Apply Glenn's tftp rewrite
authorEric Andersen <andersen@codepoet.org>
Mon, 20 Aug 2001 17:47:49 +0000 (17:47 -0000)
committerEric Andersen <andersen@codepoet.org>
Mon, 20 Aug 2001 17:47:49 +0000 (17:47 -0000)
networking/tftp.c
tftp.c

index bb75c88..999b5d7 100644 (file)
 
 //#define BB_FEATURE_TFTP_DEBUG
 
-/* we don't need #ifdefs with these constants and optimization... */
-
-#ifdef BB_FEATURE_TFTP_GET
-#define BB_TFTP_GET (1 << 0)
-#else
-#define BB_TFTP_GET 0
-#endif
-
-#ifdef BB_FEATURE_TFTP_PUT
-#define BB_TFTP_PUT (1 << 1)
-#else
-#define BB_TFTP_PUT 0
-#endif
-
-#ifdef BB_FEATURE_TFTP_DEBUG
-#define BB_TFTP_DEBUG 1
-#else
-#define BB_TFTP_DEBUG 0
-#endif
-
-#define BB_TFTP_NO_RETRIES 5
-#define BB_TFTP_TIMEOUT    5   /* seconds */
-
-#define        RRQ     1                       /* read request */
-#define        WRQ     2                       /* write request */
-#define        DATA    3               /* data packet */
-#define        ACK     4                       /* acknowledgement */
-#define        ERROR   5               /* error code */
-
-#define BUFSIZE (512+4)
-
 static const char *tftp_error_msg[] = {
        "Undefined error",
        "File not found",
@@ -89,24 +58,32 @@ static const char *tftp_error_msg[] = {
        "No such user"
 };
 
-static inline int tftp(int cmd, struct hostent *host,
-                                          char *serverfile, int localfd, int port)
+const int tftp_cmd_get = 1;
+const int tftp_cmd_put = 2;
+
+static inline int tftp(const int cmd, const struct hostent *host,
+       const char *serverfile, int localfd, const int port, int tftp_bufsize)
 {
+       const int cmd_get = cmd & tftp_cmd_get;
+       const int cmd_put = cmd & tftp_cmd_put;
+       const int bb_tftp_num_retries = 5;
+
        struct sockaddr_in sa;
-       int socketfd;
-       struct timeval tv;
-       fd_set rfds;
        struct sockaddr_in from;
+       struct timeval tv;
        socklen_t fromlen;
+       fd_set rfds;
        char *cp;
        unsigned short tmp;
-       int len, opcode, finished;
-       int timeout, block_nr;
-
-       RESERVE_BB_BUFFER(buf, BUFSIZE);
+       int socketfd;
+       int len;
+       int opcode = 0;
+       int finished = 0;
+       int timeout = bb_tftp_num_retries;
+       int block_nr = 1;
+       RESERVE_BB_BUFFER(buf, tftp_bufsize + 4); // Why 4 ?
 
-       opcode = finished = timeout = 0;
-       block_nr = 1;
+       tftp_bufsize += 4;
 
        if ((socketfd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) {
                perror_msg("socket");
@@ -125,12 +102,12 @@ static inline int tftp(int cmd, struct hostent *host,
 
        /* build opcode */
 
-       if (cmd & BB_TFTP_GET) {
-               opcode = RRQ;
+       if (cmd_get) {
+               opcode = 1;     // read request = 1
        }
 
-       if (cmd & BB_TFTP_PUT) {
-               opcode = WRQ;
+       if (cmd_put) {
+               opcode = 2;     // write request = 2
        }
 
        while (1) {
@@ -147,16 +124,17 @@ static inline int tftp(int cmd, struct hostent *host,
 
                /* add filename and mode */
 
-               if ((BB_TFTP_GET && (opcode == RRQ)) ||
-                       (BB_TFTP_PUT && (opcode == WRQ))) {
+               if ((cmd_get && (opcode == 1)) || // read request = 1
+                       (cmd_put && (opcode == 2))) { // write request = 2
 
-                       while (cp != &buf[BUFSIZE - 1]) {
+                       /* what is this trying to do ? */
+                       while (cp != &buf[tftp_bufsize - 1]) {
                                if ((*cp = *serverfile++) == '\0')
                                        break;
                                cp++;
                        }
-
-                       if ((*cp != '\0') || (&buf[BUFSIZE - 1] - cp) < 7) {
+                       /* and this ? */
+                       if ((*cp != '\0') || (&buf[tftp_bufsize - 1] - cp) < 7) {
                                error_msg("too long server-filename");
                                break;
                        }
@@ -167,8 +145,8 @@ static inline int tftp(int cmd, struct hostent *host,
 
