[3320] | 1 | /* vi: set sw=4 ts=4: */
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| 2 | /*
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| 3 | * A simple tftp client/server for busybox.
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| 4 | * Tries to follow RFC1350.
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| 5 | * Only "octet" mode supported.
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| 6 | * Optional blocksize negotiation (RFC2347 + RFC2348)
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| 7 | *
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| 8 | * Copyright (C) 2001 Magnus Damm <damm@opensource.se>
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| 9 | *
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| 10 | * Parts of the code based on:
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| 11 | *
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| 12 | * atftp: Copyright (C) 2000 Jean-Pierre Lefebvre <helix@step.polymtl.ca>
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| 13 | * and Remi Lefebvre <remi@debian.org>
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| 14 | *
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| 15 | * utftp: Copyright (C) 1999 Uwe Ohse <uwe@ohse.de>
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| 16 | *
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| 17 | * tftpd added by Denys Vlasenko & Vladimir Dronnikov
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| 18 | *
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| 19 | * Licensed under GPLv2 or later, see file LICENSE in this source tree.
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| 20 | */
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| 21 | #include "libbb.h"
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| 22 |
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| 23 | #if ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT
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| 24 |
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| 25 | #define TFTP_BLKSIZE_DEFAULT 512 /* according to RFC 1350, don't change */
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| 26 | #define TFTP_BLKSIZE_DEFAULT_STR "512"
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| 27 | /* Was 50 ms but users asked to bump it up a bit */
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| 28 | #define TFTP_TIMEOUT_MS 100
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| 29 | #define TFTP_MAXTIMEOUT_MS 2000
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| 30 | #define TFTP_NUM_RETRIES 12 /* number of backed-off retries */
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| 31 |
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| 32 | /* opcodes we support */
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| 33 | #define TFTP_RRQ 1
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| 34 | #define TFTP_WRQ 2
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| 35 | #define TFTP_DATA 3
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| 36 | #define TFTP_ACK 4
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| 37 | #define TFTP_ERROR 5
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| 38 | #define TFTP_OACK 6
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| 39 |
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| 40 | /* error codes sent over network (we use only 0, 1, 3 and 8) */
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| 41 | /* generic (error message is included in the packet) */
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| 42 | #define ERR_UNSPEC 0
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| 43 | #define ERR_NOFILE 1
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| 44 | #define ERR_ACCESS 2
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| 45 | /* disk full or allocation exceeded */
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| 46 | #define ERR_WRITE 3
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| 47 | #define ERR_OP 4
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| 48 | #define ERR_BAD_ID 5
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| 49 | #define ERR_EXIST 6
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| 50 | #define ERR_BAD_USER 7
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| 51 | #define ERR_BAD_OPT 8
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| 52 |
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| 53 | /* masks coming from getopt32 */
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| 54 | enum {
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| 55 | TFTP_OPT_GET = (1 << 0),
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| 56 | TFTP_OPT_PUT = (1 << 1),
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| 57 | /* pseudo option: if set, it's tftpd */
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| 58 | TFTPD_OPT = (1 << 7) * ENABLE_TFTPD,
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| 59 | TFTPD_OPT_r = (1 << 8) * ENABLE_TFTPD,
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| 60 | TFTPD_OPT_c = (1 << 9) * ENABLE_TFTPD,
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| 61 | TFTPD_OPT_u = (1 << 10) * ENABLE_TFTPD,
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| 62 | };
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| 63 |
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| 64 | #if ENABLE_FEATURE_TFTP_GET && !ENABLE_FEATURE_TFTP_PUT
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| 65 | #define IF_GETPUT(...)
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| 66 | #define CMD_GET(cmd) 1
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| 67 | #define CMD_PUT(cmd) 0
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| 68 | #elif !ENABLE_FEATURE_TFTP_GET && ENABLE_FEATURE_TFTP_PUT
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| 69 | #define IF_GETPUT(...)
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| 70 | #define CMD_GET(cmd) 0
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| 71 | #define CMD_PUT(cmd) 1
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| 72 | #else
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| 73 | #define IF_GETPUT(...) __VA_ARGS__
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| 74 | #define CMD_GET(cmd) ((cmd) & TFTP_OPT_GET)
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| 75 | #define CMD_PUT(cmd) ((cmd) & TFTP_OPT_PUT)
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| 76 | #endif
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| 77 | /* NB: in the code below
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| 78 | * CMD_GET(cmd) and CMD_PUT(cmd) are mutually exclusive
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| 79 | */
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| 80 |
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| 81 |
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| 82 | struct globals {
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| 83 | /* u16 TFTP_ERROR; u16 reason; both network-endian, then error text: */
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| 84 | uint8_t error_pkt[4 + 32];
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| 85 | char *user_opt;
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| 86 | /* used in tftpd_main(), a bit big for stack: */
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| 87 | char block_buf[TFTP_BLKSIZE_DEFAULT];
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| 88 | #if ENABLE_FEATURE_TFTP_PROGRESS_BAR
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| 89 | off_t pos;
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| 90 | off_t size;
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| 91 | const char *file;
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| 92 | bb_progress_t pmt;
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| 93 | #endif
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| 94 | } FIX_ALIASING;
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| 95 | #define G (*(struct globals*)&bb_common_bufsiz1)
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| 96 | struct BUG_G_too_big {
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| 97 | char BUG_G_too_big[sizeof(G) <= COMMON_BUFSIZE ? 1 : -1];
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| 98 | };
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| 99 | #define block_buf (G.block_buf )
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| 100 | #define user_opt (G.user_opt )
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| 101 | #define error_pkt (G.error_pkt )
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| 102 | #define INIT_G() do { } while (0)
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| 103 |
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| 104 | #define error_pkt_reason (error_pkt[3])
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| 105 | #define error_pkt_str (error_pkt + 4)
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| 106 |
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| 107 | #if ENABLE_FEATURE_TFTP_PROGRESS_BAR
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| 108 | static void tftp_progress_update(void)
