From 986a34a6834795f1a2d25bcffbe67debf9bbd6b2 Mon Sep 17 00:00:00 2001 From: Zbigniew Jędrzejewski-Szmek Date: Thu, 18 Aug 2016 23:09:29 -0400 Subject: core/dynamic-users: warn when creation of symlinks for dynamic users fails Also return the first error, since it's most likely to be interesting. If unlink fails, symlink will usually return EEXIST. --- src/core/dynamic-user.c | 31 +++++++++++++++++-------------- 1 file changed, 17 insertions(+), 14 deletions(-) (limited to 'src') diff --git a/src/core/dynamic-user.c b/src/core/dynamic-user.c index 185d0e5f00..53c1699b92 100644 --- a/src/core/dynamic-user.c +++ b/src/core/dynamic-user.c @@ -154,7 +154,7 @@ static int make_uid_symlinks(uid_t uid, const char *name, bool b) { char path1[strlen("/run/systemd/dynamic-uid/direct:") + DECIMAL_STR_MAX(uid_t) + 1]; const char *path2; - int r = 0; + int r = 0, k; /* Add direct additional symlinks for direct lookups of dynamic UIDs and their names by userspace code. The * only reason we have this is because dbus-daemon cannot use D-Bus for resolving users and groups (since it @@ -164,23 +164,26 @@ static int make_uid_symlinks(uid_t uid, const char *name, bool b) { * on them and as those may be taken by any user with read access we can't make them world-readable. */ xsprintf(path1, "/run/systemd/dynamic-uid/direct:" UID_FMT, uid); - if (unlink(path1) < 0) { - if (errno != ENOENT) - r = -errno; - } - if (b) { - if (symlink(name, path1) < 0) - r = -errno; + if (unlink(path1) < 0 && errno != ENOENT) + r = -errno; + + if (b && symlink(name, path1) < 0) { + k = log_warning_errno(errno, "Failed to symlink \"%s\": %m", path1); + if (r == 0) + r = k; } path2 = strjoina("/run/systemd/dynamic-uid/direct:", name); - if (unlink(path2) < 0) { - if (errno != ENOENT) - r = -errno; + if (unlink(path2) < 0 && errno != ENOENT) { + k = -errno; + if (r == 0) + r = k; } - if (b) { - if (symlink(path1 + strlen("/run/systemd/dynamic-uid/direct:"), path2) < 0) - r = -errno; + + if (b && symlink(path1 + strlen("/run/systemd/dynamic-uid/direct:"), path2) < 0) { + k = log_warning_errno(errno, "Failed to symlink \"%s\": %m", path2); + if (r == 0) + r = k; } return r; -- cgit v1.2.3-54-g00ecf From 61755fdae08fffd72229feb52af74a85a9e0c8f7 Mon Sep 17 00:00:00 2001 From: Zbigniew Jędrzejewski-Szmek Date: Thu, 18 Aug 2016 23:19:10 -0400 Subject: journald: do not create split journals for dynamic users Dynamic users should be treated like system users, and their logs should end up in the main system journal. --- src/basic/user-util.h | 16 ++++++++++++++-- src/core/dynamic-user.c | 17 ++++------------- src/journal/journald-server.c | 2 +- 3 files changed, 19 insertions(+), 16 deletions(-) (limited to 'src') diff --git a/src/basic/user-util.h b/src/basic/user-util.h index 36f71fb004..f569363811 100644 --- a/src/basic/user-util.h +++ b/src/basic/user-util.h @@ -20,6 +20,7 @@ ***/ #include +#include #include #include @@ -57,8 +58,19 @@ int take_etc_passwd_lock(const char *root); #define UID_INVALID ((uid_t) -1) #define GID_INVALID ((gid_t) -1) -/* The following macros add 1 when converting things, since UID 0 is a - * valid UID, while the pointer NULL is special */ +/* Let's pick a UIDs within the 16bit range, so that we are compatible with containers using 16bit + * user namespacing. At least on Fedora normal users are allocated until UID 60000, hence do not + * allocate from below this. Also stay away from the upper end of the range as that is often used + * for overflow/nobody users. */ +#define DYNAMIC_UID_MIN ((uid_t) UINT32_C(0x0000EF00)) +#define DYNAMIC_UID_MAX ((uid_t) UINT32_C(0x0000FFEF)) + +static inline bool uid_is_dynamic(uid_t uid) { + return DYNAMIC_UID_MIN <= uid && uid <= DYNAMIC_UID_MAX; +} + +/* The following macros add 1 when converting things, since UID 0 is a valid UID, while the pointer + * NULL is special */ #define PTR_TO_UID(p) ((uid_t) (((uintptr_t) (p))-1)) #define UID_TO_PTR(u) ((void*) (((uintptr_t) (u))+1)) diff --git a/src/core/dynamic-user.c b/src/core/dynamic-user.c index 53c1699b92..310aaa94e1 100644 --- a/src/core/dynamic-user.c +++ b/src/core/dynamic-user.c @@ -31,14 +31,8 @@ #include "user-util.h" #include "fileio.h" -/* Let's pick a UIDs within the 16bit range, so that we are compatible with containers using 16bit user namespacing. At - * least on Fedora normal users are allocated until UID 60000, hence do not allocate from below this. Also stay away - * from the upper end of the range as that is often used for overflow/nobody users. */ -#define UID_PICK_MIN ((uid_t) UINT32_C(0x0000EF00)) -#define UID_PICK_MAX ((uid_t) UINT32_C(0x0000FFEF)) - /* Takes a value generated randomly or by hashing and turns it into a UID in the right range */ -#define UID_CLAMP_INTO_RANGE(rnd) (((uid_t) (rnd) % (UID_PICK_MAX - UID_PICK_MIN + 1)) + UID_PICK_MIN) +#define UID_CLAMP_INTO_RANGE(rnd) (((uid_t) (rnd) % (DYNAMIC_UID_MAX - DYNAMIC_UID_MIN + 1)) + DYNAMIC_UID_MIN) static DynamicUser* dynamic_user_free(DynamicUser *d) { if (!d) @@ -214,7 +208,7 @@ static int pick_uid(const char *name, uid_t *ret_uid) { if (--n_tries <= 0) /* Give up retrying eventually */ return -EBUSY; - if (candidate < UID_PICK_MIN || candidate > UID_PICK_MAX) + if (!uid_is_dynamic(candidate)) goto next; xsprintf(lock_path, "/run/systemd/dynamic-uid/" UID_FMT, candidate); @@ -676,11 +670,8 @@ int dynamic_user_lookup_uid(Manager *m, uid_t uid, char **ret) { assert(m); assert(ret); - /* A friendly way to translate a dynamic user's UID into a his name. */ - - if (uid < UID_PICK_MIN) - return -ESRCH; - if (uid > UID_PICK_MAX) + /* A friendly way to translate a dynamic user's UID into a name. */ + if (!uid_is_dynamic(uid)) return -ESRCH; xsprintf(lock_path, "/run/systemd/dynamic-uid/" UID_FMT, uid); diff --git a/src/journal/journald-server.c b/src/journal/journald-server.c index 443b2a4cd7..2a043a95b1 100644 --- a/src/journal/journald-server.c +++ b/src/journal/journald-server.c @@ -370,7 +370,7 @@ static JournalFile* find_journal(Server *s, uid_t uid) { if (s->runtime_journal) return s->runtime_journal; - if (uid <= SYSTEM_UID_MAX) + if (uid <= SYSTEM_UID_MAX || uid_is_dynamic(uid)) return s->system_journal; r = sd_id128_get_machine(&machine); -- cgit v1.2.3-54-g00ecf