rlogin.c

操作系统源代码

		}
		completed_1(result, errno);
		return;
	}
	completed_1(offset, 0);
}

static void
restart_rd_rem()
{
	size_t offset;
	int result, error;

	assert(!inprogress_rd_rem);
	rd_rem_offset= 0;
	offset= 0;
	while (offset < RD_REM_BUFSIZE)
	{
		result= read(rem, rd_rem_buf+offset, RD_REM_BUFSIZE-offset);
		if (result > 0)
		{
			offset += result;
			assert(offset <= RD_REM_BUFSIZE);
			continue;
		}
		error= errno;

		if (offset != 0)
			completed_rd_rem(offset, 0);
		rd_rem_offset= offset;
		if (result == -1 && error == EINPROGRESS)
		{
			inprogress_rd_rem= 1;
			return;
		}
		completed_rd_rem(result, error);
		return;
	}
	completed_rd_rem(offset, 0);
}

static void
restart_wr_rem()
{
	size_t offset;
	int result, error;

	assert(!inprogress_wr_rem);

	if (extra_wr_rem_new != NULL && extra_wr_rem == NULL)
	{
		extra_wr_rem= extra_wr_rem_new;
		extra_wr_rem_size= extra_wr_rem_new_size;
		extra_wr_rem_offset= 0;
		extra_wr_rem_new= NULL;
		extra_wr_rem_new_size= 0;
	}
	if (extra_wr_rem != NULL)
	{
		offset= 0;
		while (offset < extra_wr_rem_size)
		{
			result= write(rem, 
				extra_wr_rem+extra_wr_rem_offset+offset, 
						extra_wr_rem_size-offset);
			if (result > 0)
			{
				assert (result <= extra_wr_rem_size-offset);
				offset += result;
				continue;
			}
			error= errno;
			if (offset != 0)
				completed_wr_rem(offset, 0);

			if (result == -1 && errno == EINPROGRESS)
			{
				inprogress_wr_rem= 1;
				return;
			}
			completed_wr_rem(result, errno);
			return;
		}
		completed_wr_rem(offset, 0);
	}
	if (wr_rem_size == 0)
		return;

	offset= 0;
	while (offset < wr_rem_size)
	{
		result= write(rem, rd_0_buf+wr_rem_offset+offset, 
							wr_rem_size-offset);
		if (result > 0)
		{
			assert (result <= wr_rem_size-offset);
			offset += result;
			continue;
		}
		error= errno;
		if (offset != 0)
			completed_wr_rem(offset, 0);

		if (result == -1 && errno == EINPROGRESS)
		{
			inprogress_wr_rem= 1;
			return;
		}
		completed_wr_rem(result, errno);
		return;
	}
	completed_wr_rem(offset, 0);
}

static void
completed_0(result, error)
	int result;
	int error;
{
	static int bol= 0, local= 0;

	char *iptr, *optr;
	int i;
	u_char c;

	inprogress_0= 0;

	if (result > 0)
	{
		assert(rd_0_offset > 0);
		wr_rem_offset= 1;

		iptr= rd_0_buf+rd_0_offset;
		optr= rd_0_buf+wr_rem_offset;
		for (i= 0; i<result; iptr++, i++)
		{
			c= *iptr;
			if (bol)
			{
				bol= 0;
				if (!noescape && c == escapechar)
				{
					local= 1;
					continue;
				}
			}
			else if (local)
			{
				local= 0;
				if (c == '.' || (c != _POSIX_VDISABLE &&
					c == defattr.c_cc[VEOF]))
				{
					echo(c);
					finish();
					/* NOTREACHED */
				}
				if (c == '!')
				{
					subshell();
					continue;
				}
				if (c != escapechar)
				{
					if (optr < iptr)
					{
						*(optr++)= escapechar;
					}
					else
					{
						assert(optr == iptr);
						assert(iptr == rd_0_buf+
								rd_0_offset);
						assert(rd_0_offset > 0);
						wr_rem_offset--;
						optr[-1]= escapechar;
					}
				}
			}
			*(optr++)= c;
			bol= (c != _POSIX_VDISABLE) && 
				(c == defattr.c_cc[VKILL] ||
				c == defattr.c_cc[VEOF] ||
				c == defattr.c_cc[VINTR] ||
				c == defattr.c_cc[VSUSP] ||
				c == '\r' || c == '\n');
		}
		wr_rem_size += optr-rd_0_buf-wr_rem_offset;
		if (wr_rem_size != 0)
		{
			more2read_0= 0;
			more2write_rem= 1;
		}
		return;
	}
	fprintf(stderr, "completed_0: %d, %d\n", result, error);
	abort();
}

static void
completed_1(result, error)
	int result;
	int error;
{
	inprogress_1= 0;