                /* add ack and data */
 
-               if ((BB_TFTP_GET && (opcode == ACK)) ||
-                       (BB_TFTP_PUT && (opcode == DATA))) {
+               if ((cmd_get && (opcode == 4)) || // acknowledgement = 4
+                       (cmd_put && (opcode == 3))) { // data packet == 3
 
                        *((unsigned short *) cp) = htons(block_nr);
 
@@ -176,15 +154,15 @@ static inline int tftp(int cmd, struct hostent *host,
 
                        block_nr++;
 
-                       if (BB_TFTP_PUT && (opcode == DATA)) {
-                               len = read(localfd, cp, BUFSIZE - 4);
+                       if (cmd_put && (opcode == 3)) { // data packet == 3
+                               len = read(localfd, cp, tftp_bufsize - 4);
 
                                if (len < 0) {
                                        perror_msg("read");
                                        break;
                                }
 
-                               if (len != (BUFSIZE - 4)) {
+                               if (len != (tftp_bufsize - 4)) {
                                        finished++;
                                }
 
@@ -202,16 +180,14 @@ static inline int tftp(int cmd, struct hostent *host,
 
                        len = cp - buf;
 
-                       if (BB_TFTP_DEBUG) {
-                               printf("sending %u bytes\n", len);
-
-                               for (cp = buf; cp < &buf[len]; cp++)
-                                       printf("%02x ", *cp);
-                               printf("\n");
-                       }
-
+#ifdef BB_FEATURE_TFTP_DEBUG
+                       printf("sending %u bytes\n", len);
+                       for (cp = buf; cp < &buf[len]; cp++)
+                               printf("%02x ", *cp);
+                       printf("\n");
+#endif
                        if (sendto(socketfd, buf, len, 0,
-                                          (struct sockaddr *) &sa, sizeof(sa)) < 0) {
+                                       (struct sockaddr *) &sa, sizeof(sa)) < 0) {
                                perror_msg("send");
                                len = -1;
                                break;
@@ -224,7 +200,7 @@ static inline int tftp(int cmd, struct hostent *host,
                        memset(&from, 0, sizeof(from));
                        fromlen = sizeof(from);
 
-                       tv.tv_sec = BB_TFTP_TIMEOUT;
+                       tv.tv_sec = 5; // BB_TFPT_TIMEOUT = 5
                        tv.tv_usec = 0;
 
                        FD_ZERO(&rfds);
@@ -232,9 +208,8 @@ static inline int tftp(int cmd, struct hostent *host,
 
                        switch (select(FD_SETSIZE, &rfds, NULL, NULL, &tv)) {
                        case 1:
-                               len = recvfrom(socketfd, buf,
-                                                          BUFSIZE, 0,
-                                                          (struct sockaddr *) &from, &fromlen);
+                               len = recvfrom(socketfd, buf, tftp_bufsize, 0,
+                                               (struct sockaddr *) &from, &fromlen);
 
                                if (len < 0) {
                                        perror_msg("recvfrom");
@@ -245,28 +220,23 @@ static inline int tftp(int cmd, struct hostent *host,
 
                                if (sa.sin_port == htons(port)) {
                                        sa.sin_port = from.sin_port;
-                                       break;
                                }
-
                                if (sa.sin_port == from.sin_port) {
                                        break;
                                }
 
                                /* fall-through for bad packets! */
                                /* discard the packet - treat as timeout */
+                               timeout = bb_tftp_num_retries;
 
                        case 0:
                                error_msg("timeout");
 
-                               if (!timeout) {
-                                       timeout = BB_TFTP_NO_RETRIES;
-                               } else {
-                                       timeout--;
-                               }
-
-                               if (!timeout) {
+                               if (timeout == 0) {
                                        len = -1;
                                        error_msg("last timeout");
+                               } else {
+                                       timeout--;
                                }
                                break;
 
@@ -287,11 +257,11 @@ static inline int tftp(int cmd, struct hostent *host,
                opcode = ntohs(*((unsigned short *) buf));
                tmp = ntohs(*((unsigned short *) &buf[2]));
 
-               if (BB_TFTP_DEBUG) {
-                       printf("received %d bytes: %04x %04x\n", len, opcode, tmp);
-               }
+#ifdef BB_FEATURE_TFTP_DEBUG
+               printf("received %d bytes: %04x %04x\n", len, opcode, tmp);
+#endif
 
