[821] | 1 | /* vi: set sw=4 ts=4: */
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| 2 | /*
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| 3 | * Simple telnet server
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| 4 | * Bjorn Wesen, Axis Communications AB (bjornw@axis.com)
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| 5 | *
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| 6 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
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| 7 | *
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| 8 | * ---------------------------------------------------------------------------
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| 9 | * (C) Copyright 2000, Axis Communications AB, LUND, SWEDEN
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| 10 | ****************************************************************************
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| 11 | *
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| 12 | * The telnetd manpage says it all:
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| 13 | *
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| 14 | * Telnetd operates by allocating a pseudo-terminal device (see pty(4)) for
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| 15 | * a client, then creating a login process which has the slave side of the
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| 16 | * pseudo-terminal as stdin, stdout, and stderr. Telnetd manipulates the
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| 17 | * master side of the pseudo-terminal, implementing the telnet protocol and
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| 18 | * passing characters between the remote client and the login process.
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| 19 | *
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| 20 | * Vladimir Oleynik <dzo@simtreas.ru> 2001
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| 21 | * Set process group corrections, initial busybox port
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| 22 | */
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| 23 |
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| 24 | /*#define DEBUG 1 */
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| 25 | #undef DEBUG
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| 26 |
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| 27 | #include <sys/socket.h>
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| 28 | #include <sys/wait.h>
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| 29 | #include <sys/ioctl.h>
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| 30 | #include <string.h>
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| 31 | #include <stdlib.h>
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| 32 | #include <unistd.h>
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| 33 | #include <errno.h>
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| 34 | #include <netinet/in.h>
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| 35 | #include <arpa/inet.h>
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| 36 | #include <fcntl.h>
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| 37 | #include <stdio.h>
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| 38 | #include <signal.h>
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| 39 | #include <termios.h>
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| 40 | #ifdef DEBUG
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| 41 | #define TELCMDS
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| 42 | #define TELOPTS
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| 43 | #endif
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| 44 | #include <arpa/telnet.h>
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| 45 | #include <ctype.h>
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| 46 | #include <sys/syslog.h>
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| 47 |
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| 48 | #include "busybox.h"
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| 49 |
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| 50 | #define BUFSIZE 4000
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| 51 |
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| 52 | #ifdef CONFIG_FEATURE_IPV6
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| 53 | #define SOCKET_TYPE AF_INET6
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| 54 | typedef struct sockaddr_in6 sockaddr_type;
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| 55 | #else
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| 56 | #define SOCKET_TYPE AF_INET
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| 57 | typedef struct sockaddr_in sockaddr_type;
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| 58 | #endif
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| 59 |
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| 60 |
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| 61 | #ifdef CONFIG_LOGIN
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| 62 | static const char *loginpath = "/bin/login";
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| 63 | #else
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| 64 | static const char *loginpath;
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| 65 | #endif
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| 66 | static const char *issuefile = "/etc/issue.net";
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| 67 |
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| 68 | /* shell name and arguments */
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| 69 |
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| 70 | static const char *argv_init[] = {NULL, NULL};
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| 71 |
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| 72 | /* structure that describes a session */
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| 73 |
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| 74 | struct tsession {
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| 75 | #ifdef CONFIG_FEATURE_TELNETD_INETD
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| 76 | int sockfd_read, sockfd_write, ptyfd;
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| 77 | #else /* CONFIG_FEATURE_TELNETD_INETD */
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| 78 | struct tsession *next;
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| 79 | int sockfd, ptyfd;
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| 80 | #endif /* CONFIG_FEATURE_TELNETD_INETD */
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| 81 | int shell_pid;
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| 82 | /* two circular buffers */
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| 83 | char *buf1, *buf2;
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| 84 | int rdidx1, wridx1, size1;
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| 85 | int rdidx2, wridx2, size2;
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| 86 | };
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| 87 |
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| 88 | /*
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| 89 |
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| 90 | This is how the buffers are used. The arrows indicate the movement
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| 91 | of data.
