blob: 7f593d80d61964b06cbffbc2f8846dc8aa1bd27a [file] [log] [blame]
/* vi: set sw=4 ts=4: */
* issue.c: issue printing code
* Copyright (C) 2003 Bastian Blank <>
* Optimize and correcting OCRNL by Vladimir Oleynik <>
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
#include "libbb.h"
/* After libbb.h, since it needs sys/types.h on some systems */
#include <sys/utsname.h>
#define LOGIN " login: "
static const char fmtstr_d[] ALIGN1 = "%A, %d %B %Y";
void FAST_FUNC print_login_issue(const char *issue_file, const char *tty)
FILE *fp;
int c;
char buf[256+1];
const char *outbuf;
time_t t;
struct utsname uts;
puts("\r"); /* start a new line */
fp = fopen_for_read(issue_file);
if (!fp)
while ((c = fgetc(fp)) != EOF) {
outbuf = buf;
buf[0] = c;
buf[1] = '\0';
if (c == '\n') {
buf[1] = '\r';
buf[2] = '\0';
if (c == '\\' || c == '%') {
c = fgetc(fp);
switch (c) {
//From getty manpage (* - supported by us)
//4 or 4{interface}
// Insert the IPv4 address of the network interface (example: \4{eth0}).
// If the interface argument is not specified, then select the first
// fully configured (UP, non-LOOPBACK, RUNNING) interface.
//6 or 6{interface} -- The same as \4 but for IPv6.
//b -- Insert the baudrate of the current line.
//*d -- Insert the current date.
//*t -- Insert the current time.
//e or e{name}
// Translate the human-readable name to an escape sequence and insert it
// (for example: \e{red}Alert text.\e{reset}). If the name argument
// is not specified, then insert \033. The currently supported names are:
// black, blink, blue, bold, brown, cyan, darkgray, gray, green, halfbright,
// lightblue, lightcyan, lightgray, lightgreen, lightmagenta, lightred,
// magenta, red, reset, reverse, and yellow. Unknown names are ignored.
// Insert the system name (the name of the operating system - `uname -s`)
// Insert the VARIABLE data from /etc/os-release.
// If the VARIABLE argument is not specified, use PRETTY_NAME.
// If PRETTY_NAME is not in /etc/os-release, \S is the same as \s.
//*l -- Insert the name of the current tty line.
//*m -- Insert the architecture identifier of the machine: `uname -m`.
//*n -- Insert the nodename of the machine: `uname -n`.
//*o -- Insert the NIS domainname of the machine. Same as `hostname -d'.
//*O -- Insert the DNS domainname of the machine.
//*r -- Insert the release number of the OS: `uname -r`.
//u -- Insert the number of current users logged in.
//U -- Insert the string "1 user" or "N users" (current users logged in).
//*v -- Insert the version of the OS, e.g. the build-date etc: `uname -v`.
//We also implement:
//*D -- same as \O "DNS domainname"
//*h -- same as \n "nodename"
case 'S':
/* minimal implementation, not reading /etc/os-release */
case 's':
outbuf = uts.sysname;
case 'n':
case 'h':
outbuf = uts.nodename;
case 'r':
outbuf = uts.release;
case 'v':
outbuf = uts.version;
case 'm':
outbuf = uts.machine;
/* The field domainname of struct utsname is Linux specific. */
#if defined(__linux__)
case 'D':
case 'o':
case 'O':
outbuf = uts.domainname;
case 'd':
strftime(buf, sizeof(buf), fmtstr_d, localtime(&t));
case 't':
strftime_HHMMSS(buf, sizeof(buf), &t);
case 'l':
outbuf = tty;
buf[0] = c;
fputs(outbuf, stdout);
void FAST_FUNC print_login_prompt(void)
char *hostname = safe_gethostname();
fputs(hostname, stdout);
fputs(LOGIN, stdout);
/* Clear dangerous stuff, set PATH */
static const char forbid[] ALIGN1 =
"ENV" "\0"
"BASH_ENV" "\0"
"HOME" "\0"
"IFS" "\0"
"SHELL" "\0"
"LD_BIND_NOW" "\0"
"LD_NOWARN" "\0"
"LD_KEEPDIR" "\0";
int FAST_FUNC sanitize_env_if_suid(void)
const char *p;
if (getuid() == geteuid())
return 0;
p = forbid;
do {
p += strlen(p) + 1;
} while (*p);
return 1; /* we indeed were run by different user! */