1 | /* vi: set sw=4 ts=4: */
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2 | /* agetty.c - another getty program for Linux. By W. Z. Venema 1989
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3 | * Ported to Linux by Peter Orbaek <poe@daimi.aau.dk>
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4 | * This program is freely distributable. The entire man-page used to
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5 | * be here. Now read the real man-page agetty.8 instead.
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6 | *
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7 | * option added by Eric Rasmussen <ear@usfirst.org> - 12/28/95
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8 | *
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9 | * 1999-02-22 Arkadiusz Mickiewicz <misiek@misiek.eu.org>
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10 | * - added Native Language Support
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11 | *
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12 | * 1999-05-05 Thorsten Kranzkowski <dl8bcu@gmx.net>
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13 | * - enable hardware flow control before displaying /etc/issue
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14 | *
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15 | * Licensed under GPLv2 or later, see file LICENSE in this source tree.
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16 | */
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17 |
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18 | #include "libbb.h"
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19 | #include <syslog.h>
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20 |
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21 | #if ENABLE_FEATURE_UTMP
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22 | # include <utmp.h> /* LOGIN_PROCESS */
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23 | #endif
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24 |
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25 | #ifndef IUCLC
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26 | # define IUCLC 0
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27 | #endif
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28 |
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29 | /*
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30 | * Some heuristics to find out what environment we are in: if it is not
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31 | * System V, assume it is SunOS 4.
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32 | */
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33 | #ifdef LOGIN_PROCESS /* defined in System V utmp.h */
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34 | #include <sys/utsname.h>
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35 | #else /* if !sysV style, wtmp/utmp code is off */
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36 | #undef ENABLE_FEATURE_UTMP
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37 | #undef ENABLE_FEATURE_WTMP
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38 | #define ENABLE_FEATURE_UTMP 0
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39 | #define ENABLE_FEATURE_WTMP 0
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40 | #endif /* LOGIN_PROCESS */
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41 |
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42 | /*
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43 | * Things you may want to modify.
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44 | *
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45 | * You may disagree with the default line-editing etc. characters defined
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46 | * below. Note, however, that DEL cannot be used for interrupt generation
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47 | * and for line editing at the same time.
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48 | */
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49 |
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50 | /* I doubt there are systems which still need this */
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51 | #undef HANDLE_ALLCAPS
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52 | #undef ANCIENT_BS_KILL_CHARS
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53 |
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54 | #define _PATH_LOGIN "/bin/login"
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55 |
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56 | /* If ISSUE is not defined, getty will never display the contents of the
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57 | * /etc/issue file. You will not want to spit out large "issue" files at the
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58 | * wrong baud rate.
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59 | */
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60 | #define ISSUE "/etc/issue" /* displayed before the login prompt */
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61 |
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62 | /* Some shorthands for control characters. */
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63 | #define CTL(x) ((x) ^ 0100) /* Assumes ASCII dialect */
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64 | #define CR CTL('M') /* carriage return */
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65 | #define NL CTL('J') /* line feed */
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66 | #define BS CTL('H') /* back space */
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67 | #define DEL CTL('?') /* delete */
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68 |
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69 | /* Defaults for line-editing etc. characters; you may want to change this. */
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70 | #define DEF_ERASE DEL /* default erase character */
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71 | #define DEF_INTR CTL('C') /* default interrupt character */
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72 | #define DEF_QUIT CTL('\\') /* default quit char */
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73 | #define DEF_KILL CTL('U') /* default kill char */
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74 | #define DEF_EOF CTL('D') /* default EOF char */
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75 | #define DEF_EOL '\n'
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76 | #define DEF_SWITCH 0 /* default switch char */
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77 |
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78 | /*
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79 | * When multiple baud rates are specified on the command line, the first one
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80 | * we will try is the first one specified.
