Date: Sun, 20 Jan 2002 15:08:56 -0800 (PST) From: Archie Cobbs <archie@dellroad.org> To: Florent Parent <Florent.Parent@viagenie.qc.ca> Cc: freebsd-net@FreeBSD.ORG, julian@elischer.org Subject: Re: netgraph: how to setsockopt on ksocket node ? Message-ID: <200201202308.g0KN8uc09321@arch20m.dellroad.org> In-Reply-To: <135740000.1011562445@blues.viagenie.qc.ca> "from Florent Parent at Jan 20, 2002 04:34:05 pm"
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Florent Parent writes:
> 'struct proc' member in the struct sockopt can be NULL. As per the comment
> in that structure, NULL means that the calling entity is the kernel, not a
> user process (my interpretation):
>
> struct sockopt {
> enum sopt_dir sopt_dir; /* is this a get or a set? */
> int sopt_level; /* second arg of [gs]etsockopt */
> int sopt_name; /* third arg of [gs]etsockopt */
> void *sopt_val; /* fourth arg of [gs]etsockopt */
> size_t sopt_valsize; /* (almost) fifth arg of [gs]etsockopt */
> struct proc *sopt_p; /* calling process or null if kernel */
> };
>
> This doesn't apply to socreate() since it isn't passed a 'struct sockopt'
> as argument. From a quick glance, the socket functions that are concerned
> are sosetopt() and sogetopt().
But socreate() does take a struct proc directly... perhaps
it can be NULL too..?
[ looks at code ... ]
Nope, it doesn't appear that it can...
> int
> socreate(dom, aso, type, proto, p)
> int dom;
> struct socket **aso;
> register int type;
> int proto;
> struct proc *p;
> {
> register struct protosw *prp;
> register struct socket *so;
> register int error;
>
> if (proto)
> prp = pffindproto(dom, proto, type);
> else
> prp = pffindtype(dom, type);
>
> if (prp == 0 || prp->pr_usrreqs->pru_attach == 0)
> return (EPROTONOSUPPORT);
>
> if (p->p_prison && jail_socket_unixiproute_only &&
> prp->pr_domain->dom_family != PF_LOCAL &&
> prp->pr_domain->dom_family != PF_INET &&
> prp->pr_domain->dom_family != PF_ROUTE) {
> return (EPROTONOSUPPORT);
> }
>
> if (prp->pr_type != type)
> return (EPROTOTYPE);
> so = soalloc(p != 0);
> if (so == 0)
> return (ENOBUFS);
>
> TAILQ_INIT(&so->so_incomp);
> TAILQ_INIT(&so->so_comp);
> so->so_type = type;
> so->so_cred = p->p_ucred;
> crhold(so->so_cred);
> so->so_proto = prp;
> error = (*prp->pr_usrreqs->pru_attach)(so, proto, p);
> if (error) {
> so->so_state |= SS_NOFDREF;
> sofree(so);
> return (error);
> }
> *aso = so;
> return (0);
> }
But it's interesting the soalloc() is called with 'p != 0'
as an argument. p is never 0 or else you would have already
panic'd... you'd panic later on, too, referencing 'p->p_ucred'.
-Archie
__________________________________________________________________________
Archie Cobbs * Packet Design * http://www.packetdesign.com
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