diff options
| -rw-r--r-- | loginutils/login.c | 357 |
1 files changed, 166 insertions, 191 deletions
diff --git a/loginutils/login.c b/loginutils/login.c index 2c23a8d50..78a2ba117 100644 --- a/loginutils/login.c +++ b/loginutils/login.c @@ -15,13 +15,6 @@ #include <errno.h> #endif -/* import from utmp.c - * XXX: FIXME: provide empty bodies if ENABLE_FEATURE_UTMP == 0 - */ -static struct utmp utent; -static void read_or_build_utent(int); -static void write_utent(const char *); - enum { TIMEOUT = 60, EMPTY_USERNAME_COUNT = 10, @@ -29,16 +22,176 @@ enum { TTYNAME_SIZE = 32, }; -static void die_if_nologin_and_non_root(int amroot); +static char full_tty[TTYNAME_SIZE]; +static char* short_tty = full_tty; + +#if ENABLE_FEATURE_UTMP +/* vv Taken from tinylogin utmp.c vv */ +/* + * read_or_build_utent - see if utmp file is correct for this process + * + * System V is very picky about the contents of the utmp file + * and requires that a slot for the current process exist. + * The utmp file is scanned for an entry with the same process + * ID. If no entry exists the process exits with a message. + * + * The "picky" flag is for network and other logins that may + * use special flags. It allows the pid checks to be overridden. + * This means that getty should never invoke login with any + * command line flags. + */ +static struct utmp utent; +static void read_or_build_utent(int picky) +{ + struct utmp *ut; + pid_t pid = getpid(); + + setutent(); + + /* First, try to find a valid utmp entry for this process. */ + while ((ut = getutent())) + if (ut->ut_pid == pid && ut->ut_line[0] && ut->ut_id[0] && + (ut->ut_type == LOGIN_PROCESS || ut->ut_type == USER_PROCESS)) + break; + + /* If there is one, just use it, otherwise create a new one. */ + if (ut) { + utent = *ut; + } else { + if (picky) + bb_error_msg_and_die("no utmp entry found"); + + memset(&utent, 0, sizeof(utent)); + utent.ut_type = LOGIN_PROCESS; + utent.ut_pid = pid; + strncpy(utent.ut_line, short_tty, sizeof(utent.ut_line)); + /* This one is only 4 chars wide. Try to fit something + * remotely meaningful by skipping "tty"... */ + strncpy(utent.ut_id, short_tty + 3, sizeof(utent.ut_id)); + strncpy(utent.ut_user, "LOGIN", sizeof(utent.ut_user)); + utent.ut_time = time(NULL); + } + if (!picky) /* root login */ + memset(utent.ut_host, 0, sizeof(utent.ut_host)); +} + +/* + * write_utent - put a USER_PROCESS entry in the utmp file + * + * write_utent changes the type of the current utmp entry to + * USER_PROCESS. the wtmp file will be updated as well. + */ +static void write_utent(const char *username) +{ + utent.ut_type = USER_PROCESS; + strncpy(utent.ut_user, username, sizeof(utent.ut_user)); + utent.ut_time = time(NULL); + /* other fields already filled in by read_or_build_utent above */ + setutent(); + pututline(&utent); + endutent(); +#if ENABLE_FEATURE_WTMP + if (access(bb_path_wtmp_file, R_OK|W_OK) == -1) { + close(creat(bb_path_wtmp_file, 0664)); + } + updwtmp(bb_path_wtmp_file, &utent); +#endif +} +#else /* !CONFIG_FEATURE_UTMP */ +static inline void read_or_build_utent(int) {} +static inline void write_utent(const char *) {} +#endif /* !CONFIG_FEATURE_UTMP */ + +static void die_if_nologin_and_non_root(int amroot) +{ + FILE *fp; + int c; + + if (access(bb_path_nologin_file, F_OK)) + return; + + fp = fopen(bb_path_nologin_file, "r"); + if (fp) { + while ((c = getc(fp)) != EOF) + putchar((c=='\n') ? '\r' : c); + fflush(stdout); + fclose(fp); + } else + puts("\r\nSystem closed for routine maintenance\r"); + if (!amroot) + exit(1); + puts("\r\n[Disconnect bypassed -- root login allowed.]