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81 | */
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82 | #define MAX_SPEED 10 /* max. nr. of baud rates */
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83 |
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84 | /* Storage for command-line options. */
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85 | struct options {
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86 | int flags; /* toggle switches, see below */
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87 | unsigned timeout; /* time-out period */
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88 | const char *login; /* login program */
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89 | const char *tty; /* name of tty */
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90 | const char *initstring; /* modem init string */
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91 | const char *issue; /* alternative issue file */
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92 | int numspeed; /* number of baud rates to try */
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93 | int speeds[MAX_SPEED]; /* baud rates to be tried */
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94 | };
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95 |
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96 | /* Storage for things detected while the login name was read. */
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97 | struct chardata {
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98 | unsigned char erase; /* erase character */
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99 | unsigned char kill; /* kill character */
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100 | unsigned char eol; /* end-of-line character */
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101 | unsigned char parity; /* what parity did we see */
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102 | /* (parity & 1): saw odd parity char with 7th bit set */
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103 | /* (parity & 2): saw even parity char with 7th bit set */
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104 | /* parity == 0: probably 7-bit, space parity? */
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105 | /* parity == 1: probably 7-bit, odd parity? */
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106 | /* parity == 2: probably 7-bit, even parity? */
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107 | /* parity == 3: definitely 8 bit, no parity! */
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108 | /* Hmm... with any value of "parity" 8 bit, no parity is possible */
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109 | #ifdef HANDLE_ALLCAPS
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110 | unsigned char capslock; /* upper case without lower case */
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111 | #endif
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112 | };
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113 |
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114 |
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115 | /* Initial values for the above. */
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116 | static const struct chardata init_chardata = {
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117 | DEF_ERASE, /* default erase character */
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118 | DEF_KILL, /* default kill character */
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119 | 13, /* default eol char */
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120 | 0, /* space parity */
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121 | #ifdef HANDLE_ALLCAPS
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122 | 0, /* no capslock */
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123 | #endif
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124 | };
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125 |
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126 | static const char opt_string[] ALIGN1 = "I:LH:f:hil:mt:wn";
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127 | #define F_INITSTRING (1 << 0) /* -I initstring is set */
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128 | #define F_LOCAL (1 << 1) /* -L force local */
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129 | #define F_FAKEHOST (1 << 2) /* -H fake hostname */
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130 | #define F_CUSTISSUE (1 << 3) /* -f give alternative issue file */
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131 | #define F_RTSCTS (1 << 4) /* -h enable RTS/CTS flow control */
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132 | #define F_ISSUE (1 << 5) /* -i display /etc/issue */
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133 | #define F_LOGIN (1 << 6) /* -l non-default login program */
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134 | #define F_PARSE (1 << 7) /* -m process modem status messages */
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135 | #define F_TIMEOUT (1 << 8) /* -t time out */
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136 | #define F_WAITCRLF (1 << 9) /* -w wait for CR or LF */
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137 | #define F_NOPROMPT (1 << 10) /* -n don't ask for login name */
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138 |
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139 |
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140 | #define line_buf bb_common_bufsiz1
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141 |
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142 | /* The following is used for understandable diagnostics. */
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143 | #ifdef DEBUGGING
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144 | static FILE *dbf;
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145 | #define DEBUGTERM "/dev/ttyp0"
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146 | #define debug(...) do { fprintf(dbf, __VA_ARGS__); fflush(dbf); } while (0)
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147 | #else
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148 | #define debug(...) ((void)0)
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149 | #endif
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150 |
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151 |
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152 | /* bcode - convert speed string to speed code; return <= 0 on failure */
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153 | static int bcode(const char *s)
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154 | {
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155 | int value = bb_strtou(s, NULL, 10); /* yes, int is intended! */
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156 | if (value < 0) /* bad terminating char, overflow, etc */
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157 | return value;
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158 | return tty_value_to_baud(value);
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159 | }
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160 |
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161 | /* parse_speeds - parse alternate baud rates */
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162 | static void parse_speeds(struct options *op, char *arg)
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163 | {
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164 | char *cp;
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165 |
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166 | /* NB: at least one iteration is always done */
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167 | debug("entered parse_speeds\n");
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168 | while ((cp = strsep(&arg, ",")) != NULL) {
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169 | op->speeds[op->numspeed] = bcode(cp);
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170 | if (op->speeds[op->numspeed] < 0)
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171 | bb_error_msg_and_die("bad speed: %s", cp);
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172 | /* note: arg "0" turns into speed B0 */
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173 | op->numspeed++;
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174 | if (op->numspeed > MAX_SPEED)
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175 | bb_error_msg_and_die("too many alternate speeds");
