[git commit master 1/1] getty: comment out parity detection code; improve usage text
Denys Vlasenko
vda.linux at googlemail.com
Sat Jan 22 02:06:40 UTC 2011
commit: http://git.busybox.net/busybox/commit/?id=2b57b6cd43211e2430c78caa0895f41376f29dc1
branch: http://git.busybox.net/busybox/commit/?id=refs/heads/master
function old new delta
packed_usage 28155 28191 +36
static.erase 12 - -12
getty_main 1847 1621 -226
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 1/1 up/down: 36/-238) Total: -202 bytes
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
loginutils/getty.c | 112 +++++++++++++++++++++++++++++++++------------------
1 files changed, 72 insertions(+), 40 deletions(-)
diff --git a/loginutils/getty.c b/loginutils/getty.c
index 0f5e333..94c9147 100644
--- a/loginutils/getty.c
+++ b/loginutils/getty.c
@@ -58,9 +58,16 @@ static FILE *dbf;
* and for line editing at the same time.
*/
-/* I doubt there are systems which still need this */
+/* I doubt there are systems which still... */
+/* ...have only uppercase: */
#undef HANDLE_ALLCAPS
+/* ...use # and @ for backspace and line erase: */
#undef ANCIENT_BS_KILL_CHARS
+/* It actually makes sense (tries to guess parity by looking at 7th bit)
+ * but it's broken, and interferes with non-ASCII login names
+ * (yes, I did receive complains from real users):
+ */
+#undef BROKEN_PARITY_DETECTION_CODE
#undef _PATH_LOGIN
#define _PATH_LOGIN "/bin/login"
@@ -108,8 +115,11 @@ struct options {
/* Storage for things detected while the login name was read. */
struct chardata {
unsigned char erase; /* erase character */
+#ifdef ANCIENT_BS_KILL_CHARS
unsigned char kill; /* kill character */
+#endif
unsigned char eol; /* end-of-line character */
+#ifdef BROKEN_PARITY_DETECTION_CODE
unsigned char parity; /* what parity did we see */
/* (parity & 1): saw odd parity char with 7th bit set */
/* (parity & 2): saw even parity char with 7th bit set */
@@ -117,7 +127,8 @@ struct chardata {
/* parity == 1: probably 7-bit, odd parity? */
/* parity == 2: probably 7-bit, even parity? */
/* parity == 3: definitely 8 bit, no parity! */
- /* Hmm... with any value of "parity" 8 bit, no parity is possible */
+ /* Hmm... with any value of parity "8 bit, no parity" is possible */
+#endif
#ifdef HANDLE_ALLCAPS
unsigned char capslock; /* upper case without lower case */
#endif
@@ -126,9 +137,13 @@ struct chardata {
/* Initial values for the above. */
static const struct chardata init_chardata = {
DEF_ERASE, /* default erase character */
+#ifdef ANCIENT_BS_KILL_CHARS
DEF_KILL, /* default kill character */
+#endif
13, /* default eol char */
+#ifdef BROKEN_PARITY_DETECTION_CODE
0, /* space parity */
+#endif
#ifdef HANDLE_ALLCAPS
0, /* no capslock */
#endif
@@ -137,21 +152,23 @@ static const struct chardata init_chardata = {
#define line_buf bb_common_bufsiz1
//usage:#define getty_trivial_usage
-//usage: "[OPTIONS] BAUD_RATE TTY [TERMTYPE]"
+//usage: "[OPTIONS] BAUD_RATE[,BAUD_RATE]... TTY [TERMTYPE]"
//usage:#define getty_full_usage "\n\n"
//usage: "Open a tty, prompt for a login name, then invoke /bin/login\n"
//usage: "\nOptions:"
//usage: "\n -h Enable hardware (RTS/CTS) flow control"
//usage: "\n -i Don't display /etc/issue"
-//usage: "\n -L Local line, don't do carrier detect"
+//usage: "\n -L Local line, set CLOCAL on it"
//usage: "\n -m Get baud rate from modem's CONNECT status message"
