blob: 5a7acfcf058c192413b516227f22add01b7eb727
| 1 | /* vi: set sw=4 ts=4: */ |
| 2 | /* |
| 3 | * issue.c: issue printing code |
| 4 | * |
| 5 | * Copyright (C) 2003 Bastian Blank <waldi@tuxbox.org> |
| 6 | * |
| 7 | * Optimize and correcting OCRNL by Vladimir Oleynik <dzo@simtreas.ru> |
| 8 | * |
| 9 | * Licensed under GPLv2 or later, see file LICENSE in this source tree. |
| 10 | */ |
| 11 | |
| 12 | #include "libbb.h" |
| 13 | /* After libbb.h, since it needs sys/types.h on some systems */ |
| 14 | #include <sys/utsname.h> |
| 15 | |
| 16 | #define LOGIN " login: " |
| 17 | |
| 18 | static const char fmtstr_d[] ALIGN1 = "%A, %d %B %Y"; |
| 19 | |
| 20 | void FAST_FUNC print_login_issue(const char *issue_file, const char *tty) |
| 21 | { |
| 22 | FILE *fp; |
| 23 | int c; |
| 24 | char buf[256+1]; |
| 25 | const char *outbuf; |
| 26 | time_t t; |
| 27 | struct utsname uts; |
| 28 | |
| 29 | time(&t); |
| 30 | uname(&uts); |
| 31 | |
| 32 | puts("\r"); /* start a new line */ |
| 33 | |
| 34 | fp = fopen_for_read(issue_file); |
| 35 | if (!fp) |
| 36 | return; |
| 37 | while ((c = fgetc(fp)) != EOF) { |
| 38 | outbuf = buf; |
| 39 | buf[0] = c; |
| 40 | buf[1] = '\0'; |
| 41 | if (c == '\n') { |
| 42 | buf[1] = '\r'; |
| 43 | buf[2] = '\0'; |
| 44 | } |
| 45 | if (c == '\\' || c == '%') { |
| 46 | c = fgetc(fp); |
| 47 | switch (c) { |
| 48 | //From getty manpage (* - supported by us) |
| 49 | //======================================== |
| 50 | //4 or 4{interface} |
| 51 | // Insert the IPv4 address of the network interface (example: \4{eth0}). |
| 52 | // If the interface argument is not specified, then select the first |
| 53 | // fully configured (UP, non-LOOPBACK, RUNNING) interface. |
| 54 | //6 or 6{interface} -- The same as \4 but for IPv6. |
| 55 | //b -- Insert the baudrate of the current line. |
| 56 | //*d -- Insert the current date. |
| 57 | //*t -- Insert the current time. |
| 58 | //e or e{name} |
| 59 | // Translate the human-readable name to an escape sequence and insert it |
| 60 | // (for example: \e{red}Alert text.\e{reset}). If the name argument |
| 61 | // is not specified, then insert \033. The currently supported names are: |
| 62 | // black, blink, blue, bold, brown, cyan, darkgray, gray, green, halfbright, |
| 63 | // lightblue, lightcyan, lightgray, lightgreen, lightmagenta, lightred, |
| 64 | // magenta, red, reset, reverse, and yellow. Unknown names are ignored. |
| 65 | //*s |
| 66 | // Insert the system name (the name of the operating system - `uname -s`) |
| 67 | //*S or S{VARIABLE} |
| 68 | // Insert the VARIABLE data from /etc/os-release. |
| 69 | // If the VARIABLE argument is not specified, use PRETTY_NAME. |
| 70 | // If PRETTY_NAME is not in /etc/os-release, \S is the same as \s. |
| 71 | //*l -- Insert the name of the current tty line. |
| 72 | //*m -- Insert the architecture identifier of the machine: `uname -m`. |