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176 | }
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177 | debug("exiting parse_speeds\n");
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178 | }
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179 |
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180 | /* parse_args - parse command-line arguments */
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181 | static void parse_args(char **argv, struct options *op, char **fakehost_p)
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182 | {
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183 | char *ts;
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184 |
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185 | opt_complementary = "-2:t+"; /* at least 2 args; -t N */
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186 | op->flags = getopt32(argv, opt_string,
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187 | &(op->initstring), fakehost_p, &(op->issue),
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188 | &(op->login), &op->timeout);
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189 | argv += optind;
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190 | if (op->flags & F_INITSTRING) {
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191 | op->initstring = xstrdup(op->initstring);
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192 | /* decode \ddd octal codes into chars */
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193 | strcpy_and_process_escape_sequences((char*)op->initstring, op->initstring);
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194 | }
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195 | op->flags ^= F_ISSUE; /* invert flag "show /etc/issue" */
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196 | debug("after getopt\n");
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197 |
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198 | /* we loosen up a bit and accept both "baudrate tty" and "tty baudrate" */
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199 | op->tty = argv[0]; /* tty name */
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200 | ts = argv[1]; /* baud rate(s) */
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201 | if (isdigit(argv[0][0])) {
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202 | /* a number first, assume it's a speed (BSD style) */
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203 | op->tty = ts; /* tty name is in argv[1] */
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204 | ts = argv[0]; /* baud rate(s) */
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205 | }
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206 | parse_speeds(op, ts);
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207 | applet_name = xasprintf("getty: %s", op->tty);
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208 |
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209 | if (argv[2])
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210 | xsetenv("TERM", argv[2]);
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211 |
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212 | debug("exiting parse_args\n");
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213 | }
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214 |
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215 | /* open_tty - set up tty as standard { input, output, error } */
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216 | static void open_tty(const char *tty)
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217 | {
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218 | /* Set up new standard input, unless we are given an already opened port. */
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219 | if (NOT_LONE_DASH(tty)) {
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220 | // struct stat st;
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221 | // int cur_dir_fd;
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222 | // int fd;
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223 |
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224 | /* Sanity checks... */
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225 | // cur_dir_fd = xopen(".", O_DIRECTORY | O_NONBLOCK);
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226 | // xchdir("/dev");
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227 | // xstat(tty, &st);
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228 | // if (!S_ISCHR(st.st_mode))
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229 | // bb_error_msg_and_die("not a character device");
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230 |
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231 | if (tty[0] != '/')
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232 | tty = xasprintf("/dev/%s", tty); /* will leak it */
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233 |
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234 | /* Open the tty as standard input. */
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235 | debug("open(2)\n");
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236 | close(0);
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237 | /*fd =*/ xopen(tty, O_RDWR | O_NONBLOCK); /* uses fd 0 */
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238 |
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239 | // /* Restore current directory */
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240 | // fchdir(cur_dir_fd);
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241 |
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242 | /* Open the tty as standard input, continued */
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243 | // xmove_fd(fd, 0);
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244 | // /* fd is >= cur_dir_fd, and cur_dir_fd gets closed too here: */
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245 | // while (fd > 2)
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246 | // close(fd--);
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247 |
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248 | /* Set proper protections and ownership. */
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249 | fchown(0, 0, 0); /* 0:0 */
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250 | fchmod(0, 0620); /* crw--w---- */
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251 | } else {
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252 | /*
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253 | * Standard input should already be connected to an open port. Make
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254 | * sure it is open for read/write.
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255 | */
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256 | if ((fcntl(0, F_GETFL) & O_RDWR) != O_RDWR)
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257 | bb_error_msg_and_die("stdin is not open for read/write");
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258 | }
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259 | }
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260 |
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261 | /* termios_init - initialize termios settings */
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262 | static void termios_init(struct termios *tp, int speed, struct options *op)
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263 | {
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264 | speed_t ispeed, ospeed;
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265 | /*
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266 | * Initial termios settings: 8-bit characters, raw-mode, blocking i/o.
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267 | * Special characters are set after we have read the login name; all
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268 | * reads will be done in raw mode anyway. Errors will be dealt with
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269 | * later on.
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270 | */
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271 | /* flush input and output queues, important for modems! */
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272 | tcflush(0, TCIOFLUSH);
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273 | ispeed = ospeed = speed;
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274 | if (speed == B0) {
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275 | /* Speed was specified as "0" on command line.