-//usage: "\n -w Wait for a CR or LF before sending /etc/issue"
-//usage: "\n -n Don't prompt the user for a login name"
+//usage: "\n -w Wait for CR or LF before sending /etc/issue"
+//usage: "\n -n Don't prompt for a login name"
//usage: "\n -f ISSUE_FILE Display ISSUE_FILE instead of /etc/issue"
//usage: "\n -l LOGIN Invoke LOGIN instead of /bin/login"
//usage: "\n -t SEC Terminate after SEC if no username is read"
//usage: "\n -I INITSTR Send INITSTR before anything else"
//usage: "\n -H HOST Log HOST into the utmp file as the hostname"
+//usage: "\n"
+//usage: "\nBAUD_RATE of 0 leaves it unchanged"
static const char opt_string[] ALIGN1 = "I:LH:f:hil:mt:wn";
#define F_INITSTRING (1 << 0) /* -I */
@@ -259,29 +276,27 @@ static void open_tty(const char *tty)
/* termios_init - initialize termios settings */
static void termios_init(struct termios *tp, int speed)
{
- speed_t ispeed, ospeed;
+ /* Flush input and output queues, important for modems! */
+ /* TODO: sleep(1)? Users report lost chars, and I hesitate
+ * to use tcdrain here instead of tcflush */
+ tcflush(0, TCIOFLUSH);
+
+ /* Set speed if it wasn't specified as "0" on command line. */
+ if (speed != B0) {
+ cfsetispeed(tp, speed);
+ cfsetospeed(tp, speed);
+ }
/*
* Initial termios settings: 8-bit characters, raw-mode, blocking i/o.
* Special characters are set after we have read the login name; all
* reads will be done in raw mode anyway. Errors will be dealt with
* later on.
*/
- /* flush input and output queues, important for modems! */
- tcflush(0, TCIOFLUSH);
- ispeed = ospeed = speed;
- if (speed == B0) {
- /* Speed was specified as "0" on command line.
- * Just leave it unchanged */
- ispeed = cfgetispeed(tp);
- ospeed = cfgetospeed(tp);
- }
tp->c_cflag = CS8 | HUPCL | CREAD;
if (option_mask32 & F_LOCAL)
tp->c_cflag |= CLOCAL;
- cfsetispeed(tp, ispeed);
- cfsetospeed(tp, ospeed);
-
- tp->c_iflag = tp->c_lflag = 0;
+ tp->c_iflag = 0;
+ tp->c_lflag = 0;
tp->c_oflag = OPOST | ONLCR;
tp->c_cc[VMIN] = 1;
tp->c_cc[VTIME] = 0;
@@ -388,14 +403,14 @@ static char *get_logname(char *logname, unsigned size_logname,
char *bp;
char c; /* input character, full eight bits */
char ascval; /* low 7 bits of input character */
- int bits; /* # of "1" bits per character */
- int mask; /* mask with 1 bit up */
+#ifdef BROKEN_PARITY_DETECTION_CODE
static const char erase[][3] = {/* backspace-space-backspace */
"\010\040\010", /* space parity */
"\010\040\010", /* odd parity */
"\210\240\210", /* even parity */
"\010\040\010", /* 8 bit no parity */
};
+#endif
/* NB: *cp is pre-initialized with init_chardata */
@@ -406,14 +421,13 @@ static char *get_logname(char *logname, unsigned size_logname,
/* Prompt for and read a login name. */
logname[0] = '\0';
while (!logname[0]) {
- /* Write issue file and prompt, with "parity" bit == 0. */
+ /* Write issue file and prompt. */
do_prompt(op);
/* Read name, watch for break, parity, erase, kill, end-of-line. */
bp = logname;
cp->eol = '\0';
- while (cp->eol == '\0') {
-
+ while (1) {
/* Do not report trivial EINTR/EIO errors. */
errno = EINTR; /* make read of 0 bytes be silent too */
if (read(STDIN_FILENO, &c, 1) < 1) {
@@ -427,10 +441,11 @@ static char *get_logname(char *logname, unsigned size_logname,
if (c == '\0' && op->numspeed > 1)
return NULL;
+#ifdef BROKEN_PARITY_DETECTION_CODE
/* Do parity bit handling. */
- if (!(option_mask32 & F_LOCAL) && (c & 0x80)) { /* "parity" bit on? */