-               if (BB_TFTP_GET && (opcode == DATA)) {
+               if (cmd_get && (opcode == 3)) { // data packet == 3
 
                        if (tmp == block_nr) {
                                len = write(localfd, &buf[4], len - 4);
@@ -301,33 +271,33 @@ static inline int tftp(int cmd, struct hostent *host,
                                        break;
                                }
 
-                               if (len != (BUFSIZE - 4)) {
+                               if (len != (tftp_bufsize - 4)) {
                                        finished++;
                                }
 
-                               opcode = ACK;
+                               opcode = 4; // acknowledgement = 4
                                continue;
                        }
                }
 
-               if (BB_TFTP_PUT && (opcode == ACK)) {
+               if (cmd_put && (opcode == 4)) { // acknowledgement = 4
 
                        if (tmp == (block_nr - 1)) {
                                if (finished) {
                                        break;
                                }
 
-                               opcode = DATA;
+                               opcode = 3; // data packet == 3
                                continue;
                        }
                }
 
-               if (opcode == ERROR) {
+               if (opcode == 5) { // error code == 5
                        char *msg = NULL;
 
                        if (buf[4] != '\0') {
                                msg = &buf[4];
-                               buf[BUFSIZE - 1] = '\0';
+                               buf[tftp_bufsize - 1] = '\0';
                        } else if (tmp < (sizeof(tftp_error_msg) / sizeof(char *))) {
                                msg = (char *) tftp_error_msg[tmp];
                        }
@@ -347,68 +317,67 @@ static inline int tftp(int cmd, struct hostent *host,
 
 int tftp_main(int argc, char **argv)
 {
-       char *cp, *s;
-       char *serverstr;
-       struct hostent *host;
-       char *serverfile;
-       char *localfile;
-       int cmd, flags, fd, bad;
-
-       host = (void *) serverstr = serverfile = localfile = NULL;
-       flags = cmd = 0;
-       bad = 1;
-
-       if (argc > 3) {
-               if (BB_TFTP_GET && (strcmp(argv[1], "get") == 0)) {
-                       cmd = BB_TFTP_GET;
+       struct hostent *host = NULL;
+       char *localfile = NULL;
+       char *remotefile = NULL;
+       int port = 69;
+       int cmd = 0;
+       int fd = -1;
+       int flags = 0;
+       int opt;
+       int result;
+       int blocksize = 512;
+
+       while ((opt = getopt(argc, argv, "b:gpl:r:")) != -1) {
+               switch (opt) {
+               case 'b':
+                       blocksize = atoi(optarg);
+                       break;
+#ifdef BB_FEATURE_TFTP_GET
+               case 'g':
+                       cmd = tftp_cmd_get;
                        flags = O_WRONLY | O_CREAT;
-                       serverstr = argv[2];
-                       localfile = argv[3];
-               }
-
-               if (BB_TFTP_PUT && (strcmp(argv[1], "put") == 0)) {
-                       cmd = BB_TFTP_PUT;
+                       break;
+#endif
+#ifdef BB_FEATURE_TFTP_PUT
+               case 'p':
+                       cmd = tftp_cmd_put;
                        flags = O_RDONLY;
-                       localfile = argv[2];
-                       serverstr = argv[3];
+                       break;
+#endif
+               case 'l': 
+                       localfile = xstrdup(optarg);
+                       break;
+               case 'r':
+                       remotefile = xstrdup(optarg);
+                       break;
                }
-
        }
 
-       if (!(cmd & (BB_TFTP_GET | BB_TFTP_PUT))) {
+       if ((cmd == 0) || (optind == argc)) {
                show_usage();
        }
 
-       for (cp = serverstr; *cp != '\0'; cp++)
-               if (*cp == ':')
-                       break;
-
-       if (*cp == ':') {
-
-               serverfile = cp + 1;
-
-               s = xstrdup(serverstr);
-               s[cp - serverstr] = '\0';
-
-               host = xgethostbyname(s);
-
-               free(s);
+       fd = open(localfile, flags, 0644);
+       if (fd < 0) {
+               perror_msg_and_die("local file");
        }
 
-       if (BB_TFTP_DEBUG) {
-               printf("using server \"%s\", serverfile \"%s\","
-                          "localfile \"%s\".\n",
-                          inet_ntoa(*((struct in_addr *) host->h_addr)),
-                          serverfile, localfile);
-       }
+       host = xgethostbyname(argv[optind]);
 