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| 92 |
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| 93 | +-------+ wridx1++ +------+ rdidx1++ +----------+
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| 94 | | | <-------------- | buf1 | <-------------- | |
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| 95 | | | size1-- +------+ size1++ | |
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| 96 | | pty | | socket |
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| 97 | | | rdidx2++ +------+ wridx2++ | |
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| 98 | | | --------------> | buf2 | --------------> | |
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| 99 | +-------+ size2++ +------+ size2-- +----------+
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| 100 |
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| 101 | Each session has got two buffers.
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| 102 |
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| 103 | */
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| 104 |
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| 105 | static int maxfd;
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| 106 |
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| 107 | static struct tsession *sessions;
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| 108 |
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| 109 |
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| 110 | /*
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| 111 |
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| 112 | Remove all IAC's from the buffer pointed to by bf (received IACs are ignored
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| 113 | and must be removed so as to not be interpreted by the terminal). Make an
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| 114 | uninterrupted string of characters fit for the terminal. Do this by packing
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| 115 | all characters meant for the terminal sequentially towards the end of bf.
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| 116 |
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| 117 | Return a pointer to the beginning of the characters meant for the terminal.
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| 118 | and make *num_totty the number of characters that should be sent to
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| 119 | the terminal.
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| 120 |
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| 121 | Note - If an IAC (3 byte quantity) starts before (bf + len) but extends
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| 122 | past (bf + len) then that IAC will be left unprocessed and *processed will be
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| 123 | less than len.
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| 124 |
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| 125 | FIXME - if we mean to send 0xFF to the terminal then it will be escaped,
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| 126 | what is the escape character? We aren't handling that situation here.
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| 127 |
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| 128 | CR-LF ->'s CR mapping is also done here, for convenience
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| 129 |
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| 130 | */
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| 131 | static char *
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| 132 | remove_iacs(struct tsession *ts, int *pnum_totty) {
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| 133 | unsigned char *ptr0 = (unsigned char *)ts->buf1 + ts->wridx1;
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| 134 | unsigned char *ptr = ptr0;
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| 135 | unsigned char *totty = ptr;
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| 136 | unsigned char *end = ptr + MIN(BUFSIZE - ts->wridx1, ts->size1);
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| 137 | int processed;
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| 138 | int num_totty;
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| 139 |
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| 140 | while (ptr < end) {
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| 141 | if (*ptr != IAC) {
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| 142 | int c = *ptr;
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| 143 | *totty++ = *ptr++;
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| 144 | /* We now map \r\n ==> \r for pragmatic reasons.
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| 145 | * Many client implementations send \r\n when
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| 146 | * the user hits the CarriageReturn key.
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| 147 | */
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| 148 | if (c == '\r' && (*ptr == '\n' || *ptr == 0) && ptr < end)
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| 149 | ptr++;
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| 150 | }
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| 151 | else {
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| 152 | /*
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| 153 | * TELOPT_NAWS support!
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| 154 | */
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| 155 | if ((ptr+2) >= end) {
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| 156 | /* only the beginning of the IAC is in the
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| 157 | buffer we were asked to process, we can't
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| 158 | process this char. */
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| 159 | break;
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| 160 | }
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| 161 |
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| 162 | /*
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| 163 | * IAC -> SB -> TELOPT_NAWS -> 4-byte -> IAC -> SE
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| 164 | */
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| 165 | else if (ptr[1] == SB && ptr[2] == TELOPT_NAWS) {
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| 166 | struct winsize ws;
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| 167 | if ((ptr+8) >= end)
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| 168 | break; /* incomplete, can't process */
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| 169 | ws.ws_col = (ptr[3] << 8) | ptr[4];
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| 170 | ws.ws_row = (ptr[5] << 8) | ptr[6];
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| 171 | (void) ioctl(ts->ptyfd, TIOCSWINSZ, (char *)&ws);
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| 172 | ptr += 9;
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| 173 | }
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| 174 | else {
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| 175 | /* skip 3-byte IAC non-SB cmd */
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| 176 | #ifdef DEBUG
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| 177 | fprintf(stderr, "Ignoring IAC %s,%s\n",
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| 178 | TELCMD(*(ptr+1)), TELOPT(*(ptr+2)));
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| 179 | #endif
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| 180 | ptr += 3;
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| 181 | }
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| 182 | }
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| 183 | }
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| 184 |
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| 185 | processed = ptr - ptr0;
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| 186 | num_totty = totty - ptr0;
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| 187 | /* the difference between processed and num_to tty
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| 188 | is all the iacs we removed from the stream.
