From c6a91c92b51a13f204495851cf7a90e55ec16f0a Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Thu, 29 Nov 2012 19:57:17 -0500 Subject: Produce a more useful error message for over-length Unix socket paths. The length of a socket path name is constrained by the size of struct sockaddr_un, and there's not a lot we can do about it since that is a kernel API. However, it would be a good thing if we produced an intelligible error message when the user specifies a socket path that's too long --- and getaddrinfo's standard API is too impoverished to do this in the natural way. So insert explicit tests at the places where we construct a socket path name. Now you'll get an error that makes sense and even tells you what the limit is, rather than something generic like "Non-recoverable failure in name resolution". Per trouble report from Jeremy Drake and a fix idea from Andrew Dunstan. --- src/include/libpq/pqcomm.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'src/include/libpq/pqcomm.h') diff --git a/src/include/libpq/pqcomm.h b/src/include/libpq/pqcomm.h index bd0fa250778..c28ada8b187 100644 --- a/src/include/libpq/pqcomm.h +++ b/src/include/libpq/pqcomm.h @@ -73,6 +73,19 @@ typedef struct DEFAULT_PGSOCKET_DIR, \ (port)) +/* + * The maximum workable length of a socket path is what will fit into + * struct sockaddr_un. This is usually only 100 or so bytes :-(. + * + * For consistency, always pass a MAXPGPATH-sized buffer to UNIXSOCK_PATH(), + * then complain if the resulting string is >= UNIXSOCK_PATH_BUFLEN bytes. + * (Because the standard API for getaddrinfo doesn't allow it to complain in + * a useful way when the socket pathname is too long, we have to test for + * this explicitly, instead of just letting the subroutine return an error.) + */ +#define UNIXSOCK_PATH_BUFLEN sizeof(((struct sockaddr_un *) NULL)->sun_path) + + /* * These manipulate the frontend/backend protocol version number. * -- cgit v1.2.3