diff options
| -rw-r--r-- | include/usage.h | 6 | ||||
| -rw-r--r-- | networking/tftp.c | 147 |
2 files changed, 88 insertions, 65 deletions
diff --git a/include/usage.h b/include/usage.h index 7fe9ad0..ad90097 100644 --- a/include/usage.h +++ b/include/usage.h @@ -3977,11 +3977,13 @@ ) #define tftpd_trivial_usage \ - "[-r] [DIR]" + "[-cr] [-u USER] [DIR]" #define tftpd_full_usage \ - "Transfer a file on request from a tftp client.\n" \ + "Transfer a file on tftp client's request.\n" \ "\nOptions:" \ "\n -r Prohibit upload" \ + "\n -c Allow file creation via upload" \ + "\n -u Access files as USER" \ #define time_trivial_usage \ "[OPTION]... COMMAND [ARGS...]" diff --git a/networking/tftp.c b/networking/tftp.c index e0f2b91..5fac487 100644 --- a/networking/tftp.c +++ b/networking/tftp.c @@ -51,6 +51,17 @@ #define ERR_BAD_USER 7 #define ERR_BAD_OPT 8 +/* masks coming from getopt32 */ +enum { + TFTP_OPT_GET = (1 << 0), + TFTP_OPT_PUT = (1 << 1), + /* pseudo option: if set, it's tftpd */ + TFTPD_OPT = (1 << 7) * ENABLE_TFTPD, + TFTPD_OPT_r = (1 << 8) * ENABLE_TFTPD, + TFTPD_OPT_c = (1 << 9) * ENABLE_TFTPD, + TFTPD_OPT_u = (1 << 10) * ENABLE_TFTPD, +}; + #if ENABLE_FEATURE_TFTP_GET && !ENABLE_FEATURE_TFTP_PUT #define USE_GETPUT(...) #define CMD_GET(cmd) 1 @@ -61,9 +72,8 @@ #define CMD_PUT(cmd) 1 #else #define USE_GETPUT(...) __VA_ARGS__ -/* masks coming from getopt32 */ -#define CMD_GET(cmd) ((cmd) & 1) -#define CMD_PUT(cmd) ((cmd) & 2) +#define CMD_GET(cmd) ((cmd) & TFTP_OPT_GET) +#define CMD_PUT(cmd) ((cmd) & TFTP_OPT_PUT) #endif /* NB: in the code below * CMD_GET(cmd) and CMD_PUT(cmd) are mutually exclusive @@ -73,11 +83,15 @@ struct globals { /* u16 TFTP_ERROR; u16 reason; both network-endian, then error text: */ uint8_t error_pkt[4 + 32]; +#if ENABLE_TFTPD + char *user_opt; +#endif /* used in tftpd_main(), a bit big for stack: */ char block_buf[TFTP_BLKSIZE_DEFAULT]; }; #define G (*(struct globals*)&bb_common_bufsiz1) #define block_buf (G.block_buf ) +#define user_opt (G.user_opt ) #define error_pkt (G.error_pkt ) #define INIT_G() \ do { \ @@ -148,11 +162,10 @@ static char *tftp_get_blksize(char *buf, int len) #endif static int tftp_protocol( - USE_GETPUT(int cmd,) len_and_sockaddr *our_lsa, len_and_sockaddr *peer_lsa, + const char *local_file, USE_TFTP(const char *remote_file,) - int local_fd, int blksize) { #if !ENABLE_TFTP @@ -167,6 +180,7 @@ static int tftp_protocol( uint16_t opcode; uint16_t block_nr; uint16_t recv_blk; + int open_mode, local_fd; int retries, waittime_ms; int io_bufsize = blksize + 4; char *cp; @@ -180,6 +194,39 @@ static int tftp_protocol( socket_fd = xsocket(peer_lsa->u.sa.sa_family, SOCK_DGRAM, 0); setsockopt_reuseaddr(socket_fd); +#if ENABLE_TFTPD + if (user_opt) { + struct passwd *pw = getpwnam(user_opt); /* initgroups, setgid, setuid */ + if (!pw) + bb_error_msg_and_die("unknown user '%s'", user_opt); + change_identity(pw); + } +#endif + + if (CMD_PUT(option_mask32)) { + open_mode = O_RDONLY; + } else { + open_mode = O_WRONLY | O_TRUNC | O_CREAT; +#if ENABLE_TFTPD + if ((option_mask32 & (TFTPD_OPT+TFTPD_OPT_c)) == TFTPD_OPT) { + /* tftpd without -c */ + open_mode = O_WRONLY | O_TRUNC; + } +#endif + } + if (!