Annotation of libaitio/src/pty.c, revision 1.8

1.2       misho       1: /*************************************************************************
                      2: * (C) 2011 AITNET ltd - Sofia/Bulgaria - <misho@aitbg.com>
                      3: *  by Michael Pounov <misho@openbsd-bg.org>
                      4: *
                      5: * $Author: misho $
1.8     ! misho       6: * $Id: pty.c,v 1.7.8.1 2016/08/10 15:18:23 misho Exp $
1.2       misho       7: *
                      8: **************************************************************************
                      9: The ELWIX and AITNET software is distributed under the following
                     10: terms:
                     11: 
                     12: All of the documentation and software included in the ELWIX and AITNET
                     13: Releases is copyrighted by ELWIX - Sofia/Bulgaria <info@elwix.org>
                     14: 
1.8     ! misho      15: Copyright 2004 - 2016
1.2       misho      16:        by Michael Pounov <misho@elwix.org>.  All rights reserved.
                     17: 
                     18: Redistribution and use in source and binary forms, with or without
                     19: modification, are permitted provided that the following conditions
                     20: are met:
                     21: 1. Redistributions of source code must retain the above copyright
                     22:    notice, this list of conditions and the following disclaimer.
                     23: 2. Redistributions in binary form must reproduce the above copyright
                     24:    notice, this list of conditions and the following disclaimer in the
                     25:    documentation and/or other materials provided with the distribution.
                     26: 3. All advertising materials mentioning features or use of this software
                     27:    must display the following acknowledgement:
                     28: This product includes software developed by Michael Pounov <misho@elwix.org>
                     29: ELWIX - Embedded LightWeight unIX and its contributors.
                     30: 4. Neither the name of AITNET nor the names of its contributors
                     31:    may be used to endorse or promote products derived from this software
                     32:    without specific prior written permission.
                     33: 
                     34: THIS SOFTWARE IS PROVIDED BY AITNET AND CONTRIBUTORS ``AS IS'' AND
                     35: ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
                     36: IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     37: ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
                     38: FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     39: DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
                     40: OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                     41: HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
                     42: LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
                     43: OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
                     44: SUCH DAMAGE.
                     45: */
                     46: #include "global.h"
                     47: 
                     48: 
                     49: /*
1.4       misho      50:  * ioAllocPTY() - Allocate new PTY and TTY
1.3       misho      51:  *
1.2       misho      52:  * @ptyfd = master fd, pty
                     53:  * @ttyfd = slave fd, tty
                     54:  * @name = tty device name if not null
                     55:  * @namesiz = name length, must be above 63 bytes.
                     56:  * @term = termios for terminal
                     57:  * @winz = winsize for terminal
                     58:  * return: -1 error or 0 ok
                     59:  */
1.5       misho      60: int
1.2       misho      61: ioAllocPTY(int *ptyfd, int *ttyfd, char * __restrict name, int namesiz, 
                     62:                struct termios * __restrict term, struct winsize * __restrict winz)
                     63: {
                     64:        assert(ptyfd && ttyfd);
                     65:        if (!ptyfd || !ttyfd || (name && namesiz < 64)) {
1.4       misho      66:                io_SetErr(EINVAL, "Invalid arguments");
1.2       misho      67:                return -1;
                     68:        }
                     69: 
                     70:        memset(name, 0, namesiz);
                     71:        if (openpty(ptyfd, ttyfd, name, term, winz) == -1) {
                     72:                LOGERR;
                     73:                return -1;
                     74:        }
                     75: 
                     76:        return 0;
                     77: }
                     78: 
                     79: /*
1.4       misho      80:  * ioFreePTY() - Release PTY and TTY device
1.3       misho      81:  *
1.2       misho      82:  * @ptyfd = master fd, pty (==-1 skip closing pty)
                     83:  * @ttyname = tty filename
                     84:  * return: none
                     85:  */
1.5       misho      86: void
1.2       misho      87: ioFreePTY(int ptyfd, const char *ttyname)
                     88: {
                     89:        assert(ttyname);
                     90:        if (!ttyname)
                     91:                return;
                     92: 
                     93:        if (ptyfd != -1)
                     94:                close(ptyfd);
1.6       misho      95:        if (*ttyname) {
1.2       misho      96:                chown(ttyname, (uid_t) 0, (gid_t) 0);
                     97:                chmod(ttyname, (mode_t) 0666);
                     98:        }
                     99: }
                    100: 
                    101: /*
1.4       misho     102:  * ioChgWinPTY() - Change window size of PTY