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| 189 | Adjust buf1 accordingly. */
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| 190 | ts->wridx1 += processed - num_totty;
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| 191 | ts->size1 -= processed - num_totty;
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| 192 | *pnum_totty = num_totty;
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| 193 | /* move the chars meant for the terminal towards the end of the
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| 194 | buffer. */
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| 195 | return memmove(ptr - num_totty, ptr0, num_totty);
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| 196 | }
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| 197 |
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| 198 |
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| 199 | static int
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| 200 | getpty(char *line)
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| 201 | {
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| 202 | int p;
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| 203 | #ifdef CONFIG_FEATURE_DEVPTS
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| 204 | p = open("/dev/ptmx", 2);
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| 205 | if (p > 0) {
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| 206 | grantpt(p);
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| 207 | unlockpt(p);
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| 208 | strcpy(line, ptsname(p));
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| 209 | return(p);
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| 210 | }
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| 211 | #else
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| 212 | struct stat stb;
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| 213 | int i;
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| 214 | int j;
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| 215 |
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| 216 | strcpy(line, "/dev/ptyXX");
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| 217 |
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| 218 | for (i = 0; i < 16; i++) {
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| 219 | line[8] = "pqrstuvwxyzabcde"[i];
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| 220 | line[9] = '0';
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| 221 | if (stat(line, &stb) < 0) {
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| 222 | continue;
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| 223 | }
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| 224 | for (j = 0; j < 16; j++) {
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| 225 | line[9] = j < 10 ? j + '0' : j - 10 + 'a';
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| 226 | #ifdef DEBUG
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| 227 | fprintf(stderr, "Trying to open device: %s\n", line);
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| 228 | #endif
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| 229 | if ((p = open(line, O_RDWR | O_NOCTTY)) >= 0) {
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| 230 | line[5] = 't';
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| 231 | return p;
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| 232 | }
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| 233 | }
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| 234 | }
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| 235 | #endif /* CONFIG_FEATURE_DEVPTS */
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| 236 | return -1;
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| 237 | }
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| 238 |
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| 239 |
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| 240 | static void
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| 241 | send_iac(struct tsession *ts, unsigned char command, int option)
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| 242 | {
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| 243 | /* We rely on that there is space in the buffer for now. */
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| 244 | char *b = ts->buf2 + ts->rdidx2;
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| 245 | *b++ = IAC;
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| 246 | *b++ = command;
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| 247 | *b++ = option;
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| 248 | ts->rdidx2 += 3;
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| 249 | ts->size2 += 3;
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| 250 | }
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| 251 |
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| 252 |
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| 253 | static struct tsession *
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| 254 | #ifdef CONFIG_FEATURE_TELNETD_INETD
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| 255 | make_new_session(void)
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| 256 | #else /* CONFIG_FEATURE_TELNETD_INETD */
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| 257 | make_new_session(int sockfd)
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| 258 | #endif /* CONFIG_FEATURE_TELNETD_INETD */
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| 259 | {
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| 260 | struct termios termbuf;
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| 261 | int pty, pid;
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| 262 | char tty_name[32];
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| 263 | struct tsession *ts = xzalloc(sizeof(struct tsession) + BUFSIZE * 2);
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| 264 |
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| 265 | ts->buf1 = (char *)(&ts[1]);
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| 266 | ts->buf2 = ts->buf1 + BUFSIZE;
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| 267 |
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| 268 | #ifdef CONFIG_FEATURE_TELNETD_INETD
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| 269 | ts->sockfd_write = 1;
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| 270 | #else /* CONFIG_FEATURE_TELNETD_INETD */
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| 271 | ts->sockfd = sockfd;
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| 272 | #endif /* CONFIG_FEATURE_TELNETD_INETD */
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| 273 |
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| 274 | /* Got a new connection, set up a tty and spawn a shell. */
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| 275 |
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| 276 | pty = getpty(tty_name);
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| 277 |
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| 278 | if (pty < 0) {
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| 279 | syslog(LOG_ERR, "All terminals in use!");
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| 280 | return 0;
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| 281 | }
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| 282 |
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| 283 | if (pty > maxfd)
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| 284 | maxfd = pty;
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| 285 |
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| 286 | ts->ptyfd = pty;
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| 287 |
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| 288 | /* Make the telnet client understand we will echo characters so it
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| 289 | * should not do it locally. We don't tell the client to run linemode,
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| 290 | * because we want to handle line editing and tab completion and other
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| 291 | * stuff that requires char-by-char support.
