From bd1eaceaa3975bd2a2a34e211cff896affaecadf Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Tue, 9 Jun 2015 20:09:27 +0000 Subject: fix spurious errors from pwd/grp functions when nscd backend is absent for several pwd/grp functions, the only way the caller can distinguish between a successful negative result ("no such user/group") and an internal error is by clearing errno before the call and checking errno afterwards. the nscd backend support code correctly simulated a not-found response on systems where such a backend is not running, but failed to restore errno. this commit also fixed an outdated/incorrect comment. --- src/passwd/nscd_query.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'src/passwd') diff --git a/src/passwd/nscd_query.c b/src/passwd/nscd_query.c index 69a7815e..d38e371b 100644 --- a/src/passwd/nscd_query.c +++ b/src/passwd/nscd_query.c @@ -32,6 +32,7 @@ FILE *__nscd_query(int32_t req, const char *key, int32_t *buf, size_t len, int * }, .msg_iovlen = 2 }; + int errno_save = errno; *swap = 0; retry: @@ -50,11 +51,14 @@ retry: return f; if (connect(fd, (struct sockaddr*)&addr, sizeof(addr)) < 0) { - /* If there isn't a running nscd we return -1 to indicate that - * that is precisely what happened - */ - if (errno == EACCES || errno == ECONNREFUSED || errno == ENOENT) + /* If there isn't a running nscd we simulate a "not found" + * result and the caller is responsible for calling + * fclose on the (unconnected) socket. The value of + * errno must be left unchanged in this case. */ + if (errno == EACCES || errno == ECONNREFUSED || errno == ENOENT) { + errno = errno_save; return f; + } goto error; } -- cgit v1.2.1