diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/speed.c')
| -rw-r--r-- | sysdeps/unix/sysv/linux/speed.c | 363 |
1 files changed, 316 insertions, 47 deletions
diff --git a/sysdeps/unix/sysv/linux/speed.c b/sysdeps/unix/sysv/linux/speed.c index 017f741..4efb0de 100644 --- a/sysdeps/unix/sysv/linux/speed.c +++ b/sysdeps/unix/sysv/linux/speed.c @@ -16,82 +16,351 @@ License along with the GNU C Library; if not, see <https://www.gnu.org/licenses/>. */ -#include <stddef.h> -#include <errno.h> -#include <termios.h> -#include <sysdep.h> +#include <termios_internals.h> -/* This is a gross hack around a kernel bug. If the cfsetispeed functions - is called with the SPEED argument set to zero this means use the same - speed as for output. But we don't have independent input and output - speeds and therefore cannot record this. +/* Conversions between legacy c_cflag fields and actual baud rates */ - We use an unused bit in the `c_iflag' field to keep track of this - use of `cfsetispeed'. The value here must correspond to the one used - in `tcsetattr.c'. */ -#define IBAUD0 020000000000 +/* These expressions may seem complicated; the _cbix() macro + compresses the CBAUD field into an index in the range 0-31. On most + Linux platforms, the CBAUD field is 5 bits, but the topmost bit + indicated by CBAUDEX, is discontinous with the rest. + + The resulting masks look like: + + Alpha PowerPC others + + CBAUD 0x001f 0x00ff 0x100f + CBAUDEX 0x0000 0x0010 0x1000 + + LOWCBAUD 0x001f 0x000f 0x000f + CBAUDMASK 0x001f 0x001f 0x100f + + CBAUDMASK is used to test for invalid values passed to the + compatibility functions or in termios::c_cflag on PowerPC. + + The divide-multiply sequence in the _cbix() macro gets converted + to shift and masks as necessary by the compiler. */ + +#define LOWCBAUD (CBAUD & (CBAUDEX-1)) +#define _cbix(x) (((x) & LOWCBAUD) | \ + (CBAUDEX ? ((x) & CBAUDEX)/CBAUDEX * (LOWCBAUD+1) : 0)) +#define CBAUDMASK (LOWCBAUD | CBAUDEX) + +/* Compile time sanity checks for broken CBAUD or CIBAUD definitions */ +#if CIBAUD != (CBAUD << IBSHIFT) +# error "CIBAUD should == CBAUD << IBSHIFT" +#elif CBAUDEX & (CBAUDEX-1) +# error "CBAUDEX should either be 0 or a single bit" +#elif !(CBAUD & 1) +# error "The CBAUD field should start at bit 0" +#elif CBAUDEX & ~CBAUD +# error "CBAUD should include the CBAUDEX bit" +#endif + +speed_t +___cbaud_to_speed (tcflag_t c_cflag, speed_t other) +{ + static const speed_t cbaudix_to_speed [] = + { + [0 ... _cbix(CBAUDMASK)] = -1, + [_cbix(__B0)] = 0, + [_cbix(__B50)] = 50, + [_cbix(__B75)] = 75, + [_cbix(__B110)] = 110, + [_cbix(__B134)] = 134, + [_cbix(__B150)] = 150, + [_cbix(__B200)] = 200, + [_cbix(__B300)] = 300, + [_cbix(__B600)] = 600, + [_cbix(__B1200)] = 1200, + [_cbix(__B1800)] = 1800, + [_cbix(__B2400)] = 2400, + [_cbix(__B4800)] = 4800, + [_cbix(__B9600)] = 9600, + [_cbix(__B19200)] = 19200, + [_cbix(__B38400)] = 38400, + [_cbix(__B57600)] = 57600, + [_cbix(__B115200)] = 115200, + [_cbix(__B230400)] = 230400, + [_cbix(__B460800)] = 460800, + [_cbix(__B500000)] = 500000, + [_cbix(__B576000)] = 576000, + [_cbix(__B921600)] = 921600, + [_cbix(__B1000000)] = 1000000, + [_cbix(__B1152000)] = 1152000, + [_cbix(__B1500000)] = 1500000, + [_cbix(__B2000000)] = 2000000, +#ifdef __B7200 + [_cbix(__B7200)] = 7200, +#endif +#ifdef __B14400 + [_cbix(__B14400)] = 14400, +#endif +#ifdef __B28800 + [_cbix(__B28800)] = 28800, +#endif +#ifdef __B76800 + [_cbix(__B76800)] = 76800, +#endif +#ifdef __B153600 + [_cbix(__B153600)] = 153600, +#endif +#ifdef __B307200 + [_cbix(__B307200)] = 307200, +#endif +#ifdef __B614400 + [_cbix(__B614400)] = 614400, +#endif +#ifdef __B2500000 + [_cbix(__B2500000)] = 2500000, +#endif +#ifdef __B3000000 + [_cbix(__B3000000)] = 3000000, +#endif +#ifdef __B3500000 + [_cbix(__B3500000)] = 3500000, +#endif +#ifdef __B4000000 + [_cbix(__B4000000)] = 4000000, +#endif + }; + speed_t speed; + + if (c_cflag & (tcflag_t)(~CBAUDMASK)) + return other; + + speed = cbaudix_to_speed[_cbix(c_cflag)]; + return speed == (speed_t)-1 ? other : speed; +} + +tcflag_t +___speed_to_cbaud (speed_t speed) +{ + switch (speed) { + case 0: + return __B0; + case 50: + return __B50; + case 75: + return __B75; + case 110: + return __B110; + case 134: + return __B134; + case 150: + return __B150; + case 200: + return __B200; + case 300: + return __B300; + case 600: + return __B600; + case 1200: + return __B1200; + case 1800: + return __B1800; + case 2400: + return __B2400; + case 4800: + return __B4800; + case 9600: + return __B9600; + case 19200: + return __B19200; + case 38400: + return __B38400; + case 57600: + return __B57600; + case 115200: + return __B115200; + case 230400: + return __B230400; + case 460800: + return __B460800; + case 500000: + return __B500000; + case 576000: + return __B576000; + case 921600: + return __B921600; + case 1000000: + return __B1000000; + case 1152000: + return __B1152000; + case 1500000: + return __B1500000; + case 2000000: + return __B2000000; +#ifdef __B76800 + case 76800: + return __B76800; +#endif +#ifdef __B153600 + case 153600: + return __B153600; +#endif +#ifdef __B307200 + case 307200: + return __B307200; +#endif +#ifdef __B614400 + case 614400: + return __B614400; +#endif +#ifdef __B2500000 + case 2500000: + return __B2500000; +#endif +#ifdef __B3000000 + case 3000000: + return __B3000000; +#endif +#ifdef __B3500000 + case 3500000: + return __B3500000; +#endif +#ifdef __B4000000 + case 4000000: + return __B4000000; +#endif + default: + return __BOTHER; + } +} + + +/* Canonicalize the representation of speed fields in a kernel + termios2 structure. Specifically, if there is a valid legacy cbaud + representation (not __BOTHER), use it and propagate the + corresponding speed value to ispeed/ospeed, otherwise the other way + around if possible. Finally, if the input speed is zero, copy the + output speed to the input speed. + + The kernel doesn't do this canonicalization, which can affect + legacy utilities, so do it here. + + This is used by tcgetattr() and tcsetattr(). */ +void +___termios2_canonicalize_speeds (struct termios2 *k_termios_p) +{ + k_termios_p->c_ospeed = + ___cbaud_to_speed (cbaud (k_termios_p->c_cflag), k_termios_p->c_ospeed); + k_termios_p->c_ispeed = + ___cbaud_to_speed (cibaud (k_termios_p->c_cflag), k_termios_p->c_ispeed); + + if (!k_termios_p->c_ispeed) + k_termios_p->c_ispeed = k_termios_p->c_ospeed; + + k_termios_p->c_cflag &= ~(CBAUD | CIBAUD); + k_termios_p->c_cflag |= ___speed_to_cbaud (k_termios_p->c_ospeed); + k_termios_p->c_cflag |= ___speed_to_cbaud (k_termios_p->c_ispeed) << IBSHIFT; +} /* Return the output baud rate stored in *TERMIOS_P. */ speed_t -cfgetospeed (const struct termios *termios_p) +__cfgetospeed (const struct termios *termios_p) { - return termios_p->c_cflag & (CBAUD | CBAUDEX); + return termios_p->c_ospeed; } +libc_hidden_def (__cfgetospeed) +versioned_symbol (libc, __cfgetospeed, cfgetospeed, GLIBC_2_42); -/* Return the input baud rate stored in *TERMIOS_P. - Although for Linux there is no difference between input and output - speed, the numerical 0 is a special case for the input baud rate. It - should set the input baud rate to the output baud rate. */ +/* Return the input baud rate stored in *TERMIOS_P. */ speed_t -cfgetispeed (const struct termios *termios_p) +__cfgetispeed (const struct termios *termios_p) { - return ((termios_p->c_iflag & IBAUD0) - ? 