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2010-06-02 Andreas Schwab <schwab@redhat.com> * sysdeps/unix/sysv/linux/getlogin_r.c (__getlogin_r_loginuid): Fix error handling. Properly resize buffer. Don't set errno. (getlogin_r): Only use fallback if __getlogin_r_loginuid returns -1. --- sysdeps/unix/sysv/linux/getlogin_r.c | 63 ++++++++++++++++++++-------------- 1 files changed, 37 insertions(+), 26 deletions(-) diff --git a/sysdeps/unix/sysv/linux/getlogin_r.c b/sysdeps/unix/sysv/linux/getlogin_r.c index dad2671..404c84d 100644 --- a/sysdeps/unix/sysv/linux/getlogin_r.c +++ b/sysdeps/unix/sysv/linux/getlogin_r.c @@ -27,6 +27,10 @@ static int getlogin_r_fd0 (char *name, size_t namesize); #undef getlogin_r +/* Try to determine login name from /proc/self/loginuid and return 0 + if successful. If /proc/self/loginuid cannot be read return -1. + Otherwise return the error number. */ + int attribute_hidden __getlogin_r_loginuid (name, namesize) @@ -35,7 +39,7 @@ __getlogin_r_loginuid (name, namesize) { int fd = open_not_cancel_2 ("/proc/self/loginuid", O_RDONLY); if (fd == -1) - return 1; + return -1; /* We are reading a 32-bit number. 12 bytes are enough for the text representation. If not, something is wrong. */ @@ -51,46 +55,50 @@ __getlogin_r_loginuid (name, namesize) || (uidbuf[n] = '\0', uid = strtoul (uidbuf, &endp, 10), endp == uidbuf || *endp != '\0')) - return 1; + return -1; size_t buflen = 1024; char *buf = alloca (buflen); bool use_malloc = false; struct passwd pwd; struct passwd *tpwd; - int res; - - while ((res = __getpwuid_r (uid, &pwd, buf, buflen, &tpwd)) != 0) - if (__libc_use_alloca (2 * buflen)) - extend_alloca (buf, buflen, 2 * buflen); - else - { - buflen *= 2; - char *newp = realloc (use_malloc ? buf : NULL, buflen); - if (newp == NULL) - { - fail: - if (use_malloc) - free (buf); - return 1; - } - buf = newp; - use_malloc = true; - } + int result; + + while ((result = __getpwuid_r (uid, &pwd, buf, buflen, &tpwd)) != 0) + { + if (result != ERANGE) + goto out; + if (__libc_use_alloca (2 * buflen)) + buf = extend_alloca (buf, buflen, 2 * buflen); + else + { + buflen *= 2; + char *newp = realloc (use_malloc ? buf : NULL, buflen); + if (newp == NULL) + { + result = ENOMEM; + goto out; + } + buf = newp; + use_malloc = true; + } + } if (tpwd == NULL) - goto fail; + { + result = ENOENT; + goto out; + } - int result = 0; size_t needed = strlen (pwd.pw_name) + 1; if (needed > namesize) { - __set_errno (ERANGE); result = ERANGE; goto out; } memcpy (name, pwd.pw_name, needed); + result = 0; out: if (use_malloc) @@ -109,8 +117,11 @@ getlogin_r (name, namesize) char *name; size_t namesize; { - if (__getlogin_r_loginuid (name, namesize) == 0) - return 0; + int result; + + result = __getlogin_r_loginuid (name, namesize); + if (result >= 0) + return result; return getlogin_r_fd0 (name, namesize); } -- 1.7.1 -- Andreas Schwab, schwab@redhat.com GPG Key fingerprint = D4E8 DBE3 3813 BB5D FA84 5EC7 45C6 250E 6F00 984E "And now for something completely different."
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