scp.c

OpenSSH 是 SSH （Secure SHell） 协议的免费开源实现。它用安全、加密的网络连接工具代替了 telnet、ftp、 rlogin、rsh 和 rcp 工具。OpenSSH 支持

		for (haderr = i = 0; i < stb.st_size; i += bp->cnt) {
			amt = bp->cnt;
			if (i + amt > stb.st_size)
				amt = stb.st_size - i;
			if (!haderr) {
				result = atomicio(read, fd, bp->buf, amt);
				if (result != amt)
					haderr = result >= 0 ? EIO : errno;
			}
			if (haderr)
				(void) atomicio(vwrite, remout, bp->buf, amt);
			else {
				result = atomicio(vwrite, remout, bp->buf, amt);
				if (result != amt)
					haderr = result >= 0 ? EIO : errno;
				statbytes += result;
			}
			if (limit_rate)
				bwlimit(amt);
		}
		if (showprogress)
			stop_progress_meter();

		if (close(fd) < 0 && !haderr)
			haderr = errno;
		if (!haderr)
			(void) atomicio(vwrite, remout, "", 1);
		else
			run_err("%s: %s", name, strerror(haderr));
		(void) response();
	}
}

void
rsource(char *name, struct stat *statp)
{
	DIR *dirp;
	struct dirent *dp;
	char *last, *vect[1], path[1100];

	if (!(dirp = opendir(name))) {
		run_err("%s: %s", name, strerror(errno));
		return;
	}
	last = strrchr(name, '/');
	if (last == 0)
		last = name;
	else
		last++;
	if (pflag) {
		(void) snprintf(path, sizeof(path), "T%lu 0 %lu 0\n",
		    (u_long) statp->st_mtime,
		    (u_long) statp->st_atime);
		(void) atomicio(vwrite, remout, path, strlen(path));
		if (response() < 0) {
			closedir(dirp);
			return;
		}
	}
	(void) snprintf(path, sizeof path, "D%04o %d %.1024s\n",
	    (u_int) (statp->st_mode & FILEMODEMASK), 0, last);
	if (verbose_mode)
		fprintf(stderr, "Entering directory: %s", path);
	(void) atomicio(vwrite, remout, path, strlen(path));
	if (response() < 0) {
		closedir(dirp);
		return;
	}
	while ((dp = readdir(dirp)) != NULL) {
		if (dp->d_ino == 0)
			continue;
		if (!strcmp(dp->d_name, ".") || !strcmp(dp->d_name, ".."))
			continue;
		if (strlen(name) + 1 + strlen(dp->d_name) >= sizeof(path) - 1) {
			run_err("%s/%s: name too long", name, dp->d_name);
			continue;
		}
		(void) snprintf(path, sizeof path, "%s/%s", name, dp->d_name);
		vect[0] = path;
		source(1, vect);
	}
	(void) closedir(dirp);
	(void) atomicio(vwrite, remout, "E\n", 2);
	(void) response();
}

void
bwlimit(int amount)
{
	static struct timeval bwstart, bwend;
	static int lamt, thresh = 16384;
	u_int64_t waitlen;
	struct timespec ts, rm;

	if (!timerisset(&bwstart)) {
		gettimeofday(&bwstart, NULL);
		return;
	}

	lamt += amount;
	if (lamt < thresh)
		return;

	gettimeofday(&bwend, NULL);
	timersub(&bwend, &bwstart, &bwend);
	if (!timerisset(&bwend))
		return;

	lamt *= 8;
	waitlen = (double)1000000L * lamt / limit_rate;

	bwstart.tv_sec = waitlen / 1000000L;
	bwstart.tv_usec = waitlen % 1000000L;

	if (timercmp(&bwstart, &bwend, >)) {
		timersub(&bwstart, &bwend, &bwend);

		/* Adjust the wait time */
		if (bwend.tv_sec) {
			thresh /= 2;
			if (thresh < 2048)
				thresh = 2048;
		} else if (bwend.tv_usec < 100) {
			thresh *= 2;
			if (thresh > 32768)
				thresh = 32768;
		}

