After The Chroot(), Calls To Socket() Are Failing. Why?

1.	After The Chroot(), Calls To Socket() Are Failing. Why?
Answer» On systems where sockets are implemented on top of Streams (e.g. all SysV-based systems, presumably including Solaris), the socket() function will actually be opening certain special files in /dev. You will need to create a /dev directory under your fake root and populate it with the required device NODES (only). Your system documentation may or may not specify exactly which device nodes are required; suggested checking the man page for ftpd, which should list the files you need to copy and DEVICES you need to create in the chroot'd environment.) A less-obvious issue with chroot() is if you call syslog(), as many daemons do; syslog() opens (depending on the system) either a UDP socket, a FIFO or a Unix-domain socket. So if you use it after a chroot() call, MAKE sure that you call openlog() before the chroot.

Answer»

On systems where sockets are implemented on top of Streams (e.g. all SysV-based systems, presumably including Solaris), the socket() function will actually be opening certain special files in /dev. You will need to create a /dev directory under your fake root and populate it with the required device NODES (only).
Your system documentation may or may not specify exactly which device nodes are required; suggested checking the man page for ftpd, which should list the files you need to copy and DEVICES you need to create in the chroot'd environment.)
A less-obvious issue with chroot() is if you call syslog(), as many daemons do; syslog() opens (depending on the system) either a UDP socket, a FIFO or a Unix-domain socket. So if you use it after a chroot() call, MAKE sure that you call openlog() before the chroot.

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