(option_mask32 & TFTPD_OPT)) { + local_fd = CMD_GET(option_mask32) ? STDOUT_FILENO : STDIN_FILENO; + if (NOT_LONE_DASH(local_file)) + local_fd = xopen(local_file, open_mode); + } else { + local_fd = open_or_warn(local_file, open_mode); + if (local_fd < 0) { + /*error_pkt_reason = ERR_NOFILE/ERR_ACCESS?*/ + strcpy(error_pkt_str, "can't open file"); + goto send_err_pkt; + } + } + block_nr = 1; if (!ENABLE_TFTP || our_lsa) { /* tftpd */ @@ -197,7 +244,7 @@ static int tftp_protocol( if (error_pkt_reason || error_pkt_str[0]) goto send_err_pkt; - if (CMD_GET(cmd)) { + if (CMD_GET(option_mask32)) { /* it's upload - we must ACK 1st packet (with filename) * as if it's "block 0" */ block_nr = 0; @@ -231,7 +278,7 @@ static int tftp_protocol( /* build opcode */ opcode = TFTP_WRQ; - if (CMD_GET(cmd)) { + if (CMD_GET(option_mask32)) { opcode = TFTP_RRQ; } cp = xbuf + 2; @@ -276,7 +323,7 @@ static int tftp_protocol( cp += 2; block_nr++; opcode = TFTP_ACK; - if (CMD_PUT(cmd)) { + if (CMD_PUT(option_mask32)) { opcode = TFTP_DATA; len = full_read(local_fd, cp, blksize); if (len < 0) { @@ -420,7 +467,7 @@ static int tftp_protocol( /* block_nr is already advanced to next block# we expect * to get / block# we are about to send next time */ - if (CMD_GET(cmd) && (opcode == TFTP_DATA)) { + if (CMD_GET(option_mask32) && (opcode == TFTP_DATA)) { if (recv_blk == block_nr) { int sz = full_write(local_fd, &rbuf[4], len - 4); if (sz != len - 4) { @@ -440,7 +487,7 @@ static int tftp_protocol( } } - if (CMD_PUT(cmd) && (opcode == TFTP_ACK)) { + if (CMD_PUT(option_mask32) && (opcode == TFTP_ACK)) { /* did peer ACK our last DATA pkt? */ if (recv_blk == (uint16_t) (block_nr - 1)) { if (finished) @@ -462,6 +509,7 @@ static int tftp_protocol( } /* end of "while (1)" */ ret: if (ENABLE_FEATURE_CLEAN_UP) { + close(local_fd); close(socket_fd); free(xbuf); free(rbuf); @@ -487,13 +535,11 @@ int tftp_main(int argc ATTRIBUTE_UNUSED, char **argv) len_and_sockaddr *peer_lsa; const char *local_file = NULL; const char *remote_file = NULL; - int port; - USE_GETPUT(int cmd;) - int local_fd; - int flags = 0; - int result; - int blksize; const char *blksize_str = "512"; + int blksize; + int result; + int port; + USE_GETPUT(int opt;) INIT_G(); @@ -501,17 +547,13 @@ int tftp_main(int argc ATTRIBUTE_UNUSED, char **argv) opt_complementary = "" USE_FEATURE_TFTP_GET("g:") USE_FEATURE_TFTP_PUT("p:") USE_GETPUT("g--p:p--g:"); - USE_GETPUT(cmd =) getopt32(argv, + USE_GETPUT(opt =) getopt32(argv, USE_FEATURE_TFTP_GET("g") USE_FEATURE_TFTP_PUT("p") "l:r:" USE_FEATURE_TFTP_BLOCKSIZE("b:"), &local_file, &remote_file USE_FEATURE_TFTP_BLOCKSIZE(, &blksize_str)); argv += optind; - flags = O_RDONLY; - if (CMD_GET(cmd)) - flags = O_WRONLY | O_CREAT | O_TRUNC; - #if ENABLE_FEATURE_TFTP_BLOCKSIZE /* Check if the blksize is valid: * RFC2348 says between 8 and 65464 */ @@ -530,11 +572,6 @@ int tftp_main(int argc ATTRIBUTE_UNUSED, char **argv) if (!remote_file || !argv[0]) bb_show_usage(); - local_fd = CMD_GET(cmd) ? STDOUT_FILENO : STDIN_FILENO; - if (!LONE_DASH(local_file)) { - local_fd = xopen(local_file, flags); - } - port = bb_lookup_port(argv[1], "udp", 69); peer_lsa = xhost2sockaddr(argv[0], port); @@ -545,14 +582,11 @@ int tftp_main(int argc