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| 292 | */
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| 293 |
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| 294 | send_iac(ts, DO, TELOPT_ECHO);
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| 295 | send_iac(ts, DO, TELOPT_NAWS);
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| 296 | send_iac(ts, DO, TELOPT_LFLOW);
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| 297 | send_iac(ts, WILL, TELOPT_ECHO);
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| 298 | send_iac(ts, WILL, TELOPT_SGA);
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| 299 |
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| 300 | if ((pid = fork()) < 0) {
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| 301 | syslog(LOG_ERR, "Could not fork");
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| 302 | }
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| 303 | if (pid == 0) {
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| 304 | /* In child, open the child's side of the tty. */
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| 305 | int i;
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| 306 |
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| 307 | for(i = 0; i <= maxfd; i++)
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| 308 | close(i);
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| 309 | /* make new process group */
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| 310 | setsid();
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| 311 |
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| 312 | if (open(tty_name, O_RDWR /*| O_NOCTTY*/) < 0) {
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| 313 | syslog(LOG_ERR, "Could not open tty");
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| 314 | exit(1);
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| 315 | }
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| 316 | dup(0);
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| 317 | dup(0);
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| 318 |
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| 319 | tcsetpgrp(0, getpid());
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| 320 |
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| 321 | /* The pseudo-terminal allocated to the client is configured to operate in
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| 322 | * cooked mode, and with XTABS CRMOD enabled (see tty(4)).
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| 323 | */
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| 324 |
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| 325 | tcgetattr(0, &termbuf);
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| 326 | termbuf.c_lflag |= ECHO; /* if we use readline we dont want this */
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| 327 | termbuf.c_oflag |= ONLCR|XTABS;
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| 328 | termbuf.c_iflag |= ICRNL;
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| 329 | termbuf.c_iflag &= ~IXOFF;
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| 330 | /*termbuf.c_lflag &= ~ICANON;*/
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| 331 | tcsetattr(0, TCSANOW, &termbuf);
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| 332 |
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| 333 | print_login_issue(issuefile, NULL);
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| 334 |
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| 335 | /* exec shell, with correct argv and env */
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| 336 | execv(loginpath, (char *const *)argv_init);
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| 337 |
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| 338 | /* NOT REACHED */
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| 339 | syslog(LOG_ERR, "execv error");
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| 340 | exit(1);
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| 341 | }
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| 342 |
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| 343 | ts->shell_pid = pid;
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| 344 |
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| 345 | return ts;
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| 346 | }
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| 347 |
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| 348 | #ifndef CONFIG_FEATURE_TELNETD_INETD
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| 349 | static void
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| 350 | free_session(struct tsession *ts)
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| 351 | {
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| 352 | struct tsession *t = sessions;
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| 353 |
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| 354 | /* Unlink this telnet session from the session list. */
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| 355 | if (t == ts)
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| 356 | sessions = ts->next;
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| 357 | else {
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| 358 | while(t->next != ts)
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| 359 | t = t->next;
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| 360 | t->next = ts->next;
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| 361 | }
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| 362 |
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| 363 | kill(ts->shell_pid, SIGKILL);
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| 364 |
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| 365 | wait4(ts->shell_pid, NULL, 0, NULL);
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| 366 |
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| 367 | close(ts->ptyfd);
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| 368 | close(ts->sockfd);
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| 369 |
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| 370 | if (ts->ptyfd == maxfd || ts->sockfd == maxfd)
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| 371 | maxfd--;
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| 372 | if (ts->ptyfd == maxfd || ts->sockfd == maxfd)
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| 373 | maxfd--;
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| 374 |
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| 375 | free(ts);