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| 109 | {
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| 110 | bb_progress_update(&G.pmt, G.file, 0, G.pos, G.size);
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| 111 | }
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| 112 | static void tftp_progress_init(void)
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| 113 | {
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| 114 | bb_progress_init(&G.pmt);
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| 115 | tftp_progress_update();
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| 116 | }
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| 117 | static void tftp_progress_done(void)
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| 118 | {
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| 119 | if (G.pmt.inited) {
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| 120 | tftp_progress_update();
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| 121 | bb_putchar_stderr('\n');
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| 122 | G.pmt.inited = 0;
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| 123 | }
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| 124 | }
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| 125 | #else
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| 126 | # define tftp_progress_init() ((void)0)
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| 127 | # define tftp_progress_done() ((void)0)
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| 128 | #endif
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| 129 |
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| 130 | #if ENABLE_FEATURE_TFTP_BLOCKSIZE
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| 131 |
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| 132 | static int tftp_blksize_check(const char *blksize_str, int maxsize)
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| 133 | {
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| 134 | /* Check if the blksize is valid:
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| 135 | * RFC2348 says between 8 and 65464,
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| 136 | * but our implementation makes it impossible
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| 137 | * to use blksizes smaller than 22 octets. */
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| 138 | unsigned blksize = bb_strtou(blksize_str, NULL, 10);
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| 139 | if (errno
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| 140 | || (blksize < 24) || (blksize > maxsize)
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| 141 | ) {
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| 142 | bb_error_msg("bad blocksize '%s'", blksize_str);
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| 143 | return -1;
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| 144 | }
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| 145 | # if ENABLE_TFTP_DEBUG
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| 146 | bb_error_msg("using blksize %u", blksize);
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| 147 | # endif
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| 148 | return blksize;
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| 149 | }
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| 150 |
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| 151 | static char *tftp_get_option(const char *option, char *buf, int len)
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| 152 | {
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| 153 | int opt_val = 0;
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| 154 | int opt_found = 0;
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| 155 | int k;
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| 156 |
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| 157 | /* buf points to:
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| 158 | * "opt_name<NUL>opt_val<NUL>opt_name2<NUL>opt_val2<NUL>..." */
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| 159 |
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| 160 | while (len > 0) {
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| 161 | /* Make sure options are terminated correctly */
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| 162 | for (k = 0; k < len; k++) {
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| 163 | if (buf[k] == '\0') {
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| 164 | goto nul_found;
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| 165 | }
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| 166 | }
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| 167 | return NULL;
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| 168 | nul_found:
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| 169 | if (opt_val == 0) { /* it's "name" part */
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| 170 | if (strcasecmp(buf, option) == 0) {
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| 171 | opt_found = 1;
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| 172 | }
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| 173 | } else if (opt_found) {
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| 174 | return buf;
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| 175 | }
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| 176 |
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| 177 | k++;
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| 178 | buf += k;
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| 179 | len -= k;
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| 180 | opt_val ^= 1;
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| 181 | }
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| 182 |
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| 183 | return NULL;
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| 184 | }
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| 185 |
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| 186 | #endif
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| 187 |
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| 188 | static int tftp_protocol(
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| 189 | /* NULL if tftp, !NULL if tftpd: */
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| 190 | len_and_sockaddr *our_lsa,
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| 191 | len_and_sockaddr *peer_lsa,
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| 192 | const char *local_file
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| 193 | IF_TFTP(, const char *remote_file)
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| 194 | #if !ENABLE_TFTP
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| 195 | # define remote_file NULL
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| 196 | #endif
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| 197 | /* 1 for tftp; 1/0 for tftpd depending whether client asked about it: */
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| 198 | IF_FEATURE_TFTP_BLOCKSIZE(, int want_transfer_size)
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| 199 | IF_FEATURE_TFTP_BLOCKSIZE(, int blksize))
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| 200 | {
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| 201 | #if !ENABLE_FEATURE_TFTP_BLOCKSIZE
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| 202 | enum { blksize = TFTP_BLKSIZE_DEFAULT };
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| 203 | #endif
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| 204 |
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| 205 | struct pollfd pfd[1];
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| 206 | #define socket_fd (pfd[0].fd)
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| 207 | int len;
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| 208 | int send_len;
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| 209 | IF_FEATURE_TFTP_BLOCKSIZE(smallint expect_OACK = 0;)
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| 210 | smallint finished = 0;
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| 211 | uint16_t opcode;
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| 212 | uint16_t block_nr;
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| 213 | uint16_t recv_blk;
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| 214 | int open_mode, local_fd;
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| 215 | int retries, waittime_ms;
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| 216 | int io_bufsize = blksize + 4;
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| 217 | char *cp;
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| 218 | /* Can't use RESERVE_CONFIG_BUFFER here since the allocation
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| 219 | * size varies meaning BUFFERS_GO_ON_STACK would fail.
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| 220 | *
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| 221 | * We must keep the transmit and receive buffers separate
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| 222 | * in case we rcv a garbage pkt - we need to rexmit the last pkt.
