1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 4 */ 5 6 #include <stdio.h> 7 #include <stdlib.h> 8 #include <unistd.h> 9 #include <errno.h> 10 #include <fcntl.h> 11 #include <string.h> 12 #include <termios.h> 13 #include <sys/stat.h> 14 #include "chan_user.h" 15 #include <os.h> 16 #include <um_malloc.h> 17 18 struct pty_chan { 19 void (*announce)(char *dev_name, int dev); 20 int dev; 21 int raw; 22 struct termios tt; 23 char dev_name[sizeof("/dev/pts/0123456\0")]; 24 }; 25 26 static void *pty_chan_init(char *str, int device, const struct chan_opts *opts) 27 { 28 struct pty_chan *data; 29 30 data = uml_kmalloc(sizeof(*data), UM_GFP_KERNEL); 31 if (data == NULL) 32 return NULL; 33 34 *data = ((struct pty_chan) { .announce = opts->announce, 35 .dev = device, 36 .raw = opts->raw }); 37 return data; 38 } 39 40 static int pts_open(int input, int output, int primary, void *d, 41 char **dev_out) 42 { 43 struct pty_chan *data = d; 44 char *dev; 45 int fd, err; 46 47 fd = get_pty(); 48 if (fd < 0) { 49 err = -errno; 50 printk(UM_KERN_ERR "open_pts : Failed to open pts\n"); 51 return err; 52 } 53 54 if (data->raw) { 55 CATCH_EINTR(err = tcgetattr(fd, &data->tt)); 56 if (err) 57 goto out_close; 58 59 err = raw(fd); 60 if (err) 61 goto out_close; 62 } 63 64 dev = ptsname(fd); 65 sprintf(data->dev_name, "%s", dev); 66 *dev_out = data->dev_name; 67 68 if (data->announce) 69 (*data->announce)(dev, data->dev); 70 71 return fd; 72 73 out_close: 74 close(fd); 75 return err; 76 } 77 78 static int getmaster(char *line) 79 { 80 struct stat buf; 81 char *pty, *bank, *cp; 82 int master, err; 83 84 pty = &line[strlen("/dev/ptyp")]; 85 for (bank = "pqrs"; *bank; bank++) { 86 line[strlen("/dev/pty")] = *bank; 87 *pty = '0'; 88 /* Did we hit the end ? */ 89 if ((stat(line, &buf) < 0) && (errno == ENOENT)) 90 break; 91 92 for (cp = "0123456789abcdef"; *cp; cp++) { 93 *pty = *cp; 94 master = open(line, O_RDWR); 95 if (master >= 0) { 96 char *tp = &line[strlen("/dev/")]; 97 98 /* verify slave side is usable */ 99 *tp = 't'; 100 err = access(line, R_OK | W_OK); 101 *tp = 'p'; 102 if (!err) 103 return master; 104 close(master); 105 } 106 } 107 } 108 109 printk(UM_KERN_ERR "getmaster - no usable host pty devices\n"); 110 return -ENOENT; 111 } 112 113 static int pty_open(int input, int output, int primary, void *d, 114 char **dev_out) 115 { 116 struct pty_chan *data = d; 117 int fd, err; 118 char dev[sizeof("/dev/ptyxx\0")] = "/dev/ptyxx"; 119 120 fd = getmaster(dev); 121 if (fd < 0) 122 return fd; 123 124 if (data->raw) { 125 err = raw(fd); 126 if (err) { 127 close(fd); 128 return err; 129 } 130 } 131 132 if (data->announce) 133 (*data->announce)(dev, data->dev); 134 135 sprintf(data->dev_name, "%s", dev); 136 *dev_out = data->dev_name; 137 138 return fd; 139 } 140 141 const struct chan_ops pty_ops = { 142 .type = "pty", 143 .init = pty_chan_init, 144 .open = pty_open, 145 .close = generic_close, 146 .read = generic_read, 147 .write = generic_write, 148 .console_write = generic_console_write, 149 .window_size = generic_window_size, 150 .free = generic_free, 151 .winch = 0, 152 }; 153 154 const struct chan_ops pts_ops = { 155 .type = "pts", 156 .init = pty_chan_init, 157 .open = pts_open, 158 .close = generic_close, 159 .read = generic_read, 160 .write = generic_write, 161 .console_write = generic_console_write, 162 .window_size = generic_window_size, 163 .free = generic_free, 164 .winch = 0, 165 }; 166