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276 | * Just leave it unchanged */
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277 | ispeed = cfgetispeed(tp);
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278 | ospeed = cfgetospeed(tp);
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279 | }
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280 | tp->c_cflag = CS8 | HUPCL | CREAD;
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281 | if (op->flags & F_LOCAL)
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282 | tp->c_cflag |= CLOCAL;
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283 | cfsetispeed(tp, ispeed);
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284 | cfsetospeed(tp, ospeed);
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285 |
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286 | tp->c_iflag = tp->c_lflag = 0;
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287 | tp->c_oflag = OPOST | ONLCR;
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288 | tp->c_cc[VMIN] = 1;
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289 | tp->c_cc[VTIME] = 0;
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290 | #ifdef __linux__
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291 | tp->c_line = 0;
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292 | #endif
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293 |
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294 | /* Optionally enable hardware flow control */
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295 | #ifdef CRTSCTS
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296 | if (op->flags & F_RTSCTS)
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297 | tp->c_cflag |= CRTSCTS;
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298 | #endif
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299 |
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300 | tcsetattr_stdin_TCSANOW(tp);
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301 |
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302 | debug("term_io 2\n");
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303 | }
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304 |
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305 | /* auto_baud - extract baud rate from modem status message */
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306 | static void auto_baud(char *buf, unsigned size_buf, struct termios *tp)
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307 | {
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308 | int speed;
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309 | int vmin;
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310 | unsigned iflag;
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311 | char *bp;
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312 | int nread;
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313 |
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314 | /*
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315 | * This works only if the modem produces its status code AFTER raising
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316 | * the DCD line, and if the computer is fast enough to set the proper
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317 | * baud rate before the message has gone by. We expect a message of the
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318 | * following format:
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319 | *
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320 | * <junk><number><junk>
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321 | *
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322 | * The number is interpreted as the baud rate of the incoming call. If the
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323 | * modem does not tell us the baud rate within one second, we will keep
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324 | * using the current baud rate. It is advisable to enable BREAK
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325 | * processing (comma-separated list of baud rates) if the processing of
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326 | * modem status messages is enabled.
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327 | */
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328 |
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329 | /*
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330 | * Use 7-bit characters, don't block if input queue is empty. Errors will
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331 | * be dealt with later on.
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332 | */
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333 | iflag = tp->c_iflag;
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334 | tp->c_iflag |= ISTRIP; /* enable 8th-bit stripping */
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335 | vmin = tp->c_cc[VMIN];
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336 | tp->c_cc[VMIN] = 0; /* don't block if queue empty */
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337 | tcsetattr_stdin_TCSANOW(tp);
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338 |
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339 | /*
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340 | * Wait for a while, then read everything the modem has said so far and
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341 | * try to extract the speed of the dial-in call.
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342 | */
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343 | sleep(1);