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| 223 | */
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| 224 | char *xbuf = xmalloc(io_bufsize);
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| 225 | char *rbuf = xmalloc(io_bufsize);
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| 226 |
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| 227 | socket_fd = xsocket(peer_lsa->u.sa.sa_family, SOCK_DGRAM, 0);
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| 228 | setsockopt_reuseaddr(socket_fd);
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| 229 |
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| 230 | if (!ENABLE_TFTP || our_lsa) { /* tftpd */
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| 231 | /* Create a socket which is:
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| 232 | * 1. bound to IP:port peer sent 1st datagram to,
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| 233 | * 2. connected to peer's IP:port
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| 234 | * This way we will answer from the IP:port peer
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| 235 | * expects, will not get any other packets on
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| 236 | * the socket, and also plain read/write will work. */
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| 237 | xbind(socket_fd, &our_lsa->u.sa, our_lsa->len);
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| 238 | xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len);
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| 239 |
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| 240 | /* Is there an error already? Send pkt and bail out */
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| 241 | if (error_pkt_reason || error_pkt_str[0])
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| 242 | goto send_err_pkt;
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| 243 |
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| 244 | if (user_opt) {
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| 245 | struct passwd *pw = xgetpwnam(user_opt);
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| 246 | change_identity(pw); /* initgroups, setgid, setuid */
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| 247 | }
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| 248 | }
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| 249 |
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| 250 | /* Prepare open mode */
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| 251 | if (CMD_PUT(option_mask32)) {
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| 252 | open_mode = O_RDONLY;
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| 253 | } else {
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| 254 | open_mode = O_WRONLY | O_TRUNC | O_CREAT;
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| 255 | #if ENABLE_TFTPD
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| 256 | if ((option_mask32 & (TFTPD_OPT+TFTPD_OPT_c)) == TFTPD_OPT) {
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| 257 | /* tftpd without -c */
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| 258 | open_mode = O_WRONLY | O_TRUNC;
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| 259 | }
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| 260 | #endif
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| 261 | }
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| 262 |
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| 263 | /* Examples of network traffic.
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| 264 | * Note two cases when ACKs with block# of 0 are sent.
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| 265 | *
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| 266 | * Download without options:
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| 267 | * tftp -> "\0\1FILENAME\0octet\0"
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| 268 | * "\0\3\0\1FILEDATA..." <- tftpd
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| 269 | * tftp -> "\0\4\0\1"
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| 270 | * ...
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| 271 | * Download with option of blksize 16384:
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| 272 | * tftp -> "\0\1FILENAME\0octet\0blksize\00016384\0"
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| 273 | * "\0\6blksize\00016384\0" <- tftpd
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| 274 | * tftp -> "\0\4\0\0"
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| 275 | * "\0\3\0\1FILEDATA..." <- tftpd
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| 276 | * tftp -> "\0\4\0\1"
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| 277 | * ...
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| 278 | * Upload without options:
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| 279 | * tftp -> "\0\2FILENAME\0octet\0"
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| 280 | * "\0\4\0\0" <- tftpd
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| 281 | * tftp -> "\0\3\0\1FILEDATA..."
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| 282 | * "\0\4\0\1" <- tftpd
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| 283 | * ...
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| 284 | * Upload with option of blksize 16384:
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| 285 | * tftp -> "\0\2FILENAME\0octet\0blksize\00016384\0"
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| 286 | * "\0\6blksize\00016384\0" <- tftpd
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| 287 | * tftp -> "\0\3\0\1FILEDATA..."
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| 288 | * "\0\4\0\1" <- tftpd
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| 289 | * ...
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| 290 | */
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| 291 | block_nr = 1;
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| 292 | cp = xbuf + 2;
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| 293 |
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| 294 | if (!ENABLE_TFTP || our_lsa) { /* tftpd */
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| 295 | /* Open file (must be after changing user) */
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| 296 | local_fd = open(local_file, open_mode, 0666);
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| 297 | if (local_fd < 0) {
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| 298 | error_pkt_reason = ERR_NOFILE;
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| 299 | strcpy((char*)error_pkt_str, "can't open file");
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| 300 | goto send_err_pkt;
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| 301 | }
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| 302 | /* gcc 4.3.1 would NOT optimize it out as it should! */
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| 303 | #if ENABLE_FEATURE_TFTP_BLOCKSIZE
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| 304 | if (blksize != TFTP_BLKSIZE_DEFAULT || want_transfer_size) {
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| 305 | /* Create and send OACK packet. */
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| 306 | /* For the download case, block_nr is still 1 -
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| 307 | * we expect 1st ACK from peer to be for (block_nr-1),
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| 308 | * that is, for "block 0" which is our OACK pkt */
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| 309 | opcode = TFTP_OACK;
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| 310 | goto add_blksize_opt;
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| 311 | }
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| 312 | #endif
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| 313 | if (CMD_GET(option_mask32)) {
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| 314 | /* It's upload and we don't send OACK.
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| 315 | * We must ACK 1st packet (with filename)
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| 316 | * as if it is "block 0" */
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| 317 | block_nr = 0;
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| 318 | }
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| 319 |
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| 320 | } else { /* tftp */
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| 321 | /* Open file (must be after changing user) */
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| 322 | local_fd = CMD_GET(option_mask32) ? STDOUT_FILENO : STDIN_FILENO;
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| 323 | if (NOT_LONE_DASH(local_file))
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| 324 | local_fd = xopen(local_file, open_mode);
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| 325 | /* Removing #if, or using if() statement instead of #if may lead to
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| 326 | * "warning: null argument where non-null required": */
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| 327 | #if ENABLE_TFTP
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| 328 | /* tftp */
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| 329 |
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| 330 | /* We can't (and don't really need to) bind the socket:
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| 331 | * we don't know from which local IP datagrams will be sent,
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| 332 | * but kernel will pick the same IP every time (unless routing
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| 333 | * table is changed), thus peer will see dgrams consistently
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| 334 | * coming from the same IP.
