Re: cups debugging, continued

[Isaac Dunham <ibid.ag@gmail.com>]

On Sun, Jun 29, 2014 at 10:03:11PM -0400, Rich Felker wrote:
> On Sun, Jun 29, 2014 at 06:28:31PM -0700, Isaac Dunham wrote:
> > On Sun, Jun 29, 2014 at 05:12:01PM -0700, Isaac Dunham wrote:
> > > Now I hit the next issue: the 'lpd' backend reports 
> > > 'Unable to reserve port: Invalid argument'
> > > And I need to figure out what's causing this--or rather, what the solution is.
> > > Right now, I'm stuck (lpd is the main way to access it, and it isn't working).
> > OK, now we're in cups-1.7.3/backend/lpd.c:
> > 
> > ....the problem is a local implementation of rresvport_af(), trying to reserve
> > a port but failing.
> > 
> > And strace -p `pidof lpd` says this:
> > Process 16113 attached
> > restart_syscall(<... resuming interrupted call ...>) = 0
> > geteuid32()                             = 0
> > socket(PF_INET, SOCK_STREAM, IPPROTO_IP) = 7
> > bind(7, {sa_family=AF_INET, sin_port=htons(905), sin_addr=inet_addr("0.0.0.0")}, 256) = -1 EINVAL (Invalid argument)
> 
> Where did the value of 256 for socklen_t come from? That's almost
> surely the cause of the EINVAL. sockaddr_in should have a length of
> 16, not 256.
Apparently this:
    if (!bind(fd, (struct sockaddr *)&addr, sizeof(addr)))
          return (fd);

addr is of type http_addr_t, defined in cups/http.h thus:
typedef union _http_addr_u              /**** Socket address union, which
                                         **** makes using IPv6 and other
					 **** address types easier and
					 **** more portable. @since CUPS 1.2/OS X 10.5@                                  ****/
										{
  struct sockaddr       addr;           /* Base structure for family value */
  struct sockaddr_in    ipv4;           /* IPv4 address */
#ifdef AF_INET6
  struct sockaddr_in6   ipv6;           /* IPv6 address */
#endif /* AF_INET6 */
#ifdef AF_LOCAL
  struct sockaddr_un    un;             /* Domain socket file */
#endif /* AF_LOCAL */
  char                  pad[256];       /* Padding to ensure binary compatibility */
} http_addr_t;

I'm not sure how to handle this.

Thanks,
Isaac Dunham