-       if ((fd = open(localfile, flags, 0644)) < 0) {
-               perror_msg_and_die("local file");
+       if (optind + 2 == argc) {
+               port = atoi(argv[optind + 1]);
        }
 
-       flags = tftp(cmd, host, serverfile, fd, 69);
+#ifdef BB_FEATURE_TFTP_DEBUG
+       printf("using server \"%s\", serverfile \"%s\","
+               "localfile \"%s\".\n",
+               inet_ntoa(*((struct in_addr *) host->h_addr)),
+               remotefile, localfile);
+#endif
 
+       result = tftp(cmd, host, remotefile, fd, port, blocksize);
        close(fd);
 
-       return flags;
-}
+       return(result);
+}
\ No newline at end of file
diff --git a/tftp.c b/tftp.c
index bb75c88..999b5d7 100644 (file)
--- a/tftp.c
+++ b/tftp.c
 
 //#define BB_FEATURE_TFTP_DEBUG
 
-/* we don't need #ifdefs with these constants and optimization... */
-
-#ifdef BB_FEATURE_TFTP_GET
-#define BB_TFTP_GET (1 << 0)
-#else
-#define BB_TFTP_GET 0
-#endif
-
-#ifdef BB_FEATURE_TFTP_PUT
-#define BB_TFTP_PUT (1 << 1)
-#else
-#define BB_TFTP_PUT 0
-#endif
-
-#ifdef BB_FEATURE_TFTP_DEBUG
-#define BB_TFTP_DEBUG 1
-#else
-#define BB_TFTP_DEBUG 0
-#endif
-
-#define BB_TFTP_NO_RETRIES 5
-#define BB_TFTP_TIMEOUT    5   /* seconds */
-
-#define        RRQ     1                       /* read request */
-#define        WRQ     2                       /* write request */
-#define        DATA    3               /* data packet */
-#define        ACK     4                       /* acknowledgement */
-#define        ERROR   5               /* error code */
-
-#define BUFSIZE (512+4)
-
 static const char *tftp_error_msg[] = {
        "Undefined error",
        "File not found",
@@ -89,24 +58,32 @@ static const char *tftp_error_msg[] = {
        "No such user"
 };
 
-static inline int tftp(int cmd, struct hostent *host,
-                                          char *serverfile, int localfd, int port)
+const int tftp_cmd_get = 1;
+const int tftp_cmd_put = 2;
+
+static inline int tftp(const int cmd, const struct hostent *host,
+       const char *serverfile, int localfd, const int port, int tftp_bufsize)
 {
+       const int cmd_get = cmd & tftp_cmd_get;
+       const int cmd_put = cmd & tftp_cmd_put;
+       const int bb_tftp_num_retries = 5;
+
        struct sockaddr_in sa;
-       int socketfd;
-       struct timeval tv;
-       fd_set rfds;
        struct sockaddr_in from;
+       struct timeval tv;
        socklen_t fromlen;
+       fd_set rfds;
        char *cp;
        unsigned short tmp;
-       int len, opcode, finished;
-       int timeout, block_nr;
-
-       RESERVE_BB_BUFFER(buf, BUFSIZE);
+       int socketfd;
+       int len;
+       int opcode = 0;
+       int finished = 0;
+       int timeout = bb_tftp_num_retries;
+       int block_nr = 1;
+       RESERVE_BB_BUFFER(buf, tftp_bufsize + 4); // Why 4 ?
 
-       opcode = finished = timeout = 0;
-       block_nr = 1;
+       tftp_bufsize += 4;
 
        if ((socketfd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) {
                perror_msg("socket");
@@ -125,12 +102,12 @@ static inline int tftp(int cmd, struct hostent *host,
 
        /* build opcode */
 
-       if (cmd & BB_TFTP_GET) {
-               opcode = RRQ;
+       if (cmd_get) {
+               opcode = 1;     // read request = 1
        }
 
-       if (cmd & BB_TFTP_PUT) {
-               opcode = WRQ;
+       if (cmd_put) {
+               opcode = 2;     // write request = 2
        }
 
        while (1) {
@@ -147,16 +124,17 @@ static inline int tftp(int cmd, struct hostent *host,
 
                /* add filename and mode */
 
-               if ((BB_TFTP_GET && (opcode == RRQ)) ||
-                       (BB_TFTP_PUT && (opcode == WRQ))) {
+               if ((cmd_get && (opcode == 1)) || // read request = 1
+                       (cmd_put && (opcode == 2))) { // write request = 2
 