| 73 | //*n -- Insert the nodename of the machine: `uname -n`. |
| 74 | //*o -- Insert the NIS domainname of the machine. Same as `hostname -d'. |
| 75 | //*O -- Insert the DNS domainname of the machine. |
| 76 | //*r -- Insert the release number of the OS: `uname -r`. |
| 77 | //u -- Insert the number of current users logged in. |
| 78 | //U -- Insert the string "1 user" or "N users" (current users logged in). |
| 79 | //*v -- Insert the version of the OS, e.g. the build-date etc: `uname -v`. |
| 80 | //We also implement: |
| 81 | //*D -- same as \O "DNS domainname" |
| 82 | //*h -- same as \n "nodename" |
| 83 | |
| 84 | case 'S': |
| 85 | /* minimal implementation, not reading /etc/os-release */ |
| 86 | /*FALLTHROUGH*/ |
| 87 | case 's': |
| 88 | outbuf = uts.sysname; |
| 89 | break; |
| 90 | case 'n': |
| 91 | case 'h': |
| 92 | outbuf = uts.nodename; |
| 93 | break; |
| 94 | case 'r': |
| 95 | outbuf = uts.release; |
| 96 | break; |
| 97 | case 'v': |
| 98 | outbuf = uts.version; |
| 99 | break; |
| 100 | case 'm': |
| 101 | outbuf = uts.machine; |
| 102 | break; |
| 103 | /* The field domainname of struct utsname is Linux specific. */ |
| 104 | #if defined(__linux__) |
| 105 | case 'D': |
| 106 | case 'o': |
| 107 | case 'O': |
| 108 | outbuf = uts.domainname; |
| 109 | break; |
| 110 | #endif |
| 111 | case 'd': |
| 112 | strftime(buf, sizeof(buf), fmtstr_d, localtime(&t)); |
| 113 | break; |
| 114 | case 't': |
| 115 | strftime_HHMMSS(buf, sizeof(buf), &t); |
| 116 | break; |
| 117 | case 'l': |
| 118 | outbuf = tty; |
| 119 | break; |
| 120 | default: |
| 121 | buf[0] = c; |
| 122 | } |
| 123 | } |
| 124 | fputs(outbuf, stdout); |
| 125 | } |
| 126 | fclose(fp); |
| 127 | fflush_all(); |
| 128 | } |
| 129 | |
| 130 | void FAST_FUNC print_login_prompt(void) |
| 131 | { |
| 132 | char *hostname = safe_gethostname(); |
| 133 | |
| 134 | fputs(hostname, stdout); |
| 135 | fputs(LOGIN, stdout); |
| 136 | fflush_all(); |
| 137 | free(hostname); |
| 138 | } |
| 139 | |
| 140 | /* Clear dangerous stuff, set PATH */ |
| 141 | static const char forbid[] ALIGN1 = |
| 142 | "ENV" "\0" |
| 143 | "BASH_ENV" "\0" |
| 144 | "HOME" "\0" |
| 145 | "IFS" "\0" |
| 146 | "SHELL" "\0" |
| 147 | "LD_LIBRARY_PATH" "\0" |
| 148 | "LD_PRELOAD" "\0" |
| 149 | "LD_TRACE_LOADED_OBJECTS" "\0" |
| 150 | "LD_BIND_NOW" "\0" |
| 151 | "LD_AOUT_LIBRARY_PATH" "\0" |
| 152 | "LD_AOUT_PRELOAD" "\0" |
| 153 | "LD_NOWARN" "\0" |
| 154 | "LD_KEEPDIR" "\0"; |
| 155 | |
| 156 | int FAST_FUNC sanitize_env_if_suid(void) |
| 157 | { |
| 158 | const char *p; |
| 159 | |
| 160 | if (getuid() == geteuid()) |
| 161 | return 0; |
| 162 | |
| 163 | p = forbid; |
| 164 | do { |
| 165 | unsetenv(p); |
| 166 | p += strlen(p) + 1; |
| 167 | } while (*p); |
| 168 | putenv((char*)bb_PATH_root_path); |
| 169 | |
| 170 | return 1; /* we indeed were run by different user! */ |
| 171 | } |
| 172 |