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344 | nread = safe_read(STDIN_FILENO, buf, size_buf - 1);
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345 | if (nread > 0) {
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346 | buf[nread] = '\0';
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347 | for (bp = buf; bp < buf + nread; bp++) {
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348 | if (isdigit(*bp)) {
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349 | speed = bcode(bp);
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350 | if (speed > 0)
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351 | cfsetspeed(tp, speed);
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352 | break;
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353 | }
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354 | }
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355 | }
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356 |
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357 | /* Restore terminal settings. Errors will be dealt with later on. */
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358 | tp->c_iflag = iflag;
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359 | tp->c_cc[VMIN] = vmin;
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360 | tcsetattr_stdin_TCSANOW(tp);
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361 | }
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362 |
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363 | /* do_prompt - show login prompt, optionally preceded by /etc/issue contents */
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364 | static void do_prompt(struct options *op)
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365 | {
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366 | #ifdef ISSUE
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367 | print_login_issue(op->issue, op->tty);
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368 | #endif
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369 | print_login_prompt();
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370 | }
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371 |
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372 | #ifdef HANDLE_ALLCAPS
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373 | /* all_is_upcase - string contains upper case without lower case */
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374 | /* returns 1 if true, 0 if false */
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375 | static int all_is_upcase(const char *s)
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376 | {
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377 | while (*s)
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378 | if (islower(*s++))
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379 | return 0;
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380 | return 1;
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381 | }
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382 | #endif
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383 |
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384 | /* get_logname - get user name, establish parity, speed, erase, kill, eol;
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385 | * return NULL on BREAK, logname on success */
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386 | static char *get_logname(char *logname, unsigned size_logname,
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387 | struct options *op, struct chardata *cp)
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388 | {
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389 | char *bp;
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390 | char c; /* input character, full eight bits */
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391 | char ascval; /* low 7 bits of input character */
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392 | int bits; /* # of "1" bits per character */
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393 | int mask; /* mask with 1 bit up */
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394 | static const char erase[][3] = {/* backspace-space-backspace */
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395 | "\010\040\010", /* space parity */
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396 | "\010\040\010", /* odd parity */
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397 | "\210\240\210", /* even parity */
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398 | "\010\040\010", /* 8 bit no parity */
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399 | };
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400 |
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401 | /* NB: *cp is pre-initialized with init_chardata */
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402 |
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403 | /* Flush pending input (esp. after parsing or switching the baud rate). */
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404 | sleep(1);
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405 | tcflush(0, TCIOFLUSH);
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406 |
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407 | /* Prompt for and read a login name. */
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408 | logname[0] = '\0';
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409 | while (!logname[0]) {
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410 | /* Write issue file and prompt, with "parity" bit == 0. */
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411 | do_prompt(op);
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412 |