		TIMEVAL_TO_TIMESPEC(&bwend, &ts);
		while (nanosleep(&ts, &rm) == -1) {
			if (errno != EINTR)
				break;
			ts = rm;
		}
	}

	lamt = 0;
	gettimeofday(&bwstart, NULL);
}

void
sink(int argc, char **argv)
{
	static BUF buffer;
	struct stat stb;
	enum {
		YES, NO, DISPLAYED
	} wrerr;
	BUF *bp;
	off_t i, j;
	int amt, count, exists, first, mask, mode, ofd, omode;
	off_t size, statbytes;
	int setimes, targisdir, wrerrno = 0;
	char ch, *cp, *np, *targ, *why, *vect[1], buf[2048];
	struct timeval tv[2];

#define	atime	tv[0]
#define	mtime	tv[1]
#define	SCREWUP(str)	{ why = str; goto screwup; }

	setimes = targisdir = 0;
	mask = umask(0);
	if (!pflag)
		(void) umask(mask);
	if (argc != 1) {
		run_err("ambiguous target");
		exit(1);
	}
	targ = *argv;
	if (targetshouldbedirectory)
		verifydir(targ);

	(void) atomicio(vwrite, remout, "", 1);
	if (stat(targ, &stb) == 0 && S_ISDIR(stb.st_mode))
		targisdir = 1;
	for (first = 1;; first = 0) {
		cp = buf;
		if (atomicio(read, remin, cp, 1) <= 0)
			return;
		if (*cp++ == '\n')
			SCREWUP("unexpected <newline>");
		do {
			if (atomicio(read, remin, &ch, sizeof(ch)) != sizeof(ch))
				SCREWUP("lost connection");
			*cp++ = ch;
		} while (cp < &buf[sizeof(buf) - 1] && ch != '\n');
		*cp = 0;
		if (verbose_mode)
			fprintf(stderr, "Sink: %s", buf);

		if (buf[0] == '\01' || buf[0] == '\02') {
			if (iamremote == 0)
				(void) atomicio(vwrite, STDERR_FILENO,
				    buf + 1, strlen(buf + 1));
			if (buf[0] == '\02')
				exit(1);
			++errs;
			continue;
		}
		if (buf[0] == 'E') {
			(void) atomicio(vwrite, remout, "", 1);
			return;
		}
		if (ch == '\n')
			*--cp = 0;

		cp = buf;
		if (*cp == 'T') {
			setimes++;
			cp++;
			mtime.tv_sec = strtol(cp, &cp, 10);
			if (!cp || *cp++ != ' ')
				SCREWUP("mtime.sec not delimited");
			mtime.tv_usec = strtol(cp, &cp, 10);
			if (!cp || *cp++ != ' ')
				SCREWUP("mtime.usec not delimited");
			atime.tv_sec = strtol(cp, &cp, 10);
			if (!cp || *cp++ != ' ')
				SCREWUP("atime.sec not delimited");
			atime.tv_usec = strtol(cp, &cp, 10);
			if (!cp || *cp++ != '\0')
				SCREWUP("atime.usec not delimited");
			(void) atomicio(vwrite, remout, "", 1);
			continue;
		}
		if (*cp != 'C' && *cp != 'D') {
			/*
			 * Check for the case "rcp remote:foo\* local:bar".
			 * In this case, the line "No match." can be returned
			 * by the shell before the rcp command on the remote is
			 * executed so the ^Aerror_message convention isn't
			 * followed.
			 */
			if (first) {
				run_err("%s", cp);
				exit(1);
			}
			SCREWUP("expected control record");
		}
		mode = 0;
		for (++cp; cp < buf + 5; cp++) {
			if (*cp < '0' || *cp > '7')
				SCREWUP("bad mode");
			mode = (mode << 3) | (*cp - '0');
		}
		if (*cp++ != ' ')
			SCREWUP("mode not delimited");

		for (size = 0; isdigit(*cp);)
			size = size * 10 + (*cp++ - '0');
		if (*cp++ != ' ')
			SCREWUP("size not delimited");
		if ((strchr(cp, '/') != NULL) || (strcmp(cp, "..") == 0)) {
			run_err("error: unexpected filename: %s", cp);
			exit(1);
		}
		if (targisdir) {
			static char *namebuf;
			static int cursize;
			size_t need;