\r"); +} #if ENABLE_FEATURE_SECURETTY -static int check_securetty(void); +static int check_securetty(void) +{ + FILE *fp; + int i; + char buf[BUFSIZ]; + + fp = fopen(bb_path_securetty_file, "r"); + if (!fp) { + /* A missing securetty file is not an error. */ + return 1; + } + while (fgets(buf, sizeof(buf)-1, fp)) { + for(i = strlen(buf)-1; i>=0; --i) { + if (!isspace(buf[i])) + break; + } + buf[++i] = '\0'; + if ((buf[0]=='\0') || (buf[0]=='#')) + continue; + if (strcmp(buf, short_tty) == 0) { + fclose(fp); + return 1; + } + } + fclose(fp); + return 0; +} #else static inline int check_securetty(void) { return 1; } #endif -static void get_username_or_die(char *buf, int size_buf); -static void motd(void); +static void get_username_or_die(char *buf, int size_buf) +{ + int c, cntdown; + cntdown = EMPTY_USERNAME_COUNT; +prompt: + /* skip whitespace */ + print_login_prompt(); + do { + c = getchar(); + if (c == EOF) exit(1); + if (c == '\n') { + if (!--cntdown) exit(1); + goto prompt; + } + } while (isspace(c)); + + *buf++ = c; + if (!fgets(buf, size_buf-2, stdin)) + exit(1); + if (!strchr(buf, '\n')) + exit(1); + while (isgraph(*buf)) buf++; + *buf = '\0'; +} + +static void motd(void) +{ + FILE *fp; + int c; + + fp = fopen(bb_path_motd_file, "r"); + if (fp) { + while ((c = getc(fp)) != EOF) + putchar(c); + fclose(fp); + } +} static void nonblock(int fd) { @@ -56,11 +209,6 @@ static void alarm_handler(int sig ATTRIBUTE_UNUSED) exit(EXIT_SUCCESS); } - -static char full_tty[TTYNAME_SIZE]; -static char* short_tty = full_tty; - - int login_main(int argc, char **argv) { char fromhost[512]; @@ -122,11 +270,7 @@ int login_main(int argc, char **argv) short_tty = full_tty + 5; } - if (ENABLE_FEATURE_UTMP) { - read_or_build_utent(!amroot); - if (amroot) - memset(utent.ut_host, 0, sizeof(utent.ut_host)); - } + read_or_build_utent(!amroot); if (opt_host) { if (ENABLE_FEATURE_UTMP) @@ -183,8 +327,7 @@ auth_failed: alarm(0); die_if_nologin_and_non_root(pw->pw_uid == 0); - if (ENABLE_FEATURE_UTMP) - write_utent(username); + write_utent(username); #ifdef CONFIG_SELINUX if (is_selinux_enabled()) { @@ -255,171 +398,3 @@ auth_failed: return EXIT_FAILURE; } - - -static void get_username_or_die(char *buf, int size_buf) -{ - int c, cntdown; - cntdown = EMPTY_USERNAME_COUNT; -prompt: - /* skip whitespace */ - print_login_prompt(); - do { - c = getchar(); - if (c == EOF) exit(1); - if (c == '\n') { - if (!--cntdown) exit(1); - goto prompt; - } - } while (isspace(c)); - - *buf++ = c; - if (!fgets(buf, size_buf-2, stdin)) - exit(1); - if (!strchr(buf, '\n')) - exit(1); - while (isgraph(*buf)) buf++; - *buf = '\0'; -} - - -static void die_if_nologin_and_non_root(int amroot) -{ - FILE *fp; - int c; - - if (access(bb_path_nologin_file, F_OK)) - return; - - fp = fopen(bb_path_nologin_file, "r"); - if (fp) { - while ((c = getc(fp)) != EOF) - putchar((c=='\n') ? '\r' : c); - fflush(stdout); - fclose(fp); - } else - puts("\r\nSystem closed for routine maintenance\r"); - if (!amroot) - exit(1); - puts("\r\n[Disconnect bypassed -- root login allowed.]