The Tor Browser: other-licenses/android/ev_streams.c@97036ab72558 (annotated)

other-licenses/android/ev_streams.c@97036ab72558 (annotated)

other-licenses/android/ev_streams.c

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /*	$NetBSD: ev_streams.c,v 1.2 2004/05/20 19:52:31 christos Exp $	*/
 /*
  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
  * Copyright (c) 1996-1999 by Internet Software Consortium
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies.
  *
  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 /* ev_streams.c - implement asynch stream file IO for the eventlib
  * vix 04mar96 [initial]
  */
 /*
  * This version of this file is derived from Android 2.3 "Gingerbread",
  * which contains uncredited changes by Android/Google developers.  It has
  * been modified in 2011 for use in the Android build of Mozilla Firefox by
  * Mozilla contributors (including Michael Edwards <m.k.edwards@gmail.com>,
  * and Steve Workman <sjhworkman@gmail.com>).
  * These changes are offered under the same license as the original NetBSD
  * file, whose copyright and license are unchanged above.
  */
 #define ANDROID_CHANGES 1
 #define MOZILLA_NECKO_EXCLUDE_CODE 1
 #include <sys/cdefs.h>
 #if !defined(LINT) && !defined(CODECENTER) && !defined(lint)
 #ifdef notdef
 static const char rcsid[] = "Id: ev_streams.c,v 1.2.206.2 2004/03/17 00:29:51 marka Exp";
 #else
 __RCSID("$NetBSD: ev_streams.c,v 1.2 2004/05/20 19:52:31 christos Exp $");
 #endif
 #endif
 #include <sys/types.h>
 #include <sys/uio.h>
 #include <errno.h>
 #include "eventlib.h"
 #include "eventlib_p.h"
 #ifndef MOZILLA_NECKO_EXCLUDE_CODE
 #ifndef _LIBC
 static int	copyvec(evStream *str, const struct iovec *iov, int iocnt);
 static void	consume(evStream *str, size_t bytes);
 static void	done(evContext opaqueCtx, evStream *str);
 static void	writable(evContext opaqueCtx, void *uap, int fd, int evmask);
 static void	readable(evContext opaqueCtx, void *uap, int fd, int evmask);
 #endif
 #endif
 struct iovec
 evConsIovec(void *buf, size_t cnt) {
 	struct iovec ret;
 	memset(&ret, 0xf5, sizeof ret);
 	ret.iov_base = buf;
 	ret.iov_len = cnt;
 	return (ret);
 }
 #ifndef MOZILLA_NECKO_EXCLUDE_CODE
 #ifndef _LIBC
 int
 evWrite(evContext opaqueCtx, int fd, const struct iovec *iov, int iocnt,
 	evStreamFunc func, void *uap, evStreamID *id)
 {
 	evContext_p *ctx = opaqueCtx.opaque;
 	evStream *new;
 	int save;
 	OKNEW(new);
 	new->func = func;
 	new->uap = uap;
 	new->fd = fd;
 	new->flags = 0;
 	if (evSelectFD(opaqueCtx, fd, EV_WRITE, writable, new, &new->file) < 0)
 		goto free;
 	if (copyvec(new, iov, iocnt) < 0)
 		goto free;
 	new->prevDone = NULL;
 	new->nextDone = NULL;
 	if (ctx->streams != NULL)
 		ctx->streams->prev = new;
 	new->prev = NULL;
 	new->next = ctx->streams;
 	ctx->streams = new;
 	if (id != NULL)
 		id->opaque = new;
 	return (0);
  free:
 	save = errno;
 	FREE(new);
 	errno = save;
 	return (-1);
 }
 int
 evRead(evContext opaqueCtx, int fd, const struct iovec *iov, int iocnt,
        evStreamFunc func, void *uap, evStreamID *id)
 {
 	evContext_p *ctx = opaqueCtx.opaque;
 	evStream *new;
 	int save;
 	OKNEW(new);
 	new->func = func;
 	new->uap = uap;
 	new->fd = fd;
 	new->flags = 0;
 	if (evSelectFD(opaqueCtx, fd, EV_READ, readable, new, &new->file) < 0)
 		goto free;
 	if (copyvec(new, iov, iocnt) < 0)
 		goto free;
 	new->prevDone = NULL;
 	new->nextDone = NULL;
 	if (ctx->streams != NULL)
 		ctx->streams->prev = new;
 	new->prev = NULL;
 	new->next = ctx->streams;
 	ctx->streams = new;
 	if (id)
 		id->opaque = new;
 	return (0);
  free:
 	save = errno;
 	FREE(new);
 	errno = save;
 	return (-1);
 }
 int
 evTimeRW(evContext opaqueCtx, evStreamID id, evTimerID timer) /*ARGSUSED*/ {
 	evStream *str = id.opaque;
 	UNUSED(opaqueCtx);
 	str->timer = timer;
 	str->flags |= EV_STR_TIMEROK;
 	return (0);
 }
 int
 evUntimeRW(evContext opaqueCtx, evStreamID id) /*ARGSUSED*/ {
 	evStream *str = id.opaque;
 	UNUSED(opaqueCtx);
 	str->flags &= ~EV_STR_TIMEROK;
 	return (0);
 }
 int
 evCancelRW(evContext opaqueCtx, evStreamID id) {
 	evContext_p *ctx = opaqueCtx.opaque;
 	evStream *old = id.opaque;
 	/*
 	 * The streams list is doubly threaded.  First, there's ctx->streams