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| 335 | * We would like to connect the socket, but since peer's
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| 336 | * UDP code can be less perfect than ours, _peer's_ IP:port
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| 337 | * in replies may differ from IP:port we used to send
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| 338 | * our first packet. We can connect() only when we get
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| 339 | * first reply. */
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| 340 |
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| 341 | /* build opcode */
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| 342 | opcode = TFTP_WRQ;
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| 343 | if (CMD_GET(option_mask32)) {
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| 344 | opcode = TFTP_RRQ;
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| 345 | }
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| 346 | /* add filename and mode */
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| 347 | /* fill in packet if the filename fits into xbuf */
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| 348 | len = strlen(remote_file) + 1;
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| 349 | if (2 + len + sizeof("octet") >= io_bufsize) {
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| 350 | bb_error_msg("remote filename is too long");
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| 351 | goto ret;
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| 352 | }
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| 353 | strcpy(cp, remote_file);
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| 354 | cp += len;
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| 355 | /* add "mode" part of the packet */
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| 356 | strcpy(cp, "octet");
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| 357 | cp += sizeof("octet");
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| 358 |
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| 359 | # if ENABLE_FEATURE_TFTP_BLOCKSIZE
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| 360 | if (blksize == TFTP_BLKSIZE_DEFAULT && !want_transfer_size)
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| 361 | goto send_pkt;
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| 362 |
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| 363 | /* Need to add option to pkt */
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| 364 | if ((&xbuf[io_bufsize - 1] - cp) < sizeof("blksize NNNNN tsize ") + sizeof(off_t)*3) {
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| 365 | bb_error_msg("remote filename is too long");
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| 366 | goto ret;
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| 367 | }
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| 368 | expect_OACK = 1;
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| 369 | # endif
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| 370 | #endif /* ENABLE_TFTP */
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| 371 |
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| 372 | #if ENABLE_FEATURE_TFTP_BLOCKSIZE
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| 373 | add_blksize_opt:
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| 374 | if (blksize != TFTP_BLKSIZE_DEFAULT) {
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| 375 | /* add "blksize", <nul>, blksize, <nul> */
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| 376 | strcpy(cp, "blksize");
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| 377 | cp += sizeof("blksize");
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| 378 | cp += snprintf(cp, 6, "%d", blksize) + 1;
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| 379 | }
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| 380 | if (want_transfer_size) {
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| 381 | /* add "tsize", <nul>, size, <nul> (see RFC2349) */
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| 382 | /* if tftp and downloading, we send "0" (since we opened local_fd with O_TRUNC)
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| 383 | * and this makes server to send "tsize" option with the size */
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| 384 | /* if tftp and uploading, we send file size (maybe dont, to not confuse old servers???) */
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| 385 | /* if tftpd and downloading, we are answering to client's request */
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| 386 | /* if tftpd and uploading: !want_transfer_size, this code is not executed */