	if (result > 0)
	{
		if (extra_1 != NULL)
		{
			assert (result <= extra_1_size);
			extra_1_size -= result;
			extra_1_offset += result;
			if (extra_1_size == 0)
			{
				more2write_1= 0;
				more2read_rem= 1;
				free(extra_1);
				extra_1= NULL;
			}
			return;
		}
		assert (result <= wr_1_size);
		wr_1_size -= result;
		wr_1_offset += result;
		if (wr_1_size == 0)
		{
			more2write_1= 0;
			more2read_rem= 1;
		}
		return;
	}
	fprintf(stderr, "completed_1: %d, %d\n", result, error);
	abort();
}

static void
completed_rd_rem(result, error)
	int result;
	int error;
{
	nwio_tcpopt_t tcpopt;
	char *new_buf;
	size_t keep_size;
	u_char urg_byte;
	int i;

	inprogress_rd_rem= 0;

	if (result > 0)
	{
		if (rd_rem_urg)
		{
#if DEBUG
fprintf(stderr, "\n\r%d urg bytes\n\r", result);
#endif
			if (urg_1_size > MAX_EXTRA_1_NEW_SIZE)
			{
				keep_size= MAX_EXTRA_1_NEW_SIZE/2;
				memmove(urg_1, urg_1+urg_1_size-keep_size, 
					keep_size);
				urg_1_size= keep_size;
			}
			new_buf= realloc(urg_1, urg_1_size+result);
			if (new_buf == NULL)
			{
				fprintf(stderr, 
					"rlogin: warning realloc %d failed\n",
					urg_1_size+result);
				return;
			}
			memcpy(new_buf+urg_1_size, 
				rd_rem_buf+rd_rem_offset, result);
			urg_1= new_buf;
			urg_1_size += result;
			return;
		}
		more2read_rem= 0;
		more2write_1= 1;
		wr_1_size= result;
		wr_1_offset= rd_rem_offset;
		return;
	}
	if (result == -1 && error == EURG)
	{
#if DEBUG
fprintf(stderr, "\n\rEURG\n\r");
#endif
		rd_rem_urg= 1;
		tcpopt.nwto_flags= NWTO_RCV_URG;
		result= ioctl(rem, NWIOSTCPOPT, &tcpopt);
		if (result == -1)
		{
			fprintf(stderr, 
				"rlogin: NWIOSTCPOPT on %d failed (%s)\n",
				rem, strerror(errno));
			exit(1);
		}
		return;
	}
	if (result == -1 && error == ENOURG)
	{
#if DEBUG
fprintf(stderr, "\n\rENOURG\n\r");
#endif
		rd_rem_urg= 0;
		tcpopt.nwto_flags= NWTO_RCV_NOTURG;
		result= ioctl(rem, NWIOSTCPOPT, &tcpopt);
		if (result == -1)
		{
			fprintf(stderr, 
				"rlogin: NWIOSTCPOPT on %d failed (%s)\n",
				rem, strerror(errno));
			exit(1);
		}
		if (urg_1_size != 0)
		{
			urg_byte= urg_1[urg_1_size-1];
			urg_1_size--;
			do_urg(urg_byte);
			if (urg_1_size == 0)
				return;
			if (extra_1_new_size + urg_1_size > MAX_EXTRA_1_NEW_SIZE)
			{
				extra_1_new_size= 0;
				free(extra_1_new);
				extra_1_new= NULL;
			}
			if (extra_1_new_size != 0)
			{
				new_buf= realloc(extra_1_new, 
					extra_1_new_size+urg_1_size);
				if (new_buf == 0)
				{
					extra_1_new_size= 0;
					free(extra_1_new);
					extra_1_new= NULL;
				}
				else
				{
					extra_1_new= new_buf;
					memcpy(extra_1_new+extra_1_new_size,
						urg_1, urg_1_size);
					extra_1_new_size += urg_1_size;
					urg_1_size= 0;
					free(urg_1);
					urg_1= NULL;
				}
			}
			if (extra_1_new_size == 0)
			{
				extra_1_new_size= urg_1_size;
				extra_1_new= urg_1;
				urg_1_size= 0;
				urg_1= NULL;
			}
			more2read_rem= 0;
			more2write_1= 1;
		}
		return;
	}
	if (result == -1 && error == EINTR)
	{
		/* Never mind. */
		return;
	}
	if (result == 0)
	{
		msg("connection closed.");
		done(0);
	}
	fprintf(stderr, "completed_rd_rem: %d, %d\n", result, error);
	abort();
}

static void
completed_wr_rem(result, error)
	int result;
	int error;
{
	inprogress_wr_rem= 0;