-                       while (cp != &buf[BUFSIZE - 1]) {
+                       /* what is this trying to do ? */
+                       while (cp != &buf[tftp_bufsize - 1]) {
                                if ((*cp = *serverfile++) == '\0')
                                        break;
                                cp++;
                        }
-
-                       if ((*cp != '\0') || (&buf[BUFSIZE - 1] - cp) < 7) {
+                       /* and this ? */
+                       if ((*cp != '\0') || (&buf[tftp_bufsize - 1] - cp) < 7) {
                                error_msg("too long server-filename");
                                break;
                        }
@@ -167,8 +145,8 @@ static inline int tftp(int cmd, struct hostent *host,
 
                /* add ack and data */
 
-               if ((BB_TFTP_GET && (opcode == ACK)) ||
-                       (BB_TFTP_PUT && (opcode == DATA))) {
+               if ((cmd_get && (opcode == 4)) || // acknowledgement = 4
+                       (cmd_put && (opcode == 3))) { // data packet == 3
 
                        *((unsigned short *) cp) = htons(block_nr);
 
@@ -176,15 +154,15 @@ static inline int tftp(int cmd, struct hostent *host,
 
                        block_nr++;
 
-                       if (BB_TFTP_PUT && (opcode == DATA)) {
-                               len = read(localfd, cp, BUFSIZE - 4);
+                       if (cmd_put && (opcode == 3)) { // data packet == 3
+                               len = read(localfd, cp, tftp_bufsize - 4);
 
                                if (len < 0) {
                                        perror_msg("read");
                                        break;
                                }
 
-                               if (len != (BUFSIZE - 4)) {
+                               if (len != (tftp_bufsize - 4)) {
                                        finished++;
                                }
 
@@ -202,16 +180,14 @@ static inline int tftp(int cmd, struct hostent *host,
 
                        len = cp - buf;
 
-                       if (BB_TFTP_DEBUG) {
-                               printf("sending %u bytes\n", len);
-
-                               for (cp = buf; cp < &buf[len]; cp++)
-                                       printf("%02x ", *cp);
-                               printf("\n");
-                       }
-
+#ifdef BB_FEATURE_TFTP_DEBUG
+                       printf("sending %u bytes\n", len);
+                       for (cp = buf; cp < &buf[len]; cp++)
+                               printf("%02x ", *cp);
+                       printf("\n");
+#endif
                        if (sendto(socketfd, buf, len, 0,
-                                          (struct sockaddr *) &sa, sizeof(sa)) < 0) {
+                                       (struct sockaddr *) &sa, sizeof(sa)) < 0) {
                                perror_msg("send");
                                len = -1;
                                break;
@@ -224,7 +200,7 @@ static inline int tftp(int cmd, struct hostent *host,
                        memset(&from, 0, sizeof(from));
                        fromlen = sizeof(from);
 
-                       tv.tv_sec = BB_TFTP_TIMEOUT;
+                       tv.tv_sec = 5; // BB_TFPT_TIMEOUT = 5
                        tv.tv_usec = 0;
 
                        FD_ZERO(&rfds);
@@ -232,9 +208,8 @@ static inline int tftp(int cmd, struct hostent *host,
 
                        switch (select(FD_SETSIZE, &rfds, NULL, NULL, &tv)) {
                        case 1:
-                               len = recvfrom(socketfd, buf,
-                                                          BUFSIZE, 0,
-                                                          (struct sockaddr *) &from, &fromlen);
+                               len = recvfrom(socketfd, buf, tftp_bufsize, 0,
+                                               (struct sockaddr *) &from, &fromlen);
 
                                if (len < 0) {
                                        perror_msg("recvfrom");
@@ -245,28 +220,23 @@ static inline int tftp(int cmd, struct hostent *host,
 
                                if (sa.sin_port == htons(port)) {
                                        sa.sin_port = from.sin_port;
-                                       break;
                                }
-
                                if (sa.sin_port == from.sin_port) {
                                        break;
                                }
 
                                /* fall-through for bad packets! */
                                /* discard the packet - treat as timeout */
+                               timeout = bb_tftp_num_retries;
 
                        case 0:
                                error_msg("timeout");
 
-                               if (!timeout) {
-                                       timeout = BB_TFTP_NO_RETRIES;
-                               } else {
-                                       timeout--;
-                               }
-
-                               if (!timeout) {
+                               if (timeout == 0) {
                                        len = -1;
                                        error_msg("last timeout");
+                               } else {
+                                       timeout--;
                                }
                                break;
 