\r"); -} - -#if ENABLE_FEATURE_SECURETTY - -static int check_securetty(void) -{ - FILE *fp; - int i; - char buf[BUFSIZ]; - - fp = fopen(bb_path_securetty_file, "r"); - if (!fp) { - /* A missing securetty file is not an error. */ - return 1; - } - while (fgets(buf, sizeof(buf)-1, fp)) { - for(i = strlen(buf)-1; i>=0; --i) { - if (!isspace(buf[i])) - break; - } - buf[++i] = '\0'; - if ((buf[0]=='\0') || (buf[0]=='#')) - continue; - if (strcmp(buf, short_tty) == 0) { - fclose(fp); - return 1; - } - } - fclose(fp); - return 0; -} - -#endif - -static void motd(void) -{ - FILE *fp; - int c; - - fp = fopen(bb_path_motd_file, "r"); - if (fp) { - while ((c = getc(fp)) != EOF) - putchar(c); - fclose(fp); - } -} - - -#if ENABLE_FEATURE_UTMP -/* vv Taken from tinylogin utmp.c vv */ - -/* - * read_or_build_utent - see if utmp file is correct for this process - * - * System V is very picky about the contents of the utmp file - * and requires that a slot for the current process exist. - * The utmp file is scanned for an entry with the same process - * ID. If no entry exists the process exits with a message. - * - * The "picky" flag is for network and other logins that may - * use special flags. It allows the pid checks to be overridden. - * This means that getty should never invoke login with any - * command line flags. - */ - -static void read_or_build_utent(int picky) -{ - struct utmp *ut; - pid_t pid = getpid(); - - setutent(); - - /* First, try to find a valid utmp entry for this process. */ - while ((ut = getutent())) - if (ut->ut_pid == pid && ut->ut_line[0] && ut->ut_id[0] && - (ut->ut_type == LOGIN_PROCESS || ut->ut_type == USER_PROCESS)) - break; - - /* If there is one, just use it, otherwise create a new one. */ - if (ut) { - utent = *ut; - } else { - if (picky) - bb_error_msg_and_die("no utmp entry found"); - - memset(&utent, 0, sizeof(utent)); - utent.ut_type = LOGIN_PROCESS; - utent.ut_pid = pid; - strncpy(utent.ut_line, short_tty, sizeof(utent.ut_line)); - /* This one is only 4 chars wide. Try to fit something - * remotely meaningful by skipping "tty"... */ - strncpy(utent.ut_id, short_tty + 3, sizeof(utent.ut_id)); - strncpy(utent.ut_user, "LOGIN", sizeof(utent.ut_user)); - utent.ut_time = time(NULL); - } -} - -/* - * write_utent - put a USER_PROCESS entry in the utmp file - * - * write_utent changes the type of the current utmp entry to - * USER_PROCESS. the wtmp file will be updated as well. - */ - -static void write_utent(const char *username) -{ - utent.ut_type = USER_PROCESS; - strncpy(utent.ut_user, username, sizeof(utent.ut_user)); - utent.ut_time = time(NULL); - /* other fields already filled in by read_or_build_utent above */ - setutent(); - pututline(&utent); - endutent(); -#if ENABLE_FEATURE_WTMP - if (access(bb_path_wtmp_file, R_OK|W_OK) == -1) { - close(creat(bb_path_wtmp_file, 0664)); - } - updwtmp(bb_path_wtmp_file, &utent); -#endif -} -#endif /* CONFIG_FEATURE_UTMP */ |