			need = strlen(targ) + strlen(cp) + 250;
			if (need > cursize) {
				if (namebuf)
					xfree(namebuf);
				namebuf = xmalloc(need);
				cursize = need;
			}
			(void) snprintf(namebuf, need, "%s%s%s", targ,
			    strcmp(targ, "/") ? "/" : "", cp);
			np = namebuf;
		} else
			np = targ;
		curfile = cp;
		exists = stat(np, &stb) == 0;
		if (buf[0] == 'D') {
			int mod_flag = pflag;
			if (!iamrecursive)
				SCREWUP("received directory without -r");
			if (exists) {
				if (!S_ISDIR(stb.st_mode)) {
					errno = ENOTDIR;
					goto bad;
				}
				if (pflag)
					(void) chmod(np, mode);
			} else {
				/* Handle copying from a read-only
				   directory */
				mod_flag = 1;
				if (mkdir(np, mode | S_IRWXU) < 0)
					goto bad;
			}
			vect[0] = xstrdup(np);
			sink(1, vect);
			if (setimes) {
				setimes = 0;
				if (utimes(vect[0], tv) < 0)
					run_err("%s: set times: %s",
					    vect[0], strerror(errno));
			}
			if (mod_flag)
				(void) chmod(vect[0], mode);
			if (vect[0])
				xfree(vect[0]);
			continue;
		}
		omode = mode;
		mode |= S_IWRITE;
		if ((ofd = open(np, O_WRONLY|O_CREAT, mode)) < 0) {
bad:			run_err("%s: %s", np, strerror(errno));
			continue;
		}
		(void) atomicio(vwrite, remout, "", 1);
		if ((bp = allocbuf(&buffer, ofd, 4096)) == NULL) {
			(void) close(ofd);
			continue;
		}
		cp = bp->buf;
		wrerr = NO;

		statbytes = 0;
		if (showprogress)
			start_progress_meter(curfile, size, &statbytes);
		for (count = i = 0; i < size; i += 4096) {
			amt = 4096;
			if (i + amt > size)
				amt = size - i;
			count += amt;
			do {
				j = atomicio(read, remin, cp, amt);
				if (j <= 0) {
					run_err("%s", j ? strerror(errno) :
					    "dropped connection");
					exit(1);
				}
				amt -= j;
				cp += j;
				statbytes += j;
			} while (amt > 0);

			if (limit_rate)
				bwlimit(4096);

			if (count == bp->cnt) {
				/* Keep reading so we stay sync'd up. */
				if (wrerr == NO) {
					j = atomicio(vwrite, ofd, bp->buf, count);
					if (j != count) {
						wrerr = YES;
						wrerrno = j >= 0 ? EIO : errno;
					}
				}
				count = 0;
				cp = bp->buf;
			}
		}
		if (showprogress)
			stop_progress_meter();
		if (count != 0 && wrerr == NO &&
		    (j = atomicio(vwrite, ofd, bp->buf, count)) != count) {
			wrerr = YES;
			wrerrno = j >= 0 ? EIO : errno;
		}
		if (wrerr == NO && ftruncate(ofd, size) != 0) {
			run_err("%s: truncate: %s", np, strerror(errno));
			wrerr = DISPLAYED;
		}
		if (pflag) {
			if (exists || omode != mode)
#ifdef HAVE_FCHMOD
				if (fchmod(ofd, omode)) {
#else /* HAVE_FCHMOD */
				if (chmod(np, omode)) {
#endif /* HAVE_FCHMOD */
					run_err("%s: set mode: %s",
					    np, strerror(errno));
					wrerr = DISPLAYED;
				}
		} else {
			if (!exists && omode != mode)
#ifdef HAVE_FCHMOD
				if (fchmod(ofd, omode & ~mask)) {
#else /* HAVE_FCHMOD */
				if (chmod(np, omode & ~mask)) {
#endif /* HAVE_FCHMOD */
					run_err("%s: set mode: %s",
					    np, strerror(errno));
					wrerr = DISPLAYED;
				}
		}
		if (close(ofd) == -1) {
			wrerr = YES;
			wrerrno = errno;
		}
		(void) response();
		if (setimes && wrerr == NO) {
			setimes = 0;
			if (utimes(np, tv) < 0) {
				run_err("%s: set times: %s",
				    np, strerror(errno));
				wrerr = DISPLAYED;
			}
		}
		switch (wrerr) {
		case YES:
			run_err("%s: %s", np, strerror(wrerrno));
			break;
		case NO:
			(void) atomicio(vwrite, remout, "", 1);
			break;
		case DISPLAYED:
			break;
		}
	}
screwup:
	run_err("protocol error: %s", why);
	exit(1);
}