 	 * that's used by evDestroy() to find and cancel all streams.  Second,
 	 * there's ctx->strDone (head) and ctx->strLast (tail) which thread
 	 * through the potentially smaller number of "IO completed" streams,
 	 * used in evGetNext() to avoid scanning the entire list.
 	 */
 	/* Unlink from ctx->streams. */
 	if (old->prev != NULL)
 		old->prev->next = old->next;
 	else
 		ctx->streams = old->next;
 	if (old->next != NULL)
 		old->next->prev = old->prev;
 	/*
 	 * If 'old' is on the ctx->strDone list, remove it.  Update
 	 * ctx->strLast if necessary.
 	 */
 	if (old->prevDone == NULL && old->nextDone == NULL) {
 		/*
 		 * Either 'old' is the only item on the done list, or it's
 		 * not on the done list.  If the former, then we unlink it
 		 * from the list.  If the latter, we leave the list alone.
 		 */
 		if (ctx->strDone == old) {
 			ctx->strDone = NULL;
 			ctx->strLast = NULL;
 		}
 	} else {
 		if (old->prevDone != NULL)
 			old->prevDone->nextDone = old->nextDone;
 		else
 			ctx->strDone = old->nextDone;
 		if (old->nextDone != NULL)
 			old->nextDone->prevDone = old->prevDone;
 		else
 			ctx->strLast = old->prevDone;
 	}
 	/* Deallocate the stream. */
 	if (old->file.opaque)
 		evDeselectFD(opaqueCtx, old->file);
 	memput(old->iovOrig, sizeof (struct iovec) * old->iovOrigCount);
 	FREE(old);
 	return (0);
 }
 /* Copy a scatter/gather vector and initialize a stream handler's IO. */
 static int
 copyvec(evStream *str, const struct iovec *iov, int iocnt) {
 	int i;
 	str->iovOrig = (struct iovec *)memget(sizeof(struct iovec) * iocnt);
 	if (str->iovOrig == NULL) {
 		errno = ENOMEM;
 		return (-1);
 	}
 	str->ioTotal = 0;
 	for (i = 0; i < iocnt; i++) {
 		str->iovOrig[i] = iov[i];
 		str->ioTotal += iov[i].iov_len;
 	}
 	str->iovOrigCount = iocnt;
 	str->iovCur = str->iovOrig;
 	str->iovCurCount = str->iovOrigCount;
 	str->ioDone = 0;
 	return (0);
 }
 /* Pull off or truncate lead iovec(s). */
 static void
 consume(evStream *str, size_t bytes) {
 	while (bytes > 0U) {
 		if (bytes < (size_t)str->iovCur->iov_len) {
 			str->iovCur->iov_len -= bytes;
 			str->iovCur->iov_base = (void *)
 				((u_char *)str->iovCur->iov_base + bytes);
 			str->ioDone += bytes;
 			bytes = 0;
 		} else {
 			bytes -= str->iovCur->iov_len;
 			str->ioDone += str->iovCur->iov_len;
 			str->iovCur++;
 			str->iovCurCount--;
 		}
 	}
 }
 /* Add a stream to Done list and deselect the FD. */
 static void
 done(evContext opaqueCtx, evStream *str) {
 	evContext_p *ctx = opaqueCtx.opaque;
 	if (ctx->strLast != NULL) {
 		str->prevDone = ctx->strLast;
 		ctx->strLast->nextDone = str;
 		ctx->strLast = str;
 	} else {
 		INSIST(ctx->strDone == NULL);
 		ctx->strDone = ctx->strLast = str;
 	}
 	evDeselectFD(opaqueCtx, str->file);
 	str->file.opaque = NULL;
 	/* evDrop() will call evCancelRW() on us. */
 }
 /* Dribble out some bytes on the stream.  (Called by evDispatch().) */
 static void
 writable(evContext opaqueCtx, void *uap, int fd, int evmask) {
 	evStream *str = uap;
 	int bytes;
 	UNUSED(evmask);
 	bytes = writev(fd, str->iovCur, str->iovCurCount);
 	if (bytes > 0) {
 		if ((str->flags & EV_STR_TIMEROK) != 0)
 			evTouchIdleTimer(opaqueCtx, str->timer);
 		consume(str, bytes);
 	} else {
 		if (bytes < 0 && errno != EINTR) {
 			str->ioDone = -1;
 			str->ioErrno = errno;
 		}
 	}
 	if (str->ioDone == -1 || str->ioDone == str->ioTotal)
 		done(opaqueCtx, str);
 }
 /* Scoop up some bytes from the stream.  (Called by evDispatch().) */
 static void
 readable(evContext opaqueCtx, void *uap, int fd, int evmask) {
 	evStream *str = uap;
 	int bytes;
 	UNUSED(evmask);
 	bytes = readv(fd, str->iovCur, str->iovCurCount);
 	if (bytes > 0) {
 		if ((str->flags & EV_STR_TIMEROK) != 0)
 			evTouchIdleTimer(opaqueCtx, str->timer);
 		consume(str, bytes);
 	} else {
 		if (bytes == 0)
 			str->ioDone = 0;
 		else {
 			if (errno != EINTR) {
 				str->ioDone = -1;
 				str->ioErrno = errno;
 			}
 		}
 	}
 	if (str->ioDone <= 0 || str->ioDone == str->ioTotal)
 		done(opaqueCtx, str);
 }
 #endif
 #endif

The Tor Browser / annotate

other-licenses/android/ev_streams.c@97036ab72558 (annotated)

other-licenses/android/ev_streams.c