@@ -287,11 +257,11 @@ static inline int tftp(int cmd, struct hostent *host,
                opcode = ntohs(*((unsigned short *) buf));
                tmp = ntohs(*((unsigned short *) &buf[2]));
 
-               if (BB_TFTP_DEBUG) {
-                       printf("received %d bytes: %04x %04x\n", len, opcode, tmp);
-               }
+#ifdef BB_FEATURE_TFTP_DEBUG
+               printf("received %d bytes: %04x %04x\n", len, opcode, tmp);
+#endif
 
-               if (BB_TFTP_GET && (opcode == DATA)) {
+               if (cmd_get && (opcode == 3)) { // data packet == 3
 
                        if (tmp == block_nr) {
                                len = write(localfd, &buf[4], len - 4);
@@ -301,33 +271,33 @@ static inline int tftp(int cmd, struct hostent *host,
                                        break;
                                }
 
-                               if (len != (BUFSIZE - 4)) {
+                               if (len != (tftp_bufsize - 4)) {
                                        finished++;
                                }
 
-                               opcode = ACK;
+                               opcode = 4; // acknowledgement = 4
                                continue;
                        }
                }
 
-               if (BB_TFTP_PUT && (opcode == ACK)) {
+               if (cmd_put && (opcode == 4)) { // acknowledgement = 4
 
                        if (tmp == (block_nr - 1)) {
                                if (finished) {
                                        break;
                                }
 
-                               opcode = DATA;
+                               opcode = 3; // data packet == 3
                                continue;
                        }
                }
 
-               if (opcode == ERROR) {
+               if (opcode == 5) { // error code == 5
                        char *msg = NULL;
 
                        if (buf[4] != '\0') {
                                msg = &buf[4];
-                               buf[BUFSIZE - 1] = '\0';
+                               buf[tftp_bufsize - 1] = '\0';
                        } else if (tmp < (sizeof(tftp_error_msg) / sizeof(char *))) {
                                msg = (char *) tftp_error_msg[tmp];
                        }
@@ -347,68 +317,67 @@ static inline int tftp(int cmd, struct hostent *host,
 
 int tftp_main(int argc, char **argv)
 {
-       char *cp, *s;
-       char *serverstr;
-       struct hostent *host;
-       char *serverfile;
-       char *localfile;
-       int cmd, flags, fd, bad;
-
-       host = (void *) serverstr = serverfile = localfile = NULL;
-       flags = cmd = 0;
-       bad = 1;
-
-       if (argc > 3) {
-               if (BB_TFTP_GET && (strcmp(argv[1], "get") == 0)) {
-                       cmd = BB_TFTP_GET;
+       struct hostent *host = NULL;
+       char *localfile = NULL;
+       char *remotefile = NULL;
+       int port = 69;
+       int cmd = 0;
+       int fd = -1;
+       int flags = 0;
+       int opt;
+       int result;
+       int blocksize = 512;
+
+       while ((opt = getopt(argc, argv, "b:gpl:r:")) != -1) {
+               switch (opt) {
+               case 'b':
+                       blocksize = atoi(optarg);
+                       break;
+#ifdef BB_FEATURE_TFTP_GET
+               case 'g':
+                       cmd = tftp_cmd_get;
                        flags = O_WRONLY | O_CREAT;
-                       serverstr = argv[2];
-                       localfile = argv[3];
-               }
-
-               if (BB_TFTP_PUT && (strcmp(argv[1], "put") == 0)) {
-                       cmd = BB_TFTP_PUT;
+                       break;
+#endif
+#ifdef BB_FEATURE_TFTP_PUT
+               case 'p':
+                       cmd = tftp_cmd_put;
                        flags = O_RDONLY;
-                       localfile = argv[2];
-                       serverstr = argv[3];
+                       break;
+#endif
+               case 'l': 
+                       localfile = xstrdup(optarg);
+                       break;
+               case 'r':
+                       remotefile = xstrdup(optarg);
+                       break;
                }
-
        }
 
-       if (!(cmd & (BB_TFTP_GET | BB_TFTP_PUT))) {
+       if ((cmd == 0) || (optind == argc)) {
                show_usage();
        }
 
-       for (cp = serverstr; *cp != '\0'; cp++)
-               if (*cp == ':')
-                       break;
-
-       if (*cp == ':') {
-
-               serverfile = cp + 1;