- bits = 1;
- mask = 1;
+ if (!(option_mask32 & F_LOCAL) && (c & 0x80)) { /* "parity" bit on? */
+ int bits = 1;
+ int mask = 1;
while (mask & 0x7f) {
if (mask & c)
bits++; /* count "1" bits */
@@ -439,15 +454,18 @@ static char *get_logname(char *logname, unsigned size_logname,
/* ... |= 2 - even, 1 - odd */
cp->parity |= 2 - (bits & 1);
}
+ ascval = c & 0x7f;
+#else
+ ascval = c;
+#endif
/* Do erase, kill and end-of-line processing. */
- ascval = c & 0x7f;
switch (ascval) {
case CR:
case NL:
*bp = '\0'; /* terminate logname */
cp->eol = ascval; /* set end-of-line char */
- break;
+ goto got_logname;
case BS:
case DEL:
#ifdef ANCIENT_BS_KILL_CHARS
@@ -455,17 +473,25 @@ static char *get_logname(char *logname, unsigned size_logname,
#endif
cp->erase = ascval; /* set erase character */
if (bp > logname) {
+#ifdef BROKEN_PARITY_DETECTION_CODE
full_write(STDOUT_FILENO, erase[cp->parity], 3);
+#else
+ full_write(STDOUT_FILENO, "\010 \010", 3);
+#endif
bp--;
}
break;
case CTL('U'):
#ifdef ANCIENT_BS_KILL_CHARS
case '@':
-#endif
cp->kill = ascval; /* set kill character */
+#endif
while (bp > logname) {
+#ifdef BROKEN_PARITY_DETECTION_CODE
full_write(STDOUT_FILENO, erase[cp->parity], 3);
+#else
+ full_write(STDOUT_FILENO, "\010 \010", 3);
+#endif
bp--;
}
break;
@@ -474,19 +500,18 @@ static char *get_logname(char *logname, unsigned size_logname,
default:
if (ascval < ' ') {
/* ignore garbage characters */
- } else if ((int)(bp - logname) >= size_logname - 1) {
- bb_error_msg_and_die("input overrun");
- } else {
+ } else if ((int)(bp - logname) < size_logname - 1) {
full_write(STDOUT_FILENO, &c, 1); /* echo the character */
*bp++ = ascval; /* and store it */
}
break;
}
- }
- }
- /* Handle names with upper case and no lower case. */
+ } /* end of get char loop */
+ got_logname: ;
+ } /* while logname is empty */
#ifdef HANDLE_ALLCAPS
+ /* Handle names with upper case and no lower case. */
cp->capslock = all_is_upcase(logname);
if (cp->capslock) {
for (bp = logname; *bp; bp++)
@@ -520,8 +545,13 @@ static void termios_final(struct termios *tp, struct chardata *cp)
tp->c_oflag |= ONLCR; /* map NL in output to CR-NL */
}
tp->c_cc[VERASE] = cp->erase; /* set erase character */
+#ifdef ANCIENT_BS_KILL_CHARS
tp->c_cc[VKILL] = cp->kill; /* set kill character */
+#else
+ tp->c_cc[VKILL] = DEF_KILL; /* set kill character */
+#endif
+#ifdef BROKEN_PARITY_DETECTION_CODE
/* Account for the presence or absence of parity bits in input. */
switch (cp->parity) {
case 0: /* space (always 0) parity */
@@ -542,17 +572,19 @@ static void termios_final(struct termios *tp, struct chardata *cp)
// Entire parity detection madness here just begs for deletion...
break;
}
+#endif
- /* Account for upper case without lower case. */
#ifdef HANDLE_ALLCAPS
+ /* Account for upper case without lower case. */
if (cp->capslock) {
tp->c_iflag |= IUCLC;
tp->c_lflag |= XCASE;
tp->c_oflag |= OLCUC;
}
#endif
- /* Optionally enable hardware flow control */
+
#ifdef CRTSCTS
+ /* Optionally enable hardware flow control */
if (option_mask32 & F_RTSCTS)
tp->c_cflag |= CRTSCTS;
#endif
@@ -685,7 +717,7 @@ int getty_main(int argc UNUSED_PARAM, char **argv)
logname = NULL;
if (!(option_mask32 & F_NOPROMPT)) {
- /* NB:termios_init already set line speed
+ /* NB: termios_init already set line speed
* to options.speeds[0] */
int baud_index = 0;
--
1.7.3.4
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