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| 376 | }
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| 377 | #endif /* CONFIG_FEATURE_TELNETD_INETD */
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| 378 |
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| 379 | int
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| 380 | telnetd_main(int argc, char **argv)
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| 381 | {
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| 382 | #ifndef CONFIG_FEATURE_TELNETD_INETD
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| 383 | sockaddr_type sa;
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| 384 | int master_fd;
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| 385 | #endif /* CONFIG_FEATURE_TELNETD_INETD */
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| 386 | fd_set rdfdset, wrfdset;
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| 387 | int selret;
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| 388 | #ifndef CONFIG_FEATURE_TELNETD_INETD
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| 389 | int on = 1;
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| 390 | int portnbr = 23;
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| 391 | struct in_addr bind_addr = { .s_addr = 0x0 };
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| 392 | #endif /* CONFIG_FEATURE_TELNETD_INETD */
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| 393 | int c;
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| 394 | static const char options[] =
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| 395 | #ifdef CONFIG_FEATURE_TELNETD_INETD
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| 396 | "f:l:";
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| 397 | #else /* CONFIG_EATURE_TELNETD_INETD */
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| 398 | "f:l:p:b:";
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| 399 | #endif /* CONFIG_FEATURE_TELNETD_INETD */
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| 400 | int maxlen, w, r;
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| 401 |
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| 402 | #ifndef CONFIG_LOGIN
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| 403 | loginpath = DEFAULT_SHELL;
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| 404 | #endif
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| 405 |
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| 406 | for (;;) {
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| 407 | c = getopt( argc, argv, options);
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| 408 | if (c == EOF) break;
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| 409 | switch (c) {
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| 410 | case 'f':
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| 411 | issuefile = optarg;
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| 412 | break;
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| 413 | case 'l':
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| 414 | loginpath = optarg;
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| 415 | break;
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| 416 | #ifndef CONFIG_FEATURE_TELNETD_INETD
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| 417 | case 'p':
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| 418 | portnbr = atoi(optarg);
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| 419 | break;
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| 420 | case 'b':
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| 421 | if (inet_aton(optarg, &bind_addr) == 0)
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| 422 | bb_show_usage();
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| 423 | break;
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| 424 | #endif /* CONFIG_FEATURE_TELNETD_INETD */
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| 425 | default:
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| 426 | bb_show_usage();
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| 427 | }
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| 428 | }
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| 429 |
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| 430 | if (access(loginpath, X_OK) < 0) {
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| 431 | bb_error_msg_and_die ("'%s' unavailable.", loginpath);
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| 432 | }
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| 433 |
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| 434 | argv_init[0] = loginpath;
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| 435 |
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| 436 | openlog(bb_applet_name, 0, LOG_USER);
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| 437 |
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| 438 | #ifdef CONFIG_FEATURE_TELNETD_INETD
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| 439 | maxfd = 1;
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| 440 | sessions = make_new_session();
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| 441 | #else /* CONFIG_EATURE_TELNETD_INETD */
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| 442 | sessions = 0;
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| 443 |
|
---|
| 444 | /* Grab a TCP socket. */
|
---|
| 445 |
|
---|
| 446 | master_fd = bb_xsocket(SOCKET_TYPE, SOCK_STREAM, 0);
|
---|
| 447 | (void)setsockopt(master_fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
|
---|
| 448 |
|
---|
| 449 | /* Set it to listen to specified port. */
|
---|
| 450 |
|
---|
| 451 | memset((void *)&sa, 0, sizeof(sa));
|
---|
| 452 | #ifdef CONFIG_FEATURE_IPV6
|
---|
| 453 | sa.sin6_family = AF_INET6;
|
---|
| 454 | sa.sin6_port = htons(portnbr);
|
---|
| 455 | /* sa.sin6_addr = bind_addr6; */
|
---|
| 456 | #else
|
---|
| 457 | sa.sin_family = AF_INET;
|
---|
| 458 | sa.sin_port = htons(portnbr);
|
---|
| 459 | sa.sin_addr = bind_addr;
|
---|
| 460 | #endif
|
---|
| 461 |
|
---|
| 462 | bb_xbind(master_fd, (struct sockaddr *) &sa, sizeof(sa));
|
---|
| 463 | bb_xlisten(master_fd, 1);
|
---|
| 464 | bb_xdaemon(0, 0);
|
---|
| 465 |
|
---|
| 466 | maxfd = master_fd;
|
---|
| 467 | #endif /* CONFIG_FEATURE_TELNETD_INETD */
|
---|
| 468 |
|
---|
| 469 | do {
|
---|
| 470 | struct tsession *ts;
|
---|
| 471 |
|
---|
| 472 | FD_ZERO(&rdfdset);
|
---|
| 473 | FD_ZERO(&wrfdset);
|
---|
| 474 |
|
---|
| 475 | /* select on the master socket, all telnet sockets and their
|
---|
| 476 | * ptys if there is room in their respective session buffers.