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413 | /* Read name, watch for break, parity, erase, kill, end-of-line. */
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414 | bp = logname;
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415 | cp->eol = '\0';
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416 | while (cp->eol == '\0') {
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417 |
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418 | /* Do not report trivial EINTR/EIO errors. */
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419 | errno = EINTR; /* make read of 0 bytes be silent too */
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420 | if (read(STDIN_FILENO, &c, 1) < 1) {
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421 | if (errno == EINTR || errno == EIO)
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422 | exit(EXIT_SUCCESS);
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423 | bb_perror_msg_and_die(bb_msg_read_error);
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424 | }
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425 |
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426 | /* BREAK. If we have speeds to try,
|
---|
427 | * return NULL (will switch speeds and return here) */
|
---|
428 | if (c == '\0' && op->numspeed > 1)
|
---|
429 | return NULL;
|
---|
430 |
|
---|
431 | /* Do parity bit handling. */
|
---|
432 | if (!(op->flags & F_LOCAL) && (c & 0x80)) { /* "parity" bit on? */
|
---|
433 | bits = 1;
|
---|
434 | mask = 1;
|
---|
435 | while (mask & 0x7f) {
|
---|
436 | if (mask & c)
|
---|
437 | bits++; /* count "1" bits */
|
---|
438 | mask <<= 1;
|
---|
439 | }
|
---|
440 | /* ... |= 2 - even, 1 - odd */
|
---|
441 | cp->parity |= 2 - (bits & 1);
|
---|
442 | }
|
---|
443 |
|
---|
444 | /* Do erase, kill and end-of-line processing. */
|
---|
445 | ascval = c & 0x7f;
|
---|
446 | switch (ascval) {
|
---|
447 | case CR:
|
---|
448 | case NL:
|
---|
449 | *bp = '\0'; /* terminate logname */
|
---|
450 | cp->eol = ascval; /* set end-of-line char */
|
---|
451 | break;
|
---|
452 | case BS:
|
---|
453 | case DEL:
|
---|
454 | #ifdef ANCIENT_BS_KILL_CHARS
|
---|
455 | case '#':
|
---|
456 | #endif
|
---|
457 | cp->erase = ascval; /* set erase character */
|
---|
458 | if (bp > logname) {
|
---|
459 | full_write(STDOUT_FILENO, erase[cp->parity], 3);
|
---|
460 | bp--;
|
---|
461 | }
|
---|
462 | break;
|
---|
463 | case CTL('U'):
|
---|
464 | #ifdef ANCIENT_BS_KILL_CHARS
|
---|
465 | case '@':
|
---|
466 | #endif
|
---|
467 | cp->kill = ascval; /* set kill character */
|
---|
468 | while (bp > logname) {
|
---|
469 | full_write(STDOUT_FILENO, erase[cp->parity], 3);
|
---|
470 | bp--;
|
---|
471 | }
|
---|
472 | break;
|
---|
473 | case CTL('D'):
|
---|
474 | exit(EXIT_SUCCESS);
|
---|
475 | default:
|
---|
476 | if (ascval < ' ') {
|
---|
477 | /* ignore garbage characters */
|
---|
478 | } else if ((int)(bp - logname) >= size_logname - 1) {
|
---|
479 | bb_error_msg_and_die("input overrun");
|
---|
480 | } else {
|
---|
481 | full_write(STDOUT_FILENO, &c, 1); /* echo the character */
|
---|
482 | *bp++ = ascval; /* and store it */
|
---|
483 | }
|
---|
484 | break;
|
---|
485 | }
|
---|
486 | }
|
---|
487 | }
|
---|
488 | /* Handle names with upper case and no lower case. */
|
---|
489 |
|
---|
490 | #ifdef HANDLE_ALLCAPS
|
---|
491 | cp->capslock = all_is_upcase(logname);
|
---|
492 | if (cp->capslock) {
|
---|
493 | for (bp = logname; *bp; bp++)
|
---|
494 | if (isupper(*bp))
|
---|
495 | *bp = tolower(*bp); /* map name to lower case */
|
---|
496 | }
|
---|
497 | #endif
|
---|
498 | return logname;
|
---|
499 | }
|
---|
500 |
|
---|
501 | /* termios_final - set the final tty mode bits */
|
---|
502 | static void termios_final(struct options *op, struct termios *tp, struct chardata *cp)
|
---|
503 | {
|
---|
504 | /* General terminal-independent stuff. */
|
---|
505 | tp->c_iflag |= IXON | IXOFF; /* 2-way flow control */
|
---|
506 | tp->c_lflag |= ICANON | ISIG | ECHO | ECHOE | ECHOK | ECHOKE;
|
---|
507 | /* no longer| ECHOCTL | ECHOPRT */
|
---|
508 | tp->c_oflag |= OPOST;
|
---|
509 | /* tp->c_cflag = 0; */
|
---|
510 | tp->c_cc[VINTR] = DEF_INTR; /* default interrupt */
|
---|
511 | tp->c_cc[VQUIT] = DEF_QUIT; /* default quit */
|
---|
512 | tp->c_cc[VEOF] = DEF_EOF; /* default EOF character */
|
---|
513 | tp->c_cc[VEOL] = DEF_EOL;
|
---|
514 | #ifdef VSWTC
|
---|
515 | tp->c_cc[VSWTC] = DEF_SWITCH; /* default switch character */
|
---|
516 | #endif
|
---|
517 |
|
---|
518 | /* Account for special characters seen in input. */
|
---|
519 | if (cp->eol == CR) {
|
---|
520 | tp->c_iflag |= ICRNL; /* map CR in input to NL */
|
---|
521 | tp->c_oflag |= ONLCR; /* map NL in output to CR-NL */
|
---|
522 | }
|
---|
523 | tp->c_cc[VERASE] = cp->erase; /* set erase character */
|
---|
524 | tp->c_cc[VKILL] = cp->kill; /* set kill character */
|
---|
525 |
|
---|
526 | /* Account for the presence or absence of parity bits in input. */
|
---|
527 | switch (cp->parity) {
|
---|
528 | case 0: /* space (always 0) parity */
|
---|
529 | // I bet most people go here - they use only 7-bit chars in usernames....
|
---|
530 | break;
|
---|
531 | case 1: /* odd parity */
|
---|
532 | tp->c_cflag |= PARODD;
|
---|
533 | /* FALLTHROUGH */
|
---|
534 | case 2: /* even parity */
|
---|
535 | tp->c_cflag |= PARENB;
|
---|
536 | tp->c_iflag |= INPCK | ISTRIP;
|
---|
537 | /* FALLTHROUGH */
|
---|
538 | case (1 | 2): /* no parity bit */
|
---|
539 | tp->c_cflag &= ~CSIZE;
|
---|
540 | tp->c_cflag |= CS7;
|
---|
541 | // FIXME: wtf? case 3: we saw both even and odd 8-bit bytes -
|
---|
542 | // it's probably some umlauts etc, but definitely NOT 7-bit!!!
|
---|
543 | // Entire parity detection madness here just begs for deletion...