ATTRIBUTE_UNUSED, char **argv) #endif result = tftp_protocol( - USE_GETPUT(cmd,) - NULL /* our_lsa*/, - peer_lsa, - remote_file, local_fd, blksize); + NULL /* our_lsa*/, peer_lsa, + local_file, remote_file, + blksize); - if (ENABLE_FEATURE_CLEAN_UP) - close(local_fd); - if (result != EXIT_SUCCESS && !LONE_DASH(local_file) && CMD_GET(cmd)) { + if (result != EXIT_SUCCESS && NOT_LONE_DASH(local_file) && CMD_GET(opt)) { unlink(local_file); } return result; @@ -581,9 +615,9 @@ int tftpd_main(int argc ATTRIBUTE_UNUSED, char **argv) { len_and_sockaddr *our_lsa; len_and_sockaddr *peer_lsa; - char *filename, *mode; + char *local_file, *mode; const char *error_msg; - int opt_r, result, opcode, open_mode; + int opt, result, opcode; int local_fd = local_fd; /* for compiler */ int blksize = blksize; USE_GETPUT(int cmd = cmd;) @@ -596,7 +630,8 @@ int tftpd_main(int argc ATTRIBUTE_UNUSED, char **argv) peer_lsa = xzalloc(LSA_LEN_SIZE + our_lsa->len); peer_lsa->len = our_lsa->len; - opt_r = getopt32(argv, "r"); + /* Shifting to not collide with TFTP_OPTs */ + opt = option_mask32 = TFTPD_OPT | (getopt32(argv, "rcu:", &user_opt) << 8); argv += optind; if (argv[0]) xchdir(argv[0]); @@ -616,15 +651,13 @@ int tftpd_main(int argc ATTRIBUTE_UNUSED, char **argv) ) { goto err; } - filename = block_buf + 2; - if (filename[0] == '.' || strstr(filename, "/.")) { - error_msg = "dot in filename"; + local_file = block_buf + 2; + if (local_file[0] == '.' || strstr(local_file, "/.")) { + error_msg = "dot in local_file"; goto err; } - mode = filename + strlen(filename) + 1; - if (mode >= block_buf + result - || strcmp(mode, "octet") != 0 - ) { + mode = local_file + strlen(local_file) + 1; + if (mode >= block_buf + result || strcmp(mode, "octet") != 0) { goto err; } blksize = TFTP_BLKSIZE_DEFAULT; @@ -647,29 +680,16 @@ int tftpd_main(int argc ATTRIBUTE_UNUSED, char **argv) } #endif -#if ENABLE_FEATURE_TFTP_PUT - /* in case opcode is TFTP_RRQ: */ - USE_GETPUT(cmd = 2;) /* CMD_PUT: we will send file's data */ - open_mode = O_RDONLY; -#endif -#if ENABLE_FEATURE_TFTP_GET if (!ENABLE_FEATURE_TFTP_PUT || opcode == TFTP_WRQ) { - if (opt_r) { + if (opt & TFTPD_OPT_r) { /* This would mean "disk full" - not true */ /*error_pkt_reason = ERR_WRITE;*/ error_msg = bb_msg_write_error; goto err; } - USE_GETPUT(cmd = 1;) /* CMD_GET: we will receive file's data */ - open_mode = O_WRONLY | O_TRUNC; - } -#endif - local_fd = open(filename, open_mode); - if (local_fd < 0) { - /*error_pkt_reason = ERR_NOFILE/ERR_ACCESS?*/ - error_msg = "can't open file"; - err: - strcpy(error_pkt_str, error_msg); + USE_GETPUT(option_mask32 |= TFTP_OPT_GET;) /* will receive file's data */ + } else { + USE_GETPUT(option_mask32 |= TFTP_OPT_PUT;) /* will send file's data */ } close(STDIN_FILENO); /* close old, possibly wildcard socket */ @@ -679,14 +699,15 @@ int tftpd_main(int argc ATTRIBUTE_UNUSED, char **argv) * tftp_protocol() just sends one error pkt and returns */ do_proto: result = tftp_protocol( - USE_GETPUT(cmd,) our_lsa, peer_lsa, - USE_TFTP(NULL /*remote_file*/,) - local_fd, + local_file, USE_TFTP(NULL /*remote_file*/,) blksize ); return result; + err: + strcpy(error_pkt_str, error_msg); + goto do_proto; } #endif /* ENABLE_TFTPD */ |