diff options
| -rw-r--r-- | include/usage.h | 6 | ||||
| -rw-r--r-- | networking/tftp.c | 48 |
2 files changed, 31 insertions, 23 deletions
diff --git a/include/usage.h b/include/usage.h index 1fa40ce..7fe9ad0 100644 --- a/include/usage.h +++ b/include/usage.h @@ -3977,9 +3977,11 @@ ) #define tftpd_trivial_usage \ - "[DIR]" + "[-r] [DIR]" #define tftpd_full_usage \ - "Transfer a file on request from a tftp client" \ + "Transfer a file on request from a tftp client.\n" \ + "\nOptions:" \ + "\n -r Prohibit upload" \ #define time_trivial_usage \ "[OPTION]... COMMAND [ARGS...]" diff --git a/networking/tftp.c b/networking/tftp.c index 25001c2..3075ab0 100644 --- a/networking/tftp.c +++ b/networking/tftp.c @@ -56,6 +56,8 @@ * CMD_GET(cmd) and CMD_PUT(cmd) are mutually exclusive */ +// TODO: emit error packets before dying + #if ENABLE_FEATURE_TFTP_BLOCKSIZE @@ -340,7 +342,7 @@ static int tftp_protocol( const char *msg = ""; - if (rbuf[4] != '\0') { + if (len > 4 && rbuf[4] != '\0') { msg = &rbuf[4]; rbuf[tftp_bufsize - 1] = '\0'; } else if (recv_blk < ARRAY_SIZE(errcode_str)) { @@ -533,14 +535,14 @@ static len_and_sockaddr *get_sock_lsa(int s) } int tftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; -int tftpd_main(int argc ATTRIBUTE_UNUSED, char **argv ATTRIBUTE_UNUSED) +int tftpd_main(int argc ATTRIBUTE_UNUSED, char **argv) { - struct stat statbuf; char block_buf[TFTP_BLOCKSIZE_DEFAULT]; len_and_sockaddr *our_lsa; len_and_sockaddr *peer_lsa; char *filename, *mode, *opt_str; - int result, opcode, cmd, req_modebits, open_mode, local_fd, blksize; + int opt_r, result, opcode, open_mode, local_fd, blksize; + USE_GETPUT(int cmd;) our_lsa = get_sock_lsa(STDIN_FILENO); if (!our_lsa) @@ -548,8 +550,10 @@ int tftpd_main(int argc ATTRIBUTE_UNUSED, char **argv ATTRIBUTE_UNUSED) peer_lsa = xzalloc(LSA_LEN_SIZE + our_lsa->len); peer_lsa->len = our_lsa->len; - if (argv[1]) - xchdir(argv[1]); + opt_r = getopt32(argv, "r"); + argv += optind; + if (argv[0]) + xchdir(argv[0]); result = recv_from_to(STDIN_FILENO, block_buf, sizeof(block_buf), 0 /* flags */, @@ -558,7 +562,10 @@ int tftpd_main(int argc ATTRIBUTE_UNUSED, char **argv ATTRIBUTE_UNUSED) opcode = ntohs(*(uint16_t*)block_buf); if (result < 4 || result >= sizeof(block_buf) || block_buf[result-1] != '\0' - || (opcode != TFTP_RRQ && opcode != TFTP_WRQ) + || (USE_FEATURE_TFTP_GET(opcode != TFTP_RRQ) /* not download */ + USE_GETPUT(&&) + USE_FEATURE_TFTP_GET(opcode != TFTP_WRQ) /* not upload */ + ) ) { bb_error_msg_and_die("malformed packet"); } @@ -584,21 +591,20 @@ int tftpd_main(int argc ATTRIBUTE_UNUSED, char **argv ATTRIBUTE_UNUSED) } } #endif - xstat(filename, &statbuf); - /* if opcode == TFTP_WRQ: */ - cmd = 1; /* CMD_GET: we will receive file's data */ - req_modebits = 0222; /* writable by anyone */ - open_mode = O_WRONLY | O_TRUNC; - if (opcode == TFTP_RRQ) { - cmd = 2; /* CMD_PUT */ - req_modebits = 0444; /* readable by anyone */ - open_mode = O_RDONLY; - } - if (!S_ISREG(statbuf.st_mode) - || (statbuf.st_mode & req_modebits) != req_modebits - ) { - bb_error_msg_and_die("access to '%s' is denied", filename); + +#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) + bb_error_msg_and_die("upload is prohibited"); + USE_GETPUT(cmd = 1;) /* CMD_GET: we will receive file's data */ + open_mode = O_WRONLY | O_TRUNC; } +#endif local_fd = xopen(filename, open_mode); close(STDIN_FILENO); /* close old, possibly wildcard socket */ |