|
---|
| 477 | */
|
---|
| 478 |
|
---|
| 479 | #ifndef CONFIG_FEATURE_TELNETD_INETD
|
---|
| 480 | FD_SET(master_fd, &rdfdset);
|
---|
| 481 | #endif /* CONFIG_FEATURE_TELNETD_INETD */
|
---|
| 482 |
|
---|
| 483 | ts = sessions;
|
---|
| 484 | #ifndef CONFIG_FEATURE_TELNETD_INETD
|
---|
| 485 | while (ts) {
|
---|
| 486 | #endif /* CONFIG_FEATURE_TELNETD_INETD */
|
---|
| 487 | /* buf1 is used from socket to pty
|
---|
| 488 | * buf2 is used from pty to socket
|
---|
| 489 | */
|
---|
| 490 | if (ts->size1 > 0) {
|
---|
| 491 | FD_SET(ts->ptyfd, &wrfdset); /* can write to pty */
|
---|
| 492 | }
|
---|
| 493 | if (ts->size1 < BUFSIZE) {
|
---|
| 494 | #ifdef CONFIG_FEATURE_TELNETD_INETD
|
---|
| 495 | FD_SET(ts->sockfd_read, &rdfdset); /* can read from socket */
|
---|
| 496 | #else /* CONFIG_FEATURE_TELNETD_INETD */
|
---|
| 497 | FD_SET(ts->sockfd, &rdfdset); /* can read from socket */
|
---|
| 498 | #endif /* CONFIG_FEATURE_TELNETD_INETD */
|
---|
| 499 | }
|
---|
| 500 | if (ts->size2 > 0) {
|
---|
| 501 | #ifdef CONFIG_FEATURE_TELNETD_INETD
|
---|
| 502 | FD_SET(ts->sockfd_write, &wrfdset); /* can write to socket */
|
---|
| 503 | #else /* CONFIG_FEATURE_TELNETD_INETD */
|
---|
| 504 | FD_SET(ts->sockfd, &wrfdset); /* can write to socket */
|
---|
| 505 | #endif /* CONFIG_FEATURE_TELNETD_INETD */
|
---|
| 506 | }
|
---|
| 507 | if (ts->size2 < BUFSIZE) {
|
---|
| 508 | FD_SET(ts->ptyfd, &rdfdset); /* can read from pty */
|
---|
| 509 | }
|
---|
| 510 | #ifndef CONFIG_FEATURE_TELNETD_INETD
|
---|
| 511 | ts = ts->next;
|
---|
| 512 | }
|
---|
| 513 | #endif /* CONFIG_FEATURE_TELNETD_INETD */
|
---|
| 514 |
|
---|
| 515 | selret = select(maxfd + 1, &rdfdset, &wrfdset, 0, 0);
|
---|
| 516 |
|
---|
| 517 | if (!selret)
|
---|
| 518 | break;
|
---|
| 519 |
|
---|
| 520 | #ifndef CONFIG_FEATURE_TELNETD_INETD
|
---|
| 521 | /* First check for and accept new sessions. */
|
---|
| 522 | if (FD_ISSET(master_fd, &rdfdset)) {
|
---|
| 523 | int fd;
|
---|
| 524 | socklen_t salen;
|
---|
| 525 |
|
---|
| 526 | salen = sizeof(sa);
|
---|
| 527 | if ((fd = accept(master_fd, (struct sockaddr *)&sa,
|
---|
| 528 | &salen)) < 0) {
|
---|
| 529 | continue;
|
---|
| 530 | } else {
|
---|
| 531 | /* Create a new session and link it into
|
---|
| 532 | our active list. */
|
---|
| 533 | struct tsession *new_ts = make_new_session(fd);
|
---|
| 534 | if (new_ts) {
|
---|
| 535 | new_ts->next = sessions;
|
---|
| 536 | sessions = new_ts;
|
---|
| 537 | if (fd > maxfd)