1.3       misho     103:  *
1.2       misho     104:  * @ptyfd = master fd, pty
                    105:  * @row = row
                    106:  * @col = col
                    107:  * @xpxl = x pixels
                    108:  * @ypxl = y pixels
                    109:  * return: -1 error or 0 ok
                    110:  */
1.5       misho     111: int
1.2       misho     112: ioChgWinPTY(int ptyfd, u_short row, u_short col, u_short xpxl, u_short ypxl)
                    113: {
                    114:        struct winsize w;
                    115: 
                    116:        w.ws_row = row;
                    117:        w.ws_col = col;
                    118:        w.ws_xpixel = xpxl;
                    119:        w.ws_ypixel = ypxl;
                    120: 
                    121:        if (ioctl(ptyfd, TIOCSWINSZ, &w) == -1) {
                    122:                LOGERR;
                    123:                return -1;
                    124:        }
                    125: 
                    126:        return 0;
                    127: }
                    128: 
                    129: /*
1.4       misho     130:  * ioSetOwnerTTY() - Set owner to TTY
1.3       misho     131:  *
1.2       misho     132:  * @ttyname = tty filename
                    133:  * @UID = uid
                    134:  * @GID = gid
                    135:  * return: -1 error or 0 ok
                    136:  */
                    137: int
                    138: ioSetOwnerTTY(const char *ttyname, uid_t UID, gid_t GID)
                    139: {
                    140:        struct group *grp;
                    141:        gid_t gid;
                    142:        mode_t mode;
                    143:        struct stat st;
                    144: 
                    145:        assert(ttyname);
                    146:        if (!ttyname) {
1.4       misho     147:                io_SetErr(EINVAL, "Invalid arguments");
1.2       misho     148:                return -1;
                    149:        }
                    150: 
                    151:        grp = getgrnam("tty");
                    152:        if (!grp) {
                    153:                gid = GID;
                    154:                mode = S_IRUSR | S_IWUSR | S_IWGRP | S_IWOTH;
                    155:        } else {
                    156:                gid = grp->gr_gid;
                    157:                mode = S_IRUSR | S_IWUSR | S_IWGRP;
                    158:        }
                    159: 
                    160:        if (stat(ttyname, &st) == -1) {
                    161:                LOGERR;
                    162:                return -1;
                    163:        }
                    164: 
                    165:        if (st.st_uid != UID || st.st_gid != gid)
                    166:                if (chown(ttyname, UID, gid) == -1) {
                    167:                        LOGERR;
                    168:                        return -1;
                    169:                }
                    170:        if ((st.st_mode & (S_IRWXU|S_IRWXG|S_IRWXO)) != mode)
                    171:                if (chmod(ttyname, mode) == -1) {
                    172:                        LOGERR;
                    173:                        return -1;
                    174:                }
                    175: 
                    176:        return 0;
                    177: }
                    178: 
                    179: /*
1.4       misho     180:  * ioSetSidTTY() - Makes the process's controlling TTY and sets it to sane modes.
1.3       misho     181:  *
1.2       misho     182:  * @ttyfd = slave fd, tty
                    183:  * @ttyname = tty filename
                    184:  * return: -1 error or 0 ok
                    185:  */
                    186: int
                    187: ioSetSidTTY(int *ttyfd, const char *ttyname)
                    188: {
                    189:        int fd;
                    190: 
                    191:        /* First disconnect from the old controlling tty. */
                    192: #ifdef TIOCNOTTY
                    193:        fd = open(_PATH_TTY, O_RDWR | O_NOCTTY);
                    194:        if (fd >= 0) {
                    195:                ioctl(fd, TIOCNOTTY, NULL);
                    196:                close(fd);
                    197:        }
                    198: #endif
                    199:        setsid();
                    200: 
                    201:        /* Verify that we are successfully disconnected from the controlling tty. */
                    202:        fd = open(_PATH_TTY, O_RDWR | O_NOCTTY);
                    203:        if (fd >= 0) {
1.4       misho     204:                io_SetErr(ENXIO, "Failed to disconnect from controlling tty");
1.2       misho     205:                close(fd);
                    206:                return -1;
                    207:        }
                    208:        /* Make it our controlling tty. */
                    209: #ifdef TIOCSCTTY
                    210:        if (ioctl(*ttyfd, TIOCSCTTY, NULL) == -1) {
                    211:                LOGERR;
                    212:                return -1;
                    213:        }
                    214: #endif
                    215:        fd = open(ttyname, O_RDWR);
                    216:        if (fd == -1) {
                    217:                LOGERR;
                    218:                return -1;
                    219:        } else
                    220:                close(fd);
                    221: 
                    222:        /* Verify that we now have a controlling tty. */
                    223:        fd = open(_PATH_TTY, O_WRONLY);
                    224:        if (fd == -1) {
                    225:                LOGERR;
                    226:                return -1;
