From: Mike Yuan Date: Tue, 23 Jul 2024 15:55:12 +0000 (+0200) Subject: core: reliably check if varlink socket has been deserialized X-Git-Tag: v257-rc1~827^2~3 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=d4e5c66ed469c822ca5346c7a445ec1446b1d17f;p=thirdparty%2Fsystemd.git core: reliably check if varlink socket has been deserialized Follow-up for 6906c028e83b77b35eaaf87b27d0fe5c6e1984b7 The mentioned commit uses access() to check if varlink socket already exists in the filesystem, but that isn't sufficient. > Varlink sockets are not serialized until v252, so upgrading from > v251 or older means we will not listen anymore on the varlink sockets. > > See https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1074789 > for more details as this was found when updating from Debian Bullseye to a new version. After this commit, the set up of varlink_server is effectively split into two steps. manager_varlink_init_system(), which is called after deserialization, would no longer skip listening even if Manager.varlink_server is in place, but actually check if we're listening on desired sockets. Then, manager_deserialize() can be switched back to using manager_setup_varlink_server(). Alternative to #33817 Co-authored-by: Luca Boccassi --- diff --git a/src/core/core-varlink.c b/src/core/core-varlink.c index a336430bf49..b22b8fb0c21 100644 --- a/src/core/core-varlink.c +++ b/src/core/core-varlink.c @@ -7,6 +7,7 @@ #include "mkdir-label.h" #include "strv.h" #include "user-util.h" +#include "varlink-internal.h" #include "varlink-io.systemd.UserDatabase.h" #include "varlink-io.systemd.ManagedOOM.h" @@ -500,12 +501,17 @@ static void vl_disconnect(sd_varlink_server *s, sd_varlink *link, void *userdata m->managed_oom_varlink = sd_varlink_unref(link); } -static int manager_setup_varlink_server(Manager *m, sd_varlink_server **ret) { +int manager_setup_varlink_server(Manager *m) { _cleanup_(sd_varlink_server_unrefp) sd_varlink_server *s = NULL; int r; assert(m); - assert(ret); + + if (m->varlink_server) + return 0; + + if (!MANAGER_IS_SYSTEM(m)) + return -EINVAL; r = sd_varlink_server_new(&s, SD_VARLINK_SERVER_ACCOUNT_UID|SD_VARLINK_SERVER_INHERIT_USERDATA); if (r < 0) @@ -533,51 +539,51 @@ static int manager_setup_varlink_server(Manager *m, sd_varlink_server **ret) { if (r < 0) return log_debug_errno(r, "Failed to register varlink disconnect handler: %m"); - *ret = TAKE_PTR(s); - return 0; + r = sd_varlink_server_attach_event(s, m->event, EVENT_PRIORITY_IPC); + if (r < 0) + return log_debug_errno(r, "Failed to attach varlink connection to event loop: %m"); + + m->varlink_server = TAKE_PTR(s); + return 1; } static int manager_varlink_init_system(Manager *m) { - _cleanup_(sd_varlink_server_unrefp) sd_varlink_server *s = NULL; int r; assert(m); - if (m->varlink_server) - return 1; - if (!MANAGER_IS_SYSTEM(m)) return 0; - r = manager_setup_varlink_server(m, &s); + r = manager_setup_varlink_server(m); if (r < 0) return log_error_errno(r, "Failed to set up varlink server: %m"); + bool fresh = r > 0; if (!MANAGER_IS_TEST_RUN(m)) { (void) mkdir_p_label("/run/systemd/userdb", 0755); FOREACH_STRING(address, "/run/systemd/userdb/io.systemd.DynamicUser", VARLINK_ADDR_PATH_MANAGED_OOM_SYSTEM) { - if (MANAGER_IS_RELOADING(m)) { - /* If manager is reloading, we skip listening on existing addresses, since - * the fd should be acquired later through deserialization. */ - if (access(address, F_OK) >= 0) + if (!fresh) { + /* We might have got sockets through deserialization. Do not bind to them twice. */ + + bool found = false; + LIST_FOREACH(sockets, ss, m->varlink_server->sockets) + if (path_equal(ss->address, address)) { + found = true; + break; + } + + if (found) continue; - if (errno != ENOENT) - return log_error_errno(errno, - "Failed to check if varlink socket '%s' exists: %m", address); } - r = sd_varlink_server_listen_address(s, address, 0666); + r = sd_varlink_server_listen_address(m->varlink_server, address, 0666); if (r < 0) return log_error_errno(r, "Failed to bind to varlink socket '%s': %m", address); } } - r = sd_varlink_server_attach_event(s, m->event, EVENT_PRIORITY_IPC); - if (r < 0) - return log_error_errno(r, "Failed to attach varlink connection to event loop: %m"); - - m->varlink_server = TAKE_PTR(s); return 1; } diff --git a/src/core/core-varlink.h b/src/core/core-varlink.h index 20507a41874..4b776200289 100644 --- a/src/core/core-varlink.h +++ b/src/core/core-varlink.h @@ -3,6 +3,8 @@ #include "manager.h" +int manager_setup_varlink_server(Manager *m); + int manager_varlink_init(Manager *m); void manager_varlink_done(Manager *m); diff --git a/src/core/manager-serialize.c b/src/core/manager-serialize.c index 8d998d40c17..62dfce93a0a 100644 --- a/src/core/manager-serialize.c +++ b/src/core/manager-serialize.c @@ -508,7 +508,7 @@ int manager_deserialize(Manager *m, FILE *f, FDSet *fds) { return r; } else if ((val = startswith(l, "varlink-server-socket-address="))) { if (!m->varlink_server && MANAGER_IS_SYSTEM(m)) { - r = manager_varlink_init(m); + r = manager_setup_varlink_server(m); if (r < 0) { log_warning_errno(r, "Failed to setup varlink server, ignoring: %m"); continue;