|
---|
544 | break;
|
---|
545 | }
|
---|
546 |
|
---|
547 | /* Account for upper case without lower case. */
|
---|
548 | #ifdef HANDLE_ALLCAPS
|
---|
549 | if (cp->capslock) {
|
---|
550 | tp->c_iflag |= IUCLC;
|
---|
551 | tp->c_lflag |= XCASE;
|
---|
552 | tp->c_oflag |= OLCUC;
|
---|
553 | }
|
---|
554 | #endif
|
---|
555 | /* Optionally enable hardware flow control */
|
---|
556 | #ifdef CRTSCTS
|
---|
557 | if (op->flags & F_RTSCTS)
|
---|
558 | tp->c_cflag |= CRTSCTS;
|
---|
559 | #endif
|
---|
560 |
|
---|
561 | /* Finally, make the new settings effective */
|
---|
562 | if (tcsetattr_stdin_TCSANOW(tp) < 0)
|
---|
563 | bb_perror_msg_and_die("tcsetattr");
|
---|
564 | }
|
---|
565 |
|
---|
566 | int getty_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
---|
567 | int getty_main(int argc UNUSED_PARAM, char **argv)
|
---|
568 | {
|
---|
569 | int n;
|
---|
570 | pid_t pid;
|
---|
571 | char *fakehost = NULL; /* Fake hostname for ut_host */
|
---|
572 | char *logname; /* login name, given to /bin/login */
|
---|
573 | /* Merging these into "struct local" may _seem_ to reduce
|
---|
574 | * parameter passing, but today's gcc will inline
|
---|
575 | * statics which are called once anyway, so don't do that */
|
---|
576 | struct chardata chardata; /* set by get_logname() */
|
---|
577 | struct termios termios; /* terminal mode bits */
|
---|
578 | struct options options;
|
---|
579 |
|
---|
580 | chardata = init_chardata;
|
---|
581 |
|
---|
582 | memset(&options, 0, sizeof(options));
|
---|
583 | options.login = _PATH_LOGIN; /* default login program */
|
---|
584 | options.tty = "tty1"; /* default tty line */
|
---|
585 | options.initstring = ""; /* modem init string */
|
---|
586 | #ifdef ISSUE
|
---|
587 | options.issue = ISSUE; /* default issue file */
|
---|
588 | #endif
|
---|
589 |
|
---|
590 | /* Parse command-line arguments. */
|
---|
591 | parse_args(argv, &options, &fakehost);
|
---|
592 |
|
---|
593 | logmode = LOGMODE_NONE;
|
---|
594 |
|
---|
595 | /* Create new session, lose controlling tty, if any */
|
---|
596 | /* docs/ctty.htm says:
|
---|
597 | * "This is allowed only when the current process
|
---|
598 | * is not a process group leader" - is this a problem? */
|
---|
599 | setsid();
|
---|
600 | /* close stdio, and stray descriptors, just in case */
|
---|
601 | n = xopen(bb_dev_null, O_RDWR);
|
---|
602 | /* dup2(n, 0); - no, we need to handle "getty - 9600" too */
|
---|
603 | xdup2(n, 1);
|
---|
604 | xdup2(n, 2);
|
---|
605 | while (n > 2)
|
---|
606 | close(n--);
|
---|
607 |
|
---|
608 | /* Logging. We want special flavor of error_msg_and_die */
|
---|
609 | die_sleep = 10;
|
---|
610 | msg_eol = "\r\n";
|
---|
611 | /* most likely will internally use fd #3 in CLOEXEC mode: */
|
---|
612 | openlog(applet_name, LOG_PID, LOG_AUTH);
|
---|
613 | logmode = LOGMODE_BOTH;
|
---|
614 |
|
---|
615 | #ifdef DEBUGGING
|
---|
616 | dbf = xfopen_for_write(DEBUGTERM);
|
---|
617 | for (n = 1; argv[n]; n++) {
|
---|
618 | debug(argv[n]);
|
---|
619 | debug("\n");
|
---|
620 | }
|
---|
621 | #endif
|
---|
622 |
|
---|
623 | /* Open the tty as standard input, if it is not "-" */
|
---|
624 | /* If it's not "-" and not taken yet, it will become our ctty */
|
---|
625 | debug("calling open_tty\n");
|
---|
626 | open_tty(options.tty);
|
---|
627 | ndelay_off(0);
|
---|
628 | debug("duping\n");
|
---|
629 | xdup2(0, 1);
|
---|
630 | xdup2(0, 2);
|
---|
631 |
|
---|
632 | /*
|
---|
633 | * The following ioctl will fail if stdin is not a tty, but also when
|
---|
634 | * there is noise on the modem control lines. In the latter case, the
|
---|
635 | * common course of action is (1) fix your cables (2) give the modem more
|
---|
636 | * time to properly reset after hanging up. SunOS users can achieve (2)
|
---|
637 | * by patching the SunOS kernel variable "zsadtrlow" to a larger value;
|
---|
638 | * 5 seconds seems to be a good value.
|
---|
639 | */
|
---|
640 | if (tcgetattr(0, &termios) < 0)
|
---|
641 | bb_perror_msg_and_die("tcgetattr");
|
---|
642 |
|
---|
643 | pid = getpid();
|
---|
644 | #ifdef __linux__
|
---|
645 | // FIXME: do we need this? Otherwise "-" case seems to be broken...