0 : termios_p->c_cflag & (CBAUD | CBAUDEX)); + return termios_p->c_ispeed; } +libc_hidden_def (__cfgetispeed) +versioned_symbol (libc, __cfgetispeed, cfgetispeed, GLIBC_2_42); /* Set the output baud rate stored in *TERMIOS_P to SPEED. */ int -cfsetospeed (struct termios *termios_p, speed_t speed) +__cfsetospeed (struct termios *termios_p, speed_t speed) { - if ((speed & ~CBAUD) != 0 - && (speed < B57600 || speed > __MAX_BAUD)) - return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL); + tcflag_t cbaud = ___speed_to_cbaud (speed); -#if _HAVE_STRUCT_TERMIOS_C_OSPEED termios_p->c_ospeed = speed; + termios_p->c_cflag &= ~CBAUD; + termios_p->c_cflag |= cbaud; + + return 0; +} +libc_hidden_def (__cfsetospeed) +versioned_symbol (libc, __cfsetospeed, cfsetospeed, GLIBC_2_42); + +/* Set the input baud rate stored in *TERMIOS_P to SPEED. */ +int +__cfsetispeed (struct termios *termios_p, speed_t speed) +{ + tcflag_t cbaud = ___speed_to_cbaud (speed); + + termios_p->c_ispeed = speed; + termios_p->c_cflag &= ~CIBAUD; + termios_p->c_cflag |= cbaud << IBSHIFT; + + return 0; +} +libc_hidden_def (__cfsetispeed) +versioned_symbol (libc, __cfsetispeed, cfsetispeed, GLIBC_2_42); + +#if _TERMIOS_OLD_COMPAT + +/* Legacy versions which returns cbaud-encoded speed_t values */ + +speed_t +attribute_compat_text_section +__old_cfgetospeed (const old_termios_t *termios_p) +{ + return cbaud (termios_p->c_cflag); +} +compat_symbol (libc, __old_cfgetospeed, cfgetospeed, GLIBC_2_0); + +speed_t +attribute_compat_text_section +__old_cfgetispeed (const old_termios_t *termios_p) +{ + return cibaud (termios_p->c_cflag); +} +compat_symbol (libc, __old_cfgetispeed, cfgetispeed, GLIBC_2_0); + +int +attribute_compat_text_section +__old_cfsetospeed (old_termios_t *termios_p, speed_t speed) +{ + speed_t real_speed = ___cbaud_to_speed (speed, -1); + if (real_speed == (speed_t)-1) + return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL); + +#if !_HAVE_STRUCT_OLD_TERMIOS + /* Otherwise this field doesn't exist in old_termios_t */ + termios_p->c_ospeed = real_speed; #endif - termios_p->c_cflag &= ~(CBAUD | CBAUDEX); + termios_p->c_cflag &= ~CBAUD; termios_p->c_cflag |= speed; return 0; } -libc_hidden_def (cfsetospeed) +compat_symbol (libc, __old_cfsetospeed, cfsetospeed, GLIBC_2_0); - -/* Set the input baud rate stored in *TERMIOS_P to SPEED. - Although for Linux there is no difference between input and output - speed, the numerical 0 is a special case for the input baud rate. It - should set the input baud rate to the output baud rate. */ int -cfsetispeed (struct termios *termios_p, speed_t speed) +attribute_compat_text_section +__old_cfsetispeed (old_termios_t *termios_p, speed_t speed) { - if ((speed & ~CBAUD) != 0 - && (speed < B57600 || speed > __MAX_BAUD)) + speed_t real_speed = ___cbaud_to_speed (speed, -1); + if (real_speed == (speed_t)-1) return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL); -#if _HAVE_STRUCT_TERMIOS_C_ISPEED - termios_p->c_ispeed = speed; +#if !_HAVE_STRUCT_OLD_TERMIOS + /* Otherwise this field doesn't exist in old_termios_t */ + termios_p->c_ispeed = real_speed; #endif - if (speed == 0) - termios_p->c_iflag |= IBAUD0; - else - { - termios_p->c_iflag &= ~IBAUD0; - termios_p->c_cflag &= ~(CBAUD | CBAUDEX); - termios_p->c_cflag |= speed; - } + termios_p->c_cflag &= ~CIBAUD; + termios_p->c_cflag |= speed << IBSHIFT; return 0; } -libc_hidden_def (cfsetispeed) +compat_symbol (libc, __old_cfsetispeed, cfsetispeed, GLIBC_2_0); + +#endif /* _TERMIOS_OLD_COMPAT */ |