diff --git a/login/utmp_file.c b/login/utmp_file.c index 917c4c56ed..c41d17b450 100644 --- a/login/utmp_file.c +++ b/login/utmp_file.c @@ -43,6 +43,25 @@ static off64_t file_offset; /* Cache for the last read entry. */ static struct utmp last_entry; +/* Returns true if *ENTRY matches last_entry, based on + data->ut_type. */ +static bool +matches_last_entry (const struct utmp *data) +{ + if (file_offset <= 0) + /* Nothing has been read. last_entry is stale and cannot match. */ + return false; + + if (data->ut_type == RUN_LVL + || data->ut_type == BOOT_TIME + || data->ut_type == OLD_TIME + || data->ut_type == NEW_TIME) + /* For some entry types, only a type match is required. */ + return data->ut_type == last_entry.ut_type; + else + /* For the process-related entries, a full match is needed. */ + return __utmp_equal (&last_entry, data); +} /* Locking timeout. */ #ifndef TIMEOUT @@ -133,9 +152,6 @@ __libc_setutent (void) __lseek64 (file_fd, 0, SEEK_SET); file_offset = 0; - /* Make sure the entry won't match. */ - last_entry.ut_type = -1; - return 1; } @@ -191,48 +207,20 @@ __libc_getutent_r (struct utmp *buffer, struct utmp **result) static int internal_getut_nolock (const struct utmp *id) { - if (id->ut_type == RUN_LVL || id->ut_type == BOOT_TIME - || id->ut_type == OLD_TIME || id->ut_type == NEW_TIME) + while (1) { - /* Search for next entry with type RUN_LVL, BOOT_TIME, - OLD_TIME, or NEW_TIME. */ - - while (1) + /* Read the next entry. */ + if (__read_nocancel (file_fd, &last_entry, sizeof (struct utmp)) + != sizeof (struct utmp)) { - /* Read the next entry. */ - if (__read_nocancel (file_fd, &last_entry, sizeof (struct utmp)) - != sizeof (struct utmp)) - { - __set_errno (ESRCH); - file_offset = -1l; - return -1; - } - file_offset += sizeof (struct utmp); - - if (id->ut_type == last_entry.ut_type) - break; + __set_errno (ESRCH); + file_offset = -1l; + return -1; } - } - else - { - /* Search for the next entry with the specified ID and with type - INIT_PROCESS, LOGIN_PROCESS, USER_PROCESS, or DEAD_PROCESS. */ + file_offset += sizeof (struct utmp); - while (1) - { - /* Read the next entry. */ - if (__read_nocancel (file_fd, &last_entry, sizeof (struct utmp)) - != sizeof (struct utmp)) - { - __set_errno (ESRCH); - file_offset = -1l; - return -1; - } - file_offset += sizeof (struct utmp); - - if (__utmp_equal (&last_entry, id)) - break; - } + if (matches_last_entry (id)) + break; } return 0; @@ -365,13 +353,7 @@ __libc_pututline (const struct utmp *data) /* Find the correct place to insert the data. */ bool found = false; - if (file_offset > 0 - && ((last_entry.ut_type == data->ut_type - && (last_entry.ut_type == RUN_LVL - || last_entry.ut_type == BOOT_TIME - || last_entry.ut_type == OLD_TIME - || last_entry.ut_type == NEW_TIME)) - || __utmp_equal (&last_entry, data))) + if (matches_last_entry (data)) { if (__lseek64 (file_fd, file_offset, SEEK_SET) < 0) { @@ -389,7 +371,7 @@ __libc_pututline (const struct utmp *data) found = false; } else - found = __utmp_equal (&last_entry, data); + found = matches_last_entry (data); } if (!found)