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| 387 | struct stat st;
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| 388 | strcpy(cp, "tsize");
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| 389 | cp += sizeof("tsize");
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| 390 | st.st_size = 0;
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| 391 | fstat(local_fd, &st);
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| 392 | cp += sprintf(cp, "%"OFF_FMT"u", (off_t)st.st_size) + 1;
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| 393 | # if ENABLE_FEATURE_TFTP_PROGRESS_BAR
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| 394 | /* Save for progress bar. If 0 (tftp downloading),
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| 395 | * we look at server's reply later */
|
---|
| 396 | G.size = st.st_size;
|
---|
| 397 | if (remote_file && st.st_size)
|
---|
| 398 | tftp_progress_init();
|
---|
| 399 | # endif
|
---|
| 400 | }
|
---|
| 401 | #endif
|
---|
| 402 | /* First packet is built, so skip packet generation */
|
---|
| 403 | goto send_pkt;
|
---|
| 404 | }
|
---|
| 405 |
|
---|
| 406 | /* Using mostly goto's - continue/break will be less clear
|
---|
| 407 | * in where we actually jump to */
|
---|
| 408 | while (1) {
|
---|
| 409 | /* Build ACK or DATA */
|
---|
| 410 | cp = xbuf + 2;
|
---|
| 411 | *((uint16_t*)cp) = htons(block_nr);
|
---|
| 412 | cp += 2;
|
---|
| 413 | block_nr++;
|
---|
| 414 | opcode = TFTP_ACK;
|
---|
| 415 | if (CMD_PUT(option_mask32)) {
|
---|
| 416 | opcode = TFTP_DATA;
|
---|
| 417 | len = full_read(local_fd, cp, blksize);
|
---|
| 418 | if (len < 0) {
|
---|
| 419 | goto send_read_err_pkt;
|
---|
| 420 | }
|
---|
| 421 | if (len != blksize) {
|
---|
| 422 | finished = 1;
|
---|
| 423 | }
|
---|
| 424 | cp += len;
|
---|
| 425 | }
|
---|
| 426 | send_pkt:
|
---|
| 427 | /* Send packet */
|
---|
| 428 | *((uint16_t*)xbuf) = htons(opcode); /* fill in opcode part */
|
---|
| 429 | send_len = cp - xbuf;
|
---|
| 430 | /* NB: send_len value is preserved in code below
|
---|
| 431 | * for potential resend */
|
---|
| 432 |
|
---|
| 433 | retries = TFTP_NUM_RETRIES; /* re-initialize */
|
---|
| 434 | waittime_ms = TFTP_TIMEOUT_MS;
|
---|
| 435 |
|
---|
| 436 | send_again:
|
---|
| 437 | #if ENABLE_TFTP_DEBUG
|
---|
| 438 | fprintf(stderr, "sending %u bytes\n", send_len);
|
---|
| 439 | for (cp = xbuf; cp < &xbuf[send_len]; cp++)
|
---|
| 440 | fprintf(stderr, "%02x ", (unsigned char) *cp);
|
---|
| 441 | fprintf(stderr, "\n");
|
---|
| 442 | #endif
|
---|
| 443 | xsendto(socket_fd, xbuf, send_len, &peer_lsa->u.sa, peer_lsa->len);
|
---|
| 444 |
|
---|
| 445 | #if ENABLE_FEATURE_TFTP_PROGRESS_BAR
|
---|
| 446 | if (ENABLE_TFTP && remote_file) /* tftp */
|
---|
| 447 | G.pos = (block_nr - 1) * (uoff_t)blksize;
|
---|
| 448 | if (G.pmt.inited)
|
---|
| 449 | tftp_progress_update();
|
---|
| 450 | #endif
|
---|
| 451 | /* Was it final ACK? then exit */
|
---|
| 452 | if (finished && (opcode == TFTP_ACK))
|
---|
| 453 | goto ret;
|
---|
| 454 |
|
---|
| 455 | recv_again:
|
---|
| 456 | /* Receive packet */
|
---|
| 457 | /*pfd[0].fd = socket_fd;*/
|
---|
| 458 | pfd[0].events = POLLIN;
|
---|
| 459 | switch (safe_poll(pfd, 1, waittime_ms)) {
|
---|
| 460 | default:
|
---|
| 461 | /*bb_perror_msg("poll"); - done in safe_poll */
|
---|
| 462 | goto ret;
|
---|
| 463 | case 0:
|
---|
| 464 | retries--;
|
---|
| 465 | if (retries == 0) {
|
---|
| 466 | tftp_progress_done();
|
---|
| 467 | bb_error_msg("timeout");
|
---|
| 468 | goto ret; /* no err packet sent */
|
---|
| 469 | }
|
---|
| 470 |
|
---|
| 471 | /* exponential backoff with limit */
|
---|
| 472 | waittime_ms += waittime_ms/2;
|
---|
| 473 | if (waittime_ms > TFTP_MAXTIMEOUT_MS) {
|
---|
| 474 | waittime_ms = TFTP_MAXTIMEOUT_MS;
|
---|
| 475 | }
|
---|
| 476 |
|
---|
| 477 | goto send_again; /* resend last sent pkt */
|
---|
| 478 | case 1:
|
---|
| 479 | if (!our_lsa) {
|
---|
| 480 | /* tftp (not tftpd!) receiving 1st packet */
|
---|
| 481 | our_lsa = ((void*)(ptrdiff_t)-1); /* not NULL */
|
---|
| 482 | len = recvfrom(socket_fd, rbuf, io_bufsize, 0,
|
---|
| 483 | &peer_lsa->u.sa, &peer_lsa->len);
|
---|
| 484 | /* Our first dgram went to port 69
|
---|
| 485 | * but reply may come from different one.
|
---|
| 486 | * Remember and use this new port (and IP) */
|
---|
| 487 | if (len >= 0)
|
---|
| 488 | xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len);
|
---|
| 489 | } else {
|
---|
| 490 | /* tftpd, or not the very first packet:
|
---|
| 491 | * socket is connect()ed, can just read from it. */
|
---|
| 492 | /* Don't full_read()!
|
---|
| 493 | * This is not TCP, one read == one pkt! */
|
---|
| 494 | len = safe_read(socket_fd, rbuf, io_bufsize);
|
---|
| 495 | }
