maildir.c_str();
-		auto mid_string = std::to_string(time(nullptr)) + "." +
-				  std::to_string(common_util_sequence_ID()) + "." +
-				  get_host_ID();
+		auto mid_string = fmt::format("{}.x{}.{}", time(nullptr),
+		                  common_util_sequence_ID(), get_host_ID());
 		auto eml_path = maildir + "/eml/"s + mid_string;
 		auto ret = HX_copy_file(tmp_path1, eml_path.c_str(), 0);
 		if (ret < 0) {

exch/midb/mail_engine.cpp

@@ -1368,7 +1368,7 @@ static void me_insert_message(xstmt &stm_insert, uint32_t *puidnext,
 			return;
 		digest["file"] = "";
 		djson = json_to_str(digest);
-		e.midstr = std::to_string(time(nullptr)) + "." + std::to_string(++g_sequence_id) + ".midb";
+		e.midstr = fmt::format("{}.m{}.{}", time(nullptr), ++g_sequence_id, g_host_id);
 		if (!exmdb_client->imapfile_write(dir, "ext", e.midstr, djson)) {
 			mlog(LV_ERR, "E-1770: imapfile_write %s/ext/%s incomplete", dir, e.midstr.c_str());
 			return;

exch/midb/mail_engine.hpp

@@ -12,3 +12,4 @@ extern void me_stop();
 
 extern unsigned int g_midb_schema_upgrades;
 extern unsigned int g_midb_cache_interval, g_midb_reload_interval;
+extern std::string g_host_id;

exch/midb/main.cpp

@@ -53,6 +53,7 @@ void (*system_services_broadcast_event)(const char*);
 
 static gromox::atomic_bool g_main_notify_stop, g_listener_notify_stop;
 std::shared_ptr<CONFIG_FILE> g_config_file;
+std::string g_host_id;
 static char *opt_config_file;
 static unsigned int opt_show_version;
 static gromox::atomic_bool g_hup_signalled;
@@ -307,6 +308,18 @@ int main(int argc, char **argv)
 	if (!midb_reload_config(gxconfig, pconfig))
 		return EXIT_FAILURE;
 
+	auto str_val = g_config_file->get_value("host_id");
+	if (str_val == nullptr) {
+		std::string hn;
+		auto ret = canonical_hostname(hn);
+		if (ret != 0)
+			return EXIT_FAILURE;
+		g_config_file->set_value("host_id", hn.c_str());
+		g_host_id = std::move(hn);
+	} else {
+		g_host_id = str_val;
+	}
+
 	int proxy_num = pconfig->get_ll("rpc_proxy_connection_num");
 	mlog(LV_INFO, "system: exmdb proxy connection number is %d", proxy_num);
 

mda/exmdb_local/exmdb_local.cpp

@@ -14,6 +14,7 @@
 #include <string>
 #include <unistd.h>
 #include <vector>
+#include <fmt/core.h>
 #include <libHX/string.h>
 #include <sys/stat.h>
 #include <gromox/bounce_gen.hpp>
@@ -286,8 +287,7 @@ delivery_status exmdb_local_deliverquota(MESSAGE_CONTEXT *pcontext,
 		else
 			hostname[std::size(hostname)-1] = '\0';
 	}
-	auto mid_string = std::to_string(time(nullptr)) + "." +
-	                  std::to_string(sequence_ID) + "." + hostname;
+	auto mid_string = fmt::format("{}.l{}.{}", time(nullptr), sequence_ID, hostname);
 	auto eml_path = mres.maildir + "/eml/" + mid_string;
 	wrapfd fd = open(eml_path.c_str(), O_CREAT | O_RDWR | O_TRUNC, FMODE_PRIVATE);
 	if (fd.get() < 0) {

mra/imap/cmd.cpp

@@ -2113,7 +2113,7 @@ static int icp_long_append_begin2(int argc, char **argv, imap_context &ctx) try
 				return 1800 | DISPATCH_BREAK;
 	}
 	auto pcontext = &ctx;
-	pcontext->mid = fmt::format("{}.{}.{}",
+	pcontext->mid = fmt::format("{}.i{}.{}",
 	                time(nullptr), imap_parser_get_sequence_ID(),
 	                znul(g_config_file->get_value("host_id")));
 	ctx.append_stream.clear();

tools/mbsize.cpp

@@ -88,6 +88,18 @@ static double ratio_sav(double old, double nu)
 	return 100 * (1 - nu / old);
 }
 
+static bool looks_like_midb_generated(const char *name)
+{
+	auto dot = strchr(name, '.');
+	if (dot == nullptr)
+		return false;
+	if (dot[1] == 'm' && strtoul(&dot[2], nullptr, 10) != 0)
+		return true;
+	if (class_match_suffix(name, ".midb") == 0)
+		return true;
+	return false;
+}
+
 static struct rfc_stat rfc_count(const std::string &dirname)
 {
 	struct rfc_stat out;
@@ -111,7 +123,7 @@ static struct rfc_stat rfc_count(const std::string &dirname)
 		if (fstatat(dfd, name, &sb, 0) != 0 ||
 		    !S_ISREG(sb.st_mode))
 			continue;
-		if (class_match_suffix(name, ".midb") == 0)
+		if (looks_like_midb_generated(name))
 			out.sent += sb;
 		else
 			out.recv += sb;