|
---|
646 | // /* Forcibly make fd 0 our controlling tty, even if another session
|
---|
647 | // * has it as a ctty. (Another session loses ctty). */
|
---|
648 | // ioctl(0, TIOCSCTTY, (void*)1);
|
---|
649 | /* Make ourself a foreground process group within our session */
|
---|
650 | tcsetpgrp(0, pid);
|
---|
651 | #endif
|
---|
652 |
|
---|
653 | /* Update the utmp file. This tty is ours now! */
|
---|
654 | update_utmp(pid, LOGIN_PROCESS, options.tty, "LOGIN", fakehost);
|
---|
655 |
|
---|
656 | /* Initialize the termios settings (raw mode, eight-bit, blocking i/o). */
|
---|
657 | debug("calling termios_init\n");
|
---|
658 | termios_init(&termios, options.speeds[0], &options);
|
---|
659 |
|
---|
660 | /* Write the modem init string and DON'T flush the buffers */
|
---|
661 | if (options.flags & F_INITSTRING) {
|
---|
662 | debug("writing init string\n");
|
---|
663 | full_write1_str(options.initstring);
|
---|
664 | }
|
---|
665 |
|
---|
666 | /* Optionally detect the baud rate from the modem status message */
|
---|
667 | debug("before autobaud\n");
|
---|
668 | if (options.flags & F_PARSE)
|
---|
669 | auto_baud(line_buf, sizeof(line_buf), &termios);
|
---|
670 |
|
---|
671 | /* Set the optional timer */
|
---|
672 | alarm(options.timeout); /* if 0, alarm is not set */
|
---|
673 |
|
---|
674 | /* Optionally wait for CR or LF before writing /etc/issue */
|
---|
675 | if (options.flags & F_WAITCRLF) {
|
---|
676 | char ch;
|
---|
677 |
|
---|
678 | debug("waiting for cr-lf\n");
|
---|
679 | while (safe_read(STDIN_FILENO, &ch, 1) == 1) {
|
---|
680 | debug("read %x\n", (unsigned char)ch);
|
---|
681 | ch &= 0x7f; /* strip "parity bit" */
|
---|
682 | if (ch == '\n' || ch == '\r')
|
---|
683 | break;
|
---|
684 | }
|
---|
685 | }
|
---|
686 |
|
---|
687 | logname = NULL;
|
---|
688 | if (!(options.flags & F_NOPROMPT)) {
|
---|
689 | /* NB:termios_init already set line speed
|
---|
690 | * to options.speeds[0] */
|
---|
691 | int baud_index = 0;
|
---|
692 |
|
---|
693 | while (1) {
|
---|
694 | /* Read the login name. */
|
---|
695 | debug("reading login name\n");
|
---|
696 | logname = get_logname(line_buf, sizeof(line_buf),
|
---|
697 | &options, &chardata);
|
---|
698 | if (logname)
|
---|
699 | break;
|
---|
700 | /* we are here only if options.numspeed > 1 */
|
---|
701 | baud_index = (baud_index + 1) % options.numspeed;
|
---|
702 | cfsetispeed(&termios, options.speeds[baud_index]);
|
---|
703 | cfsetospeed(&termios, options.speeds[baud_index]);
|
---|
704 | tcsetattr_stdin_TCSANOW(&termios);
|
---|
705 | }
|
---|
706 | }
|
---|
707 |
|
---|
708 | /* Disable timer. */
|
---|
709 | alarm(0);
|
---|
710 |
|
---|
711 | /* Finalize the termios settings. */
|
---|
712 | termios_final(&options, &termios, &chardata);
|
---|
713 |
|
---|
714 | /* Now the newline character should be properly written. */
|
---|
715 | full_write(STDOUT_FILENO, "\n", 1);
|
---|
716 |
|
---|
717 | /* Let the login program take care of password validation. */
|
---|
718 | /* We use PATH because we trust that root doesn't set "bad" PATH,
|
---|
719 | * and getty is not suid-root applet. */
|
---|
720 | /* With -n, logname == NULL, and login will ask for username instead */
|
---|
721 | BB_EXECLP(options.login, options.login, "--", logname, NULL);
|
---|
722 | bb_error_msg_and_die("can't execute '%s'", options.login);
|
---|
723 | }
|
---|