|
---|
| 538 | maxfd = fd;
|
---|
| 539 | } else {
|
---|
| 540 | close(fd);
|
---|
| 541 | }
|
---|
| 542 | }
|
---|
| 543 | }
|
---|
| 544 |
|
---|
| 545 | /* Then check for data tunneling. */
|
---|
| 546 |
|
---|
| 547 | ts = sessions;
|
---|
| 548 | while (ts) { /* For all sessions... */
|
---|
| 549 | #endif /* CONFIG_FEATURE_TELNETD_INETD */
|
---|
| 550 | #ifndef CONFIG_FEATURE_TELNETD_INETD
|
---|
| 551 | struct tsession *next = ts->next; /* in case we free ts. */
|
---|
| 552 | #endif /* CONFIG_FEATURE_TELNETD_INETD */
|
---|
| 553 |
|
---|
| 554 | if (ts->size1 && FD_ISSET(ts->ptyfd, &wrfdset)) {
|
---|
| 555 | int num_totty;
|
---|
| 556 | char *ptr;
|
---|
| 557 | /* Write to pty from buffer 1. */
|
---|
| 558 |
|
---|
| 559 | ptr = remove_iacs(ts, &num_totty);
|
---|
| 560 |
|
---|
| 561 | w = write(ts->ptyfd, ptr, num_totty);
|
---|
| 562 | if (w < 0) {
|
---|
| 563 | #ifdef CONFIG_FEATURE_TELNETD_INETD
|
---|
| 564 | exit(0);
|
---|
| 565 | #else /* CONFIG_FEATURE_TELNETD_INETD */
|
---|
| 566 | free_session(ts);
|
---|
| 567 | ts = next;
|
---|
| 568 | continue;
|
---|
| 569 | #endif /* CONFIG_FEATURE_TELNETD_INETD */
|
---|
| 570 | }
|
---|
| 571 | ts->wridx1 += w;
|
---|
| 572 | ts->size1 -= w;
|
---|
| 573 | if (ts->wridx1 == BUFSIZE)
|
---|
| 574 | ts->wridx1 = 0;
|
---|
| 575 | }
|
---|
| 576 |
|
---|
| 577 | #ifdef CONFIG_FEATURE_TELNETD_INETD
|
---|
| 578 | if (ts->size2 && FD_ISSET(ts->sockfd_write, &wrfdset)) {
|
---|
| 579 | #else /* CONFIG_FEATURE_TELNETD_INETD */
|
---|
| 580 | if (ts->size2 && FD_ISSET(ts->sockfd, &wrfdset)) {
|
---|
| 581 | #endif /* CONFIG_FEATURE_TELNETD_INETD */
|
---|
| 582 | /* Write to socket from buffer 2. */
|
---|
| 583 | maxlen = MIN(BUFSIZE - ts->wridx2, ts->size2);
|
---|
| 584 | #ifdef CONFIG_FEATURE_TELNETD_INETD
|
---|
| 585 | w = write(ts->sockfd_write, ts->buf2 + ts->wridx2, maxlen);
|
---|
| 586 | if (w < 0)
|
---|
| 587 | exit(0);
|
---|
| 588 | #else /* CONFIG_FEATURE_TELNETD_INETD */
|
---|
| 589 | w = write(ts->sockfd, ts->buf2 + ts->wridx2, maxlen);
|
---|
| 590 | if (w < 0) {
|
---|
| 591 | free_session(ts);
|
---|
| 592 | ts = next;
|
---|
| 593 | continue;
|
---|
| 594 | }
|
---|
| 595 | #endif /* CONFIG_FEATURE_TELNETD_INETD */
|
---|
| 596 | ts->wridx2 += w;
|
---|
| 597 | ts->size2 -= w;
|
---|
| 598 | if (ts->wridx2 == BUFSIZE)
|
---|
| 599 | ts->wridx2 = 0;
|
---|
| 600 | }
|
---|
| 601 |
|
---|
| 602 | #ifdef CONFIG_FEATURE_TELNETD_INETD
|
---|