|
---|
| 496 | if (len < 0) {
|
---|
| 497 | goto send_read_err_pkt;
|
---|
| 498 | }
|
---|
| 499 | if (len < 4) { /* too small? */
|
---|
| 500 | goto recv_again;
|
---|
| 501 | }
|
---|
| 502 | }
|
---|
| 503 |
|
---|
| 504 | /* Process recv'ed packet */
|
---|
| 505 | opcode = ntohs( ((uint16_t*)rbuf)[0] );
|
---|
| 506 | recv_blk = ntohs( ((uint16_t*)rbuf)[1] );
|
---|
| 507 | #if ENABLE_TFTP_DEBUG
|
---|
| 508 | fprintf(stderr, "received %d bytes: %04x %04x\n", len, opcode, recv_blk);
|
---|
| 509 | #endif
|
---|
| 510 | if (opcode == TFTP_ERROR) {
|
---|
| 511 | static const char errcode_str[] ALIGN1 =
|
---|
| 512 | "\0"
|
---|
| 513 | "file not found\0"
|
---|
| 514 | "access violation\0"
|
---|
| 515 | "disk full\0"
|
---|
| 516 | "bad operation\0"
|
---|
| 517 | "unknown transfer id\0"
|
---|
| 518 | "file already exists\0"
|
---|
| 519 | "no such user\0"
|
---|
| 520 | "bad option";
|
---|
| 521 |
|
---|
| 522 | const char *msg = "";
|
---|
| 523 |
|
---|
| 524 | if (len > 4 && rbuf[4] != '\0') {
|
---|
| 525 | msg = &rbuf[4];
|
---|
| 526 | rbuf[io_bufsize - 1] = '\0'; /* paranoia */
|
---|
| 527 | } else if (recv_blk <= 8) {
|
---|
| 528 | msg = nth_string(errcode_str, recv_blk);
|
---|
| 529 | }
|
---|
| 530 | bb_error_msg("server error: (%u) %s", recv_blk, msg);
|
---|
| 531 | goto ret;
|
---|
| 532 | }
|
---|
| 533 |
|
---|
| 534 | #if ENABLE_FEATURE_TFTP_BLOCKSIZE
|
---|
| 535 | if (expect_OACK) {
|
---|
| 536 | expect_OACK = 0;
|
---|
| 537 | if (opcode == TFTP_OACK) {
|
---|
| 538 | /* server seems to support options */
|
---|
| 539 | char *res;
|
---|
| 540 |
|
---|
| 541 | res = tftp_get_option("blksize", &rbuf[2], len - 2);
|
---|
| 542 | if (res) {
|
---|
| 543 | blksize = tftp_blksize_check(res, blksize);
|
---|
| 544 | if (blksize < 0) {
|
---|
| 545 | error_pkt_reason = ERR_BAD_OPT;
|
---|
| 546 | goto send_err_pkt;
|
---|
| 547 | }
|
---|
| 548 | io_bufsize = blksize + 4;
|
---|
| 549 | }
|
---|
| 550 | # if ENABLE_FEATURE_TFTP_PROGRESS_BAR
|
---|
| 551 | if (remote_file && G.size == 0) { /* if we don't know it yet */
|
---|
| 552 | res = tftp_get_option("tsize", &rbuf[2], len - 2);
|
---|
| 553 | if (res) {
|
---|
| 554 | G.size = bb_strtoull(res, NULL, 10);
|
---|
| 555 | if (G.size)
|
---|
| 556 | tftp_progress_init();
|
---|
| 557 | }
|
---|
| 558 | }
|
---|
| 559 | # endif
|
---|
| 560 | if (CMD_GET(option_mask32)) {
|
---|
| 561 | /* We'll send ACK for OACK,
|
---|
| 562 | * such ACK has "block no" of 0 */
|
---|
| 563 | block_nr = 0;
|
---|
| 564 | }
|
---|
| 565 | continue;
|
---|
| 566 | }
|
---|
| 567 | /* rfc2347:
|
---|
| 568 | * "An option not acknowledged by the server
|
---|
| 569 | * must be ignored by the client and server
|
---|
| 570 | * as if it were never requested." */
|
---|
| 571 | if (blksize != TFTP_BLKSIZE_DEFAULT)
|
---|
| 572 | bb_error_msg("falling back to blocksize "TFTP_BLKSIZE_DEFAULT_STR);
|
---|
| 573 | blksize = TFTP_BLKSIZE_DEFAULT;
|
---|
| 574 | io_bufsize = TFTP_BLKSIZE_DEFAULT + 4;
|
---|
| 575 | }
|
---|
| 576 | #endif
|
---|
| 577 | /* block_nr is already advanced to next block# we expect
|
---|
| 578 | * to get / block# we are about to send next time */
|
---|
| 579 |
|
---|
| 580 | if (CMD_GET(option_mask32) && (opcode == TFTP_DATA)) {
|
---|
| 581 | if (recv_blk == block_nr) {
|
---|
| 582 | int sz = full_write(local_fd, &rbuf[4], len - 4);
|
---|
| 583 | if (sz != len - 4) {
|
---|
| 584 | strcpy((char*)error_pkt_str, bb_msg_write_error);
|
---|
| 585 | error_pkt_reason = ERR_WRITE;
|
---|
| 586 | goto send_err_pkt;
|
---|
| 587 | }
|
---|
| 588 | if (sz != blksize) {
|
---|
| 589 | finished = 1;
|
---|
| 590 | }
|
---|
| 591 | continue; /* send ACK */
|
---|
| 592 | }
|
---|
| 593 | /* Disabled to cope with servers with Sorcerer's Apprentice Syndrome */
|
---|
| 594 | #if 0
|
---|
| 595 | if (recv_blk == (block_nr - 1)) {
|
---|
| 596 | /* Server lost our TFTP_ACK. Resend it */
|
---|
| 597 | block_nr = recv_blk;
|
---|
| 598 | continue;
|
---|
| 599 | }
|
---|
| 600 | #endif
|
---|
| 601 | }
|
---|
| 602 |
|
---|
| 603 | if (CMD_PUT(option_mask32) && (opcode == TFTP_ACK)) {
|
---|
| 604 | /* did peer ACK our last DATA pkt? */
|
---|
| 605 | if (recv_blk == (uint16_t) (block_nr - 1)) {
|
---|
| 606 | if (finished)
|
---|
| 607 | goto ret;
|
---|
| 608 | continue; /* send next block */
|
---|
| 609 | }
|
---|
| 610 | }
|
---|
| 611 | /* Awww... recv'd packet is not recognized! */
|
---|
| 612 | goto recv_again;
|
---|
| 613 | /* why recv_again? - rfc1123 says:
|
---|
| 614 | * "The sender (i.e., the side originating the DATA packets)
|
---|
| 615 | * must never resend the current DATA packet on receipt
|
---|
| 616 | * of a duplicate ACK".
|
---|
| 617 | * DATA pkts are resent ONLY on timeout.
|
---|
| 618 | * Thus "goto send_again" will ba a bad mistake above.