int
response(void)
{
	char ch, *cp, resp, rbuf[2048];

	if (atomicio(read, remin, &resp, sizeof(resp)) != sizeof(resp))
		lostconn(0);

	cp = rbuf;
	switch (resp) {
	case 0:		/* ok */
		return (0);
	default:
		*cp++ = resp;
		/* FALLTHROUGH */
	case 1:		/* error, followed by error msg */
	case 2:		/* fatal error, "" */
		do {
			if (atomicio(read, remin, &ch, sizeof(ch)) != sizeof(ch))
				lostconn(0);
			*cp++ = ch;
		} while (cp < &rbuf[sizeof(rbuf) - 1] && ch != '\n');

		if (!iamremote)
			(void) atomicio(vwrite, STDERR_FILENO, rbuf, cp - rbuf);
		++errs;
		if (resp == 1)
			return (-1);
		exit(1);
	}
	/* NOTREACHED */
}

void
usage(void)
{
	(void) fprintf(stderr,
	    "usage: scp [-1246BCpqrv] [-c cipher] [-F ssh_config] [-i identity_file]\n"
	    "           [-l limit] [-o ssh_option] [-P port] [-S program]\n"
	    "           [[user@]host1:]file1 [...] [[user@]host2:]file2\n");
	exit(1);
}

void
run_err(const char *fmt,...)
{
	static FILE *fp;
	va_list ap;

	++errs;
	if (fp == NULL && !(fp = fdopen(remout, "w")))
		return;
	(void) fprintf(fp, "%c", 0x01);
	(void) fprintf(fp, "scp: ");
	va_start(ap, fmt);
	(void) vfprintf(fp, fmt, ap);
	va_end(ap);
	(void) fprintf(fp, "\n");
	(void) fflush(fp);

	if (!iamremote) {
		va_start(ap, fmt);
		vfprintf(stderr, fmt, ap);
		va_end(ap);
		fprintf(stderr, "\n");
	}
}

void
verifydir(char *cp)
{
	struct stat stb;

	if (!stat(cp, &stb)) {
		if (S_ISDIR(stb.st_mode))
			return;
		errno = ENOTDIR;
	}
	run_err("%s: %s", cp, strerror(errno));
	exit(1);
}

int
okname(char *cp0)
{
	int c;
	char *cp;

	cp = cp0;
	do {
		c = (int)*cp;
		if (c & 0200)
			goto bad;
		if (!isalpha(c) && !isdigit(c)) {
			switch (c) {
			case '\'':
			case '"':
			case '`':
			case ' ':
			case '#':
				goto bad;
			default:
				break;
			}
		}
	} while (*++cp);
	return (1);

bad:	fprintf(stderr, "%s: invalid user name\n", cp0);
	return (0);
}

BUF *
allocbuf(BUF *bp, int fd, int blksize)
{
	size_t size;
#ifdef HAVE_STRUCT_STAT_ST_BLKSIZE
	struct stat stb;

	if (fstat(fd, &stb) < 0) {
		run_err("fstat: %s", strerror(errno));
		return (0);
	}
	size = roundup(stb.st_blksize, blksize);
	if (size == 0)
		size = blksize;
#else /* HAVE_STRUCT_STAT_ST_BLKSIZE */
	size = blksize;
#endif /* HAVE_STRUCT_STAT_ST_BLKSIZE */
	if (bp->cnt >= size)
		return (bp);
	if (bp->buf == NULL)
		bp->buf = xmalloc(size);
	else
		bp->buf = xrealloc(bp->buf, size);
	memset(bp->buf, 0, size);
	bp->cnt = size;
	return (bp);
}

void
lostconn(int signo)
{
	if (!iamremote)
		write(STDERR_FILENO, "lost connection\n", 16);
	if (signo)
		_exit(1);
	else
		exit(1);
}