| 603 | if (ts->size1 < BUFSIZE && FD_ISSET(ts->sockfd_read, &rdfdset)) {
|
---|
| 604 | #else /* CONFIG_FEATURE_TELNETD_INETD */
|
---|
| 605 | if (ts->size1 < BUFSIZE && FD_ISSET(ts->sockfd, &rdfdset)) {
|
---|
| 606 | #endif /* CONFIG_FEATURE_TELNETD_INETD */
|
---|
| 607 | /* Read from socket to buffer 1. */
|
---|
| 608 | maxlen = MIN(BUFSIZE - ts->rdidx1,
|
---|
| 609 | BUFSIZE - ts->size1);
|
---|
| 610 | #ifdef CONFIG_FEATURE_TELNETD_INETD
|
---|
| 611 | r = read(ts->sockfd_read, ts->buf1 + ts->rdidx1, maxlen);
|
---|
| 612 | if (!r || (r < 0 && errno != EINTR))
|
---|
| 613 | exit(0);
|
---|
| 614 | #else /* CONFIG_FEATURE_TELNETD_INETD */
|
---|
| 615 | r = read(ts->sockfd, ts->buf1 + ts->rdidx1, maxlen);
|
---|
| 616 | if (!r || (r < 0 && errno != EINTR)) {
|
---|
| 617 | free_session(ts);
|
---|
| 618 | ts = next;
|
---|
| 619 | continue;
|
---|
| 620 | }
|
---|
| 621 | #endif /* CONFIG_FEATURE_TELNETD_INETD */
|
---|
| 622 | if (!*(ts->buf1 + ts->rdidx1 + r - 1)) {
|
---|
| 623 | r--;
|
---|
| 624 | if (!r)
|
---|
| 625 | continue;
|
---|
| 626 | }
|
---|
| 627 | ts->rdidx1 += r;
|
---|
| 628 | ts->size1 += r;
|
---|
| 629 | if (ts->rdidx1 == BUFSIZE)
|
---|
| 630 | ts->rdidx1 = 0;
|
---|
| 631 | }
|
---|
| 632 |
|
---|
| 633 | if (ts->size2 < BUFSIZE && FD_ISSET(ts->ptyfd, &rdfdset)) {
|
---|
| 634 | /* Read from pty to buffer 2. */
|
---|
| 635 | maxlen = MIN(BUFSIZE - ts->rdidx2,
|
---|
| 636 | BUFSIZE - ts->size2);
|
---|
| 637 | r = read(ts->ptyfd, ts->buf2 + ts->rdidx2, maxlen);
|
---|
| 638 | if (!r || (r < 0 && errno != EINTR)) {
|
---|
| 639 | #ifdef CONFIG_FEATURE_TELNETD_INETD
|
---|
| 640 | exit(0);
|
---|
| 641 | #else /* CONFIG_FEATURE_TELNETD_INETD */
|
---|
| 642 | free_session(ts);
|
---|
| 643 | ts = next;
|
---|
| 644 | continue;
|
---|
| 645 | #endif /* CONFIG_FEATURE_TELNETD_INETD */
|
---|
| 646 | }
|
---|
| 647 | ts->rdidx2 += r;
|
---|
| 648 | ts->size2 += r;
|
---|
| 649 | if (ts->rdidx2 == BUFSIZE)
|
---|
| 650 | ts->rdidx2 = 0;
|
---|
| 651 | }
|
---|
| 652 |
|
---|
| 653 | if (ts->size1 == 0) {
|
---|
| 654 | ts->rdidx1 = 0;
|
---|
| 655 | ts->wridx1 = 0;
|
---|
| 656 | }
|
---|
| 657 | if (ts->size2 == 0) {
|
---|
| 658 | ts->rdidx2 = 0;
|
---|
| 659 | ts->wridx2 = 0;
|
---|
| 660 | }
|
---|
| 661 | #ifndef CONFIG_FEATURE_TELNETD_INETD
|
---|
| 662 | ts = next;
|
---|
| 663 | }
|
---|
| 664 | #endif /* CONFIG_FEATURE_TELNETD_INETD */
|
---|
| 665 |
|
---|
| 666 | } while (1);
|
---|
| 667 |
|
---|
| 668 | return 0;
|
---|
| 669 | }
|
---|