                    227:        } else
                    228:                close(fd);
                    229: 
                    230:        /* redirect standart handles to tty */
                    231:        dup2(*ttyfd, STDIN_FILENO);
                    232:        dup2(*ttyfd, STDOUT_FILENO);
                    233:        dup2(*ttyfd, STDERR_FILENO);
                    234:        if (*ttyfd > 2)
                    235:                close(*ttyfd);
                    236: 
                    237:        /* NOW TTY IS READY! */
                    238:        return 0;
                    239: }
                    240: 
                    241: /*
1.4       misho     242:  * ioSetRAWMode() - Enter into RAW mode
1.3       misho     243:  *
1.2       misho     244:  * @fd = tty fd
                    245:  * @otio = saved old termios for later restore if !=NULL
                    246:  * return: -1 error or 0 ok
                    247:  */
1.5       misho     248: int
1.2       misho     249: ioSetRAWMode(int fd, struct termios *otio)
                    250: {
                    251:        struct termios tio;
                    252: 
                    253:        if (tcgetattr(fd, &tio) == -1) {
                    254:                LOGERR;
                    255:                return -1;
                    256:        }
                    257:        if (otio)
                    258:                *otio = tio;
                    259: 
                    260:        tio.c_iflag |= IGNPAR;
                    261:        tio.c_iflag &= ~(ISTRIP | INLCR | IGNCR | ICRNL | IXON | IXANY | IXOFF);
                    262: #ifdef IUCLC
                    263:        tio.c_iflag &= ~IUCLC;
                    264: #endif
                    265:        tio.c_lflag &= ~(ISIG | ICANON | ECHO | ECHOE | ECHOK | ECHONL);
                    266: #ifdef IEXTEN
                    267:        tio.c_lflag &= ~IEXTEN;
                    268: #endif
                    269:        tio.c_oflag &= ~OPOST;
                    270:        tio.c_cc[VMIN] = 1;
                    271:        tio.c_cc[VTIME] = 0;
                    272: 
                    273:        if (tcsetattr(fd, TCSADRAIN, &tio) == -1) {
                    274:                LOGERR;
                    275:                return -1;
                    276:        }
                    277: 
                    278:        return 0;
                    279: }
                    280: 
                    281: /*
1.4       misho     282:  * ioRestoreMode() - Restore termios to tty fd
1.3       misho     283:  *
1.2       misho     284:  * @fd = tty fd
                    285:  * @tio = termios structure for restore
                    286:  * return: -1 error or 0 ok
                    287:  */
1.5       misho     288: int
1.2       misho     289: ioRestoreMode(int fd, struct termios tio)
                    290: {
                    291:        if (tcsetattr(fd, TCSADRAIN, &tio) == -1) {
                    292:                LOGERR;
                    293:                return -1;
                    294:        }
                    295: 
                    296:        return 0;
                    297: }
                    298: 
                    299: /*
1.4       misho     300:  * ioForkPTY() - Fork new process with session leader and new TTY
1.3       misho     301:  *
1.2       misho     302:  * @ptyfd = master fd, pty
                    303:  * @name = tty device name if not null
                    304:  * @namesiz = name length, must be above 63 bytes.
                    305:  * @term = termios for terminal
                    306:  * @winz = winsize for terminal
                    307:  * @otio = old termios structure for restore
                    308:  * return: -1 error, 0 child process or >0 parent: pid of child
                    309:  */
                    310: pid_t
                    311: ioForkPTY(int *ptyfd, char * __restrict name, int namesiz, struct termios * __restrict term, 
                    312:                struct winsize * __restrict winz, struct termios * __restrict otio)
                    313: {
                    314:        int ttyfd;
                    315:        pid_t pid;
                    316: 
                    317:        if (ioAllocPTY(ptyfd, &ttyfd, name, namesiz, term, winz))
                    318:                return -1;
                    319: 
                    320:        switch ((pid = fork())) {
                    321:                case -1:
                    322:                        LOGERR;
                    323:                        return -1;
                    324:                case 0:
                    325:                        if (ioSetOwnerTTY(name, getuid(), getgid()) == -1) {
                    326:                                ioFreePTY(*ptyfd, name);
                    327:                                return -1;
                    328:                        }
                    329:                        if (ioSetSidTTY(&ttyfd, name) == -1) {
                    330:                                ioFreePTY(*ptyfd, name);
                    331:                                return -1;
                    332:                        }
                    333:                        close(*ptyfd);
                    334: 
                    335:                        /* CHILD */
                    336:                        break;
                    337:                default:
                    338:                        close(ttyfd);
                    339: 
                    340:                        /* PARENT */
                    341:                        break;
                    342:        }
                    343: 
                    344:        return pid;
                    345: }

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