tftp: optional tftp-hpa compat

function                                             old     new   delta
tftp_main                                            276     394    +118

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

2 files changed, 43 insertions, 3 deletions

diff --git a/libbb/xconnect.c b/libbb/xconnect.c
index ea5fe173f..eb2871cb1 100644
--- a/libbb/xconnect.c
+++ b/libbb/xconnect.c
@@ -133,6 +133,7 @@ unsigned FAST_FUNC bb_lookup_port(const char *port, const char *protocol, unsign
                         port_nr = default_port;
                         if (tserv)
                                 port_nr = ntohs(tserv->s_port);
+//FIXME: else: port string was garbage, but we don't report that???
                 }
                 errno = old_errno;
         }
diff --git a/networking/tftp.c b/networking/tftp.c
index 5ebd22105..30232ef8e 100644
--- a/networking/tftp.c
+++ b/networking/tftp.c
@@ -31,6 +31,11 @@
 //config:       default y
 //config:       depends on TFTP
 //config:
+//config:config FEATURE_TFTP_HPA_COMPAT
+//config:       bool "tftp-hpa compat (support -c get/put FILE)"
+//config:       default y
+//config:       depends on TFTP
+//config:
 //config:config TFTPD
 //config:       bool "tftpd (10 kb)"
 //config:       default y
@@ -101,9 +106,10 @@
 //usage:        IF_FEATURE_TFTP_BLOCKSIZE(
 //usage:     "\n        -b SIZE Transfer blocks of SIZE octets"
 //usage:        )
+///////:     "\n        -m STR  Accepted and ignored ('-m binary' compat with tftp-hpa 5.2)"
 //usage:
 //usage:#define tftpd_trivial_usage
-//usage:       "[-cr] [-u USER] [DIR]"
+//usage:       "[-crl] [-u USER] [DIR]"
 //usage:#define tftpd_full_usage "\n\n"
 //usage:       "Transfer a file on tftp client's request\n"
 //usage:       "\n"
@@ -759,15 +765,46 @@ int tftp_main(int argc UNUSED_PARAM, char **argv)
 
         INIT_G();
 
+        if (ENABLE_FEATURE_TFTP_HPA_COMPAT) {
+                /* As of 2019, common tftp client in Linux distros
+                 * is one maintained by H. Peter Anvin:
+                 * I've seen "tftp-hpa 5.2" version.
+                 * Make the following command work:
+                 *  "tftp HOST [PORT] -m binary -c get/put FILE"
+                 * by mangling it into "....... -g/-p -r FILE"
+                 * and accepting and ignoring -m STR option.
+                 */
+                unsigned i = 1;
+                while (argv[i]) {
+                        if (strcmp(argv[i], "-c") == 0) {
+                                if (!argv[++i])
+                                        break;
+                                if (strcmp(argv[i], "get") == 0) {
+                                        argv[i-1] = (char*)"-g";
+                                        argv[i] = (char*)"-r";
+                                        break;
+                                }
+                                if (strcmp(argv[i], "put") == 0) {
+                                        argv[i-1] = (char*)"-p";
+                                        argv[i] = (char*)"-r";
+                                        break;
+                                }
+                        }
+                        i++;
+                }
+        }
+
         IF_GETPUT(opt =) getopt32(argv, "^"
                         IF_FEATURE_TFTP_GET("g") IF_FEATURE_TFTP_PUT("p")
                         "l:r:" IF_FEATURE_TFTP_BLOCKSIZE("b:")
+                        IF_FEATURE_TFTP_HPA_COMPAT("m:")
                         "\0"
                         /* -p or -g is mandatory, and they are mutually exclusive */
                         IF_FEATURE_TFTP_GET("g:") IF_FEATURE_TFTP_PUT("p:")
                         IF_GETPUT("g--p:p--g:"),
                         &local_file, &remote_file
                         IF_FEATURE_TFTP_BLOCKSIZE(, &blksize_str)
+                        IF_FEATURE_TFTP_HPA_COMPAT(, NULL)
         );
         argv += optind;
 
@@ -851,7 +888,7 @@ int tftpd_main(int argc UNUSED_PARAM, char **argv)
         peer_lsa->len = our_lsa->len;
 
         /* Shifting to not collide with TFTP_OPTs */
-        opt = option_mask32 = TFTPD_OPT | (getopt32(argv, "rcu:l", &user_opt) << 8);
+        opt = option_mask32 = TFTPD_OPT | (getopt32(argv, "rcu:lm:", &user_opt, NULL) << 8);
         argv += optind;
         if (opt & TFTPD_OPT_l) {
                 openlog(applet_name, LOG_PID, LOG_DAEMON);
@@ -897,6 +934,7 @@ int tftpd_main(int argc UNUSED_PARAM, char **argv)
         mode = local_file + strlen(local_file) + 1;
         /* RFC 1350 says mode string is case independent */
         if (mode >= G.block_buf + result || strcasecmp(mode, "octet") != 0) {
+                error_msg = "mode is not 'octet'";
                 goto err;
         }
 # if ENABLE_FEATURE_TFTP_BLOCKSIZE
@@ -944,7 +982,8 @@ int tftpd_main(int argc UNUSED_PARAM, char **argv)
         /* tftp_protocol() will create new one, bound to particular local IP */
         result = tftp_protocol(
                 our_lsa, peer_lsa,
-                local_file IF_TFTP(, NULL /*remote_file*/)
+                local_file
+                IF_TFTP(, NULL /*remote_file*/)
                 IF_FEATURE_TFTP_BLOCKSIZE(, want_transfer_size)
                 IF_FEATURE_TFTP_BLOCKSIZE(, blksize)
         );