From: Lennart Poettering Date: Fri, 26 Jan 2024 16:09:02 +0000 (+0100) Subject: sd-bus: also read supplementary gids from bus driver X-Git-Tag: v256-rc1~1021^2~5 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=25fd5343ca3a3481d2e0d3f3aebab2fcf4e42bc7;p=thirdparty%2Fsystemd.git sd-bus: also read supplementary gids from bus driver --- diff --git a/src/libsystemd/sd-bus/bus-control.c b/src/libsystemd/sd-bus/bus-control.c index 3b11d754a22..0953b6ab26c 100644 --- a/src/libsystemd/sd-bus/bus-control.c +++ b/src/libsystemd/sd-bus/bus-control.c @@ -483,8 +483,8 @@ _public_ int sd_bus_get_name_creds( } if (mask != 0) { + bool need_pid, need_uid, need_gids, need_selinux, need_separate_calls, need_pidfd, need_augment; _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; - bool need_pid, need_uid, need_selinux, need_separate_calls, need_pidfd, need_augment; _cleanup_(pidref_done) PidRef pidref = PIDREF_NULL; c = bus_creds_new(); @@ -513,10 +513,11 @@ _public_ int sd_bus_get_name_creds( need_pid = (mask & SD_BUS_CREDS_PID) || need_augment; need_uid = mask & SD_BUS_CREDS_EUID; + need_gids = mask & SD_BUS_CREDS_SUPPLEMENTARY_GIDS; need_selinux = mask & SD_BUS_CREDS_SELINUX_CONTEXT; need_pidfd = (mask & SD_BUS_CREDS_PIDFD) || need_augment; - if (need_pid + need_uid + need_selinux + need_pidfd > 1) { + if (need_pid + need_uid + need_selinux + need_pidfd + need_gids > 1) { /* If we need more than one of the credentials, then use GetConnectionCredentials() */ @@ -626,6 +627,49 @@ _public_ int sd_bus_get_name_creds( close_and_replace(c->pidfd, fd); c->mask |= SD_BUS_CREDS_PIDFD; } + } else if (need_gids && streq(m, "UnixGroupIDs")) { + + /* Note that D-Bus actualy only gives us a combined list of + * primary gid and supplementary gids. And we don't know + * which one the primary one is. We'll take the whole shebang + * hence and use it as the supplementary group list, and not + * initialize the primary gid field. This is slightly + * incorrect of course, but only slightly, as in effect if + * the primary gid is also listed in the supplementary gid + * it has zero effect. */ + + r = sd_bus_message_enter_container(reply, 'v', "au"); + if (r < 0) + return r; + + r = sd_bus_message_enter_container(reply, 'a', "u"); + if (r < 0) + return r; + + for (;;) { + uint32_t u; + + r = sd_bus_message_read(reply, "u", &u); + if (r < 0) + return r; + if (r == 0) + break; + + if (!GREEDY_REALLOC(c->supplementary_gids, c->n_supplementary_gids+1)) + return -ENOMEM; + + c->supplementary_gids[c->n_supplementary_gids++] = (gid_t) u; + } + + r = sd_bus_message_exit_container(reply); + if (r < 0) + return r; + + r = sd_bus_message_exit_container(reply); + if (r < 0) + return r; + + c->mask |= SD_BUS_CREDS_SUPPLEMENTARY_GIDS; } else { r = sd_bus_message_skip(reply, "v"); if (r < 0) diff --git a/src/libsystemd/sd-bus/test-bus-peersockaddr.c b/src/libsystemd/sd-bus/test-bus-peersockaddr.c index 0c57d382182..a7bba17a988 100644 --- a/src/libsystemd/sd-bus/test-bus-peersockaddr.c +++ b/src/libsystemd/sd-bus/test-bus-peersockaddr.c @@ -10,7 +10,34 @@ #include "fd-util.h" #include "process-util.h" #include "socket-util.h" +#include "sort-util.h" #include "tests.h" +#include "user-util.h" + +static bool gid_list_contained(const gid_t *a, size_t n, const gid_t *b, size_t m) { + assert_se(a || n == 0); + assert_se(b || m == 0); + + /* Checks if every entry in a[] is also in b[] */ + + for (size_t i = 0; i < n; i++) { + size_t j; + + for (j = 0; j < m; j++) + if (a[i] == b[j]) + break; + + if (j >= m) + return false; + } + + return true; +} + +static bool gid_list_same(const gid_t *a, size_t n, const gid_t *b, size_t m) { + return gid_list_contained(a, n, b, m) && + gid_list_contained(b, m, a, n); +} static void *server(void *p) { _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL; @@ -29,11 +56,11 @@ static void *server(void *p) { assert_se(sd_bus_set_fd(bus, fd, fd) >= 0); TAKE_FD(fd); assert_se(sd_bus_set_server(bus, true, id) >= 0); - assert_se(sd_bus_negotiate_creds(bus, 1, SD_BUS_CREDS_EUID|SD_BUS_CREDS_EGID|SD_BUS_CREDS_PID|SD_BUS_CREDS_COMM|SD_BUS_CREDS_DESCRIPTION|SD_BUS_CREDS_PIDFD) >= 0); + assert_se(sd_bus_negotiate_creds(bus, 1, SD_BUS_CREDS_EUID|SD_BUS_CREDS_EGID|SD_BUS_CREDS_PID|SD_BUS_CREDS_COMM|SD_BUS_CREDS_DESCRIPTION|SD_BUS_CREDS_PIDFD|SD_BUS_CREDS_SUPPLEMENTARY_GIDS) >= 0); assert_se(sd_bus_start(bus) >= 0); - assert_se(sd_bus_get_owner_creds(bus, SD_BUS_CREDS_EUID|SD_BUS_CREDS_EGID|SD_BUS_CREDS_PID|SD_BUS_CREDS_COMM|SD_BUS_CREDS_DESCRIPTION|SD_BUS_CREDS_PIDFD, &c) >= 0); + assert_se(sd_bus_get_owner_creds(bus, SD_BUS_CREDS_EUID|SD_BUS_CREDS_EGID|SD_BUS_CREDS_PID|SD_BUS_CREDS_COMM|SD_BUS_CREDS_DESCRIPTION|SD_BUS_CREDS_PIDFD|SD_BUS_CREDS_SUPPLEMENTARY_GIDS, &c) >= 0); bus_creds_dump(c, /* f= */ NULL, /* terse= */ false); @@ -57,6 +84,18 @@ static void *server(void *p) { assert_se(pidref.pid == getpid_cached()); } + const gid_t *gl = NULL; + int n; + n = sd_bus_creds_get_supplementary_gids(c, &gl); + + if (n >= 0) { + _cleanup_free_ gid_t *gg = NULL; + r = getgroups_alloc(&gg); + assert_se(r >= 0); + + assert_se(gid_list_same(gl, n, gg, r)); + } + const char *comm; assert_se(sd_bus_creds_get_comm(c, &comm) >= 0); assert_se(pid_get_comm(0, &our_comm) >= 0);