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-rw-r--r--include/usage.h6
-rw-r--r--networking/tftp.c48
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 */