	if (result > 0)
	{
		if (extra_wr_rem != NULL)
		{
			assert (result <= extra_wr_rem_size);
			extra_wr_rem_size -= result;
			extra_wr_rem_offset += result;
			if (extra_wr_rem_size == 0)
			{
				free(extra_wr_rem);
				extra_wr_rem= NULL;
				if (wr_rem_size == 0)
				{
					more2write_rem= 0;
					more2read_0= 1;
				}
			}
			return;
		}

		assert (result <= wr_rem_size);
		wr_rem_size -= result;
		wr_rem_offset += result;
		if (wr_rem_size == 0)
		{
			more2write_rem= 0;
			more2read_0= 1;
		}
		return;
	}
	fprintf(stderr, "completed_wr_rem: %d, %d\n", result, error);
	abort();
}

static void
do_urg(urg_byte)
	int urg_byte;
{
#if DEBUG
	fprintf(stderr, "rlogin: warning got urg_byte 0x%x\r\n", urg_byte);
#endif
	if (urg_byte & TIOCPKT_WINDOW)
	{
		if (dosigwinch == 0)
		{
			sendwindow();
			signal(SIGWINCH, sigwinch);
		}
		dosigwinch= 1;
	}
}

static void
echo(c)
	int c;
{
	u_char c1;
	char *new_buf;

	new_buf= realloc(extra_1_new, extra_1_new_size+6);
	if (new_buf == NULL)
		return;
	extra_1_new= new_buf;
	new_buf= extra_1_new+extra_1_new_size;

	c1= escapechar;
	if (c1 < ' ')
	{
		*new_buf++= '^';
		*new_buf++= c1 + '@';
	}
	else if (c1 == 0x7f)
	{
		*new_buf++= '^';
		*new_buf++= '?';
	}
	else
		*new_buf++= c1;

	if (c < ' ')
	{
		*new_buf++= '^';
		*new_buf++= c + '@';
	}
	else if (c == 0x7f)
	{
		*new_buf++= '^';
		*new_buf++= '?';
	}
	else
		*new_buf++= c;

	*new_buf++= '\r';
	*new_buf++= '\n';
	extra_1_new_size= new_buf-extra_1_new;
	more2write_1= 1;
}

static void
finish()
{
	done(0);
}

static char cmdbuf[256];

static void
subshell()
{
	/* Start a subshell. Based on the first character of the command,
	 * the tcp connection will be present at fd 3 ('+'), or at
	 * fd 0 and fd 1 ('=')
	 */
	int r, pid, stat, len;
	char *shell, *cmd;

	/* cancel the reads and writes that are in progress. */
	if (inprogress_0)
	{
		r= fcancel(0, ASIO_READ);
		if (r != 0) abort();
	}
	if (inprogress_1)
	{
		r= fcancel(1, ASIO_WRITE);
		if (r != 0) abort();
	}
	if (inprogress_rd_rem)
	{
		r= fcancel(rem, ASIO_READ);
		if (r != 0) abort();
	}
	if (inprogress_wr_rem)
	{
		r= fcancel(rem, ASIO_WRITE);
		if (r != 0) abort();
	}

	mode(0);

	pid= fork();
	if (pid == -1) abort();
	if (pid != 0)
	{
		r= waitpid(pid, &stat, 0);
		if (r != pid) abort();

#if DEBUG
		fprintf(stderr, "stat: 0x%x\n", stat);
#endif
		mode(1);
		return;
	}

	(void)signal(SIGINT, SIG_DFL);

	shell= getenv("SHELL");
	if (shell == NULL)
		shell= "/bin/sh";
	printf("~!\ncommand [%s]: ", shell);
	cmd= fgets(cmdbuf, sizeof(cmdbuf), stdin);
	if (cmd == NULL)
		exit(0);
#if DEBUG
	printf("got command '%s'\n", cmd);
#endif

	/* Strip the trailing newline */
	len= strlen(cmd);
	if (len > 0 && cmd[len-1] == '\n')
		cmd[len-1]= '\0';
	else
		printf("\n");

	/* Skip leading white space */
	while (*cmd != '\0' && isspace(*cmd))
		cmd++;

	if (*cmd == '+')
	{
		if (rem != 3)
		{
			dup2(rem, 3);
			close(rem);
		}
		cmd++;
	}
	else if (*cmd == '=')
	{
		dup2(rem, 0);
		dup2(rem, 1);
		close(rem);
		cmd++;
	}
	else
		close(rem);
	if (*cmd == '\0')
	{
		r= execl(shell, shell, NULL);
	}
	else
	{
		r= execl("/bin/sh", "sh", "-c", cmd, NULL);
	}
	printf("exec failed: %d, %d\n", r, errno);
	exit(0);
}
#endif /* __minix_vmd */