From owner-freebsd-audit Thu May 17 22:17:34 2001 Delivered-To: freebsd-audit@freebsd.org Received: from bazooka.unixfreak.org (bazooka.unixfreak.org [63.198.170.138]) by hub.freebsd.org (Postfix) with ESMTP id 5CA8337B423 for ; Thu, 17 May 2001 22:17:27 -0700 (PDT) (envelope-from dima@unixfreak.org) Received: from hornet.unixfreak.org (hornet [63.198.170.140]) by bazooka.unixfreak.org (Postfix) with ESMTP id D1FD83E0B for ; Thu, 17 May 2001 22:17:26 -0700 (PDT) To: audit@freebsd.org Subject: Patch to make snp(4) a module Date: Thu, 17 May 2001 22:17:26 -0700 From: Dima Dorfman Message-Id: <20010518051726.D1FD83E0B@bazooka.unixfreak.org> Sender: owner-freebsd-audit@FreeBSD.ORG Precedence: bulk List-ID: X-Loop: FreeBSD.ORG Please review the attached patch to make snp(4) a module. Right now, two things stop it from being one: it relies on hacks in the tty subsystem which are compiled in just for it, and there is no kld code in it. The hacks in the tty subsystem look like this: #ifdef DEV_SNP if (ISSET(tp->t_state, TS_SNOOP) && tp->t_sc != NULL) snpin((struct snoop *)tp->t_sc, cp, cc); #endif The patch solves this problem by using line disciplines to get the information it needs. I don't know whether this is abuse or how bad it is, but I sent this to -hackers a little while ago and no one responsed (which means it's not interesting enough to say anything but not ugly enough to warrant a bikeshed, either). The second problem of not having kld code is solved in the obvious manner (by adding the code). Please review. Thanks in advance, Dima Dorfman dima@unixfreak.org Index: kern/tty_snoop.c =================================================================== RCS file: /st/src/FreeBSD/src/sys/kern/tty_snoop.c,v retrieving revision 1.53 diff -u -r1.53 tty_snoop.c --- kern/tty_snoop.c 2001/04/17 20:53:11 1.53 +++ kern/tty_snoop.c 2001/05/15 04:15:51 @@ -12,10 +12,9 @@ * * Snoop stuff. * - * $FreeBSD: src/sys/kern/tty_snoop.c,v 1.53 2001/04/17 20:53:11 dd Exp $ + * $FreeBSD$ */ -#include "opt_compat.h" #include #include #include @@ -29,6 +28,7 @@ #include #include #include +#include static d_open_t snpopen; static d_close_t snpclose; @@ -61,9 +61,63 @@ static MALLOC_DEFINE(M_SNP, "snp", "Snoop device data"); +#define ttytosnp(t) (struct snoop *)(t)->t_sc static struct tty *snpdevtotty __P((dev_t dev)); static int snp_detach __P((struct snoop *snp)); +/* + * The number of the "snoop" line discipline. This gets determined at + * module load time. + */ +static int mylinedisc; + +static int +dsnwrite(struct tty *tp, struct uio *uio, int flag) +{ + struct snoop *snp = ttytosnp(tp); + int error = 0; + char ibuf[1024]; + int ilen; + struct iovec iov; + struct uio uio2; + + while (uio->uio_resid) { + ilen = MIN(sizeof(ibuf), uio->uio_resid); + error = uiomove(ibuf, ilen, uio); + if (error) + break; + snpin(snp, ibuf, ilen); + /* Hackish, but I think it's the least of all evils. */ + iov.iov_base = ibuf; + iov.iov_len = ilen; + uio2.uio_iov = &iov; + uio2.uio_iovcnt = 1; + uio2.uio_offset = 0; + uio2.uio_resid = ilen; + uio2.uio_segflg = UIO_SYSSPACE; + uio2.uio_rw = UIO_WRITE; + uio2.uio_procp = uio->uio_procp; + error = ttwrite(tp, &uio2, flag); + if (error) + break; + } + return (error); +} + +/* + * XXX should there be a global version of this? + */ +static int +l_nullioctl(struct tty *tp, u_long cmd, char *data, int flags, struct proc *p) +{ + + return (ENOIOCTL); +} + +static struct linesw snpdisc = { + ttyopen, ttylclose, ttread, dsnwrite, + l_nullioctl, ttyinput, ttstart, ttymodem }; + static struct tty * snpdevtotty (dev) dev_t dev; @@ -98,7 +152,7 @@ tp = snp->snp_tty; if ((tp->t_sc == snp) && (tp->t_state & TS_SNOOP) && - (tp->t_line == OTTYDISC || tp->t_line == NTTYDISC)) + tp->t_line == mylinedisc) goto tty_input; printf("Snoop: attempt to write to bad tty.\n"); @@ -334,9 +388,10 @@ tp = snp->snp_tty; if (tp && (tp->t_sc == snp) && (tp->t_state & TS_SNOOP) && - (tp->t_line == OTTYDISC || tp->t_line == NTTYDISC)) { + tp->t_line == mylinedisc) { tp->t_sc = NULL; tp->t_state &= ~TS_SNOOP; + tp->t_line = snp->snp_olddisc; } else printf("Snoop: bad attached tty data.\n"); @@ -409,12 +464,6 @@ if (!tp) return (EINVAL); - if ((tp->t_sc != (caddr_t)snp) && (tp->t_state & TS_SNOOP)) - return (EBUSY); - - if ((tp->t_line != OTTYDISC) && (tp->t_line != NTTYDISC)) - return (EBUSY); - s = spltty(); if (snp->snp_target == NODEV) { @@ -425,6 +474,8 @@ tp->t_sc = (caddr_t)snp; tp->t_state |= TS_SNOOP; + snp->snp_olddisc = tp->t_line; + tp->t_line = mylinedisc; snp->snp_tty = tp; snp->snp_target = tdev; @@ -503,8 +554,6 @@ return (revents); } -static void snp_drvinit __P((void *unused)); - static void snp_clone(void *arg, char *name, int namelen, dev_t *dev) { @@ -519,13 +568,31 @@ return; } -static void -snp_drvinit(unused) - void *unused; +static int +snp_modevent(module_t mod, int type, void *data) { + static eventhandler_tag eh_tag = NULL; - EVENTHANDLER_REGISTER(dev_clone, snp_clone, 0, 1000); - cdevsw_add(&snp_cdevsw); + switch (type) { + case MOD_LOAD: + eh_tag = EVENTHANDLER_REGISTER(dev_clone, snp_clone, 0, 1000); + mylinedisc = ldisc_register(LDISC_LOAD, &snpdisc); + cdevsw_add(&snp_cdevsw); + break; + case MOD_UNLOAD: + EVENTHANDLER_DEREGISTER(dev_clone, eh_tag); + ldisc_deregister(mylinedisc); + cdevsw_remove(&snp_cdevsw); + break; + default: + break; + } + return 0; } -SYSINIT(snpdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,snp_drvinit,NULL) +static moduledata_t snp_mod = { + "snp", + snp_modevent, + NULL +}; +DECLARE_MODULE(snp, snp_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE+CDEV_MAJOR); Index: sys/snoop.h =================================================================== RCS file: /st/src/FreeBSD/src/sys/sys/snoop.h,v retrieving revision 1.14 diff -u -r1.14 snoop.h --- sys/snoop.h 1999/12/29 04:24:47 1.14 +++ sys/snoop.h 2001/05/15 04:15:51 @@ -54,6 +54,7 @@ #define SNOOP_OFLOW 0x0010 #define SNOOP_DOWN 0x0020 struct selinfo snp_sel; /* Selection info */ + int snp_olddisc; /* Old line discipline */ }; /* XXX several wrong storage classes and types here. */ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-audit" in the body of the message