|
---|
| 619 | * See:
|
---|
| 620 | * http://en.wikipedia.org/wiki/Sorcerer's_Apprentice_Syndrome
|
---|
| 621 | */
|
---|
| 622 | } /* end of "while (1)" */
|
---|
| 623 | ret:
|
---|
| 624 | if (ENABLE_FEATURE_CLEAN_UP) {
|
---|
| 625 | close(local_fd);
|
---|
| 626 | close(socket_fd);
|
---|
| 627 | free(xbuf);
|
---|
| 628 | free(rbuf);
|
---|
| 629 | }
|
---|
| 630 | return finished == 0; /* returns 1 on failure */
|
---|
| 631 |
|
---|
| 632 | send_read_err_pkt:
|
---|
| 633 | strcpy((char*)error_pkt_str, bb_msg_read_error);
|
---|
| 634 | send_err_pkt:
|
---|
| 635 | if (error_pkt_str[0])
|
---|
| 636 | bb_error_msg("%s", (char*)error_pkt_str);
|
---|
| 637 | error_pkt[1] = TFTP_ERROR;
|
---|
| 638 | xsendto(socket_fd, error_pkt, 4 + 1 + strlen((char*)error_pkt_str),
|
---|
| 639 | &peer_lsa->u.sa, peer_lsa->len);
|
---|
| 640 | return EXIT_FAILURE;
|
---|
| 641 | #undef remote_file
|
---|
| 642 | }
|
---|
| 643 |
|
---|
| 644 | #if ENABLE_TFTP
|
---|
| 645 |
|
---|
| 646 | int tftp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
---|
| 647 | int tftp_main(int argc UNUSED_PARAM, char **argv)
|
---|
| 648 | {
|
---|
| 649 | len_and_sockaddr *peer_lsa;
|
---|
| 650 | const char *local_file = NULL;
|
---|
| 651 | const char *remote_file = NULL;
|
---|
| 652 | # if ENABLE_FEATURE_TFTP_BLOCKSIZE
|
---|
| 653 | const char *blksize_str = TFTP_BLKSIZE_DEFAULT_STR;
|
---|
| 654 | int blksize;
|
---|
| 655 | # endif
|
---|
| 656 | int result;
|
---|
| 657 | int port;
|
---|
| 658 | IF_GETPUT(int opt;)
|
---|
| 659 |
|
---|
| 660 | INIT_G();
|
---|
| 661 |
|
---|
| 662 | /* -p or -g is mandatory, and they are mutually exclusive */
|
---|
| 663 | opt_complementary = "" IF_FEATURE_TFTP_GET("g:") IF_FEATURE_TFTP_PUT("p:")
|
---|
| 664 | IF_GETPUT("g--p:p--g:");
|
---|
| 665 |
|
---|
| 666 | IF_GETPUT(opt =) getopt32(argv,
|
---|
| 667 | IF_FEATURE_TFTP_GET("g") IF_FEATURE_TFTP_PUT("p")
|
---|
| 668 | "l:r:" IF_FEATURE_TFTP_BLOCKSIZE("b:"),
|
---|
| 669 | &local_file, &remote_file
|
---|
| 670 | IF_FEATURE_TFTP_BLOCKSIZE(, &blksize_str));
|
---|
| 671 | argv += optind;
|
---|
| 672 |
|
---|
| 673 | # if ENABLE_FEATURE_TFTP_BLOCKSIZE
|
---|
| 674 | /* Check if the blksize is valid:
|
---|
| 675 | * RFC2348 says between 8 and 65464 */
|
---|
| 676 | blksize = tftp_blksize_check(blksize_str, 65564);
|
---|
| 677 | if (blksize < 0) {
|
---|
| 678 | //bb_error_msg("bad block size");
|
---|
| 679 | return EXIT_FAILURE;
|
---|
| 680 | }
|
---|
| 681 | # endif
|
---|
| 682 |
|
---|
| 683 | if (remote_file) {
|
---|
| 684 | if (!local_file) {
|
---|
| 685 | const char *slash = strrchr(remote_file, '/');
|
---|
| 686 | local_file = slash ? slash + 1 : remote_file;
|
---|
| 687 | }
|
---|
| 688 | } else {
|
---|
| 689 | remote_file = local_file;
|
---|
| 690 | }
|
---|
| 691 |
|
---|
| 692 | /* Error if filename or host is not known */
|
---|
| 693 | if (!remote_file || !argv[0])
|
---|
| 694 | bb_show_usage();
|
---|
| 695 |
|
---|
| 696 | port = bb_lookup_port(argv[1], "udp", 69);
|
---|
| 697 | peer_lsa = xhost2sockaddr(argv[0], port);
|
---|
| 698 |
|
---|
| 699 | # if ENABLE_TFTP_DEBUG
|
---|
| 700 | fprintf(stderr, "using server '%s', remote_file '%s', local_file '%s'\n",
|
---|
| 701 | xmalloc_sockaddr2dotted(&peer_lsa->u.sa),
|
---|
| 702 | remote_file, local_file);
|
---|
| 703 | # endif
|
---|
| 704 |
|
---|
| 705 | # if ENABLE_FEATURE_TFTP_PROGRESS_BAR
|
---|
| 706 | G.file = remote_file;
|
---|
| 707 | # endif
|
---|
| 708 | result = tftp_protocol(
|
---|
| 709 | NULL /*our_lsa*/, peer_lsa,
|
---|
| 710 | local_file, remote_file
|
---|
| 711 | IF_FEATURE_TFTP_BLOCKSIZE(, 1 /* want_transfer_size */)
|
---|
| 712 | IF_FEATURE_TFTP_BLOCKSIZE(, blksize)
|
---|
| 713 | );
|
---|
| 714 | tftp_progress_done();
|
---|
| 715 |
|
---|
| 716 | if (result != EXIT_SUCCESS && NOT_LONE_DASH(local_file) && CMD_GET(opt)) {
|
---|
| 717 | unlink(local_file);
|
---|
| 718 | }
|
---|
| 719 | return result;
|
---|
| 720 | }
|
---|
| 721 |
|
---|
| 722 | #endif /* ENABLE_TFTP */
|
---|
| 723 |
|
---|
| 724 | #if ENABLE_TFTPD
|
---|
| 725 | int tftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
---|
| 726 | int tftpd_main(int argc UNUSED_PARAM, char **argv)
|
---|
| 727 | {
|
---|
| 728 | len_and_sockaddr *our_lsa;
|
---|
| 729 | len_and_sockaddr *peer_lsa;
|
---|
| 730 | char *local_file, *mode;
|
---|
| 731 | const char *error_msg;
|
---|
| 732 | int opt, result, opcode;
|
---|
| 733 | IF_FEATURE_TFTP_BLOCKSIZE(int blksize = TFTP_BLKSIZE_DEFAULT;)
|
---|
| 734 | IF_FEATURE_TFTP_BLOCKSIZE(int want_transfer_size = 0;)
|
---|
| 735 |
|
---|
| 736 | INIT_G();
|
---|
| 737 |
|
---|
| 738 | our_lsa = get_sock_lsa(STDIN_FILENO);
|
---|
| 739 | if (!our_lsa) {
|
---|
| 740 | /* This is confusing:
|
---|
| 741 | *bb_error_msg_and_die("stdin is not a socket");
|
---|
| 742 | * Better: */
|
---|
| 743 | bb_show_usage();
|
---|
| 744 | /* Help text says that tftpd must be used as inetd service,
|
---|
| 745 | * which is by far the most usual cause of get_sock_lsa
|
---|
| 746 | * failure */
|
---|
| 747 | }
|
---|
| 748 | peer_lsa = xzalloc(LSA_LEN_SIZE + our_lsa->len);
|
---|
| 749 | peer_lsa->len = our_lsa->len;
|
---|
| 750 |
|
---|
| 751 | /* Shifting to not collide with TFTP_OPTs */
|
---|
| 752 | opt = option_mask32 = TFTPD_OPT | (getopt32(argv, "rcu:", &user_opt) << 8);
|
---|
| 753 | argv += optind;
|
---|
| 754 | if (argv[0])
|
---|
| 755 | xchdir(argv[0]);
|
---|
| 756 |
|
---|
| 757 | result = recv_from_to(STDIN_FILENO, block_buf, sizeof(block_buf),
|
---|
| 758 | 0 /* flags */,
|
---|
| 759 | &peer_lsa->u.sa, &our_lsa->u.sa, our_lsa->len);
|
---|
| 760 |
|
---|
| 761 | error_msg = "malformed packet";
|
---|
| 762 | opcode = ntohs(*(uint16_t*)block_buf);
|
---|
| 763 | if (result < 4 || result >= sizeof(block_buf)
|
---|
| 764 | || block_buf[result-1] != '\0'
|
---|
| 765 | || (IF_FEATURE_TFTP_PUT(opcode != TFTP_RRQ) /* not download */
|
---|
| 766 | IF_GETPUT(&&)
|
---|
| 767 | IF_FEATURE_TFTP_GET(opcode != TFTP_WRQ) /* not upload */
|
---|
| 768 | )
|
---|
| 769 | ) {
|
---|
| 770 | goto err;
|
---|
| 771 | }
|
---|
| 772 | local_file = block_buf + 2;
|
---|
| 773 | if (local_file[0] == '.' || strstr(local_file, "/.")) {
|
---|
| 774 | error_msg = "dot in file name";
|
---|
| 775 | goto err;
|
---|
| 776 | }
|
---|
| 777 | mode = local_file + strlen(local_file) + 1;
|
---|
| 778 | if (mode >= block_buf + result || strcmp(mode, "octet") != 0) {
|
---|
| 779 | goto err;
|
---|
| 780 | }
|
---|
| 781 | # if ENABLE_FEATURE_TFTP_BLOCKSIZE
|
---|
| 782 | {
|
---|
| 783 | char *res;
|
---|
| 784 | char *opt_str = mode + sizeof("octet");
|
---|
| 785 | int opt_len = block_buf + result - opt_str;
|
---|
| 786 | if (opt_len > 0) {
|
---|
| 787 | res = tftp_get_option("blksize", opt_str, opt_len);
|
---|
| 788 | if (res) {
|
---|
| 789 | blksize = tftp_blksize_check(res, 65564);
|
---|
| 790 | if (blksize < 0) {
|
---|
| 791 | error_pkt_reason = ERR_BAD_OPT;
|
---|
| 792 | /* will just send error pkt */
|
---|
| 793 | goto do_proto;
|
---|
| 794 | }
|
---|
| 795 | }
|
---|
| 796 | if (opcode != TFTP_WRQ /* download? */
|
---|
| 797 | /* did client ask us about file size? */
|
---|
| 798 | && tftp_get_option("tsize", opt_str, opt_len)
|
---|
| 799 | ) {
|
---|
| 800 | want_transfer_size = 1;
|
---|
| 801 | }
|
---|
| 802 | }
|
---|
| 803 | }
|
---|
| 804 | # endif
|
---|
| 805 |
|
---|
| 806 | if (!ENABLE_FEATURE_TFTP_PUT || opcode == TFTP_WRQ) {
|
---|
| 807 | if (opt & TFTPD_OPT_r) {
|
---|
| 808 | /* This would mean "disk full" - not true */
|
---|
| 809 | /*error_pkt_reason = ERR_WRITE;*/
|
---|
| 810 | error_msg = bb_msg_write_error;
|
---|
| 811 | goto err;
|
---|
| 812 | }
|
---|
| 813 | IF_GETPUT(option_mask32 |= TFTP_OPT_GET;) /* will receive file's data */
|
---|
| 814 | } else {
|
---|
| 815 | IF_GETPUT(option_mask32 |= TFTP_OPT_PUT;) /* will send file's data */
|
---|
| 816 | }
|
---|
| 817 |
|
---|
| 818 | /* NB: if error_pkt_str or error_pkt_reason is set up,
|
---|
| 819 | * tftp_protocol() just sends one error pkt and returns */
|
---|
| 820 |
|
---|
| 821 | do_proto:
|
---|
| 822 | close(STDIN_FILENO); /* close old, possibly wildcard socket */
|
---|
| 823 | /* tftp_protocol() will create new one, bound to particular local IP */
|
---|
| 824 | result = tftp_protocol(
|
---|
| 825 | our_lsa, peer_lsa,
|
---|
| 826 | local_file IF_TFTP(, NULL /*remote_file*/)
|
---|
| 827 | IF_FEATURE_TFTP_BLOCKSIZE(, want_transfer_size)
|
---|
| 828 | IF_FEATURE_TFTP_BLOCKSIZE(, blksize)
|
---|
| 829 | );
|
---|
| 830 |
|
---|
| 831 | return result;
|
---|
| 832 | err:
|
---|
| 833 | strcpy((char*)error_pkt_str, error_msg);
|
---|
| 834 | goto do_proto;
|
---|
| 835 | }
|
---|
| 836 |
|
---|
| 837 | #endif /* ENABLE_TFTPD */
|
---|
| 838 |
|
---|
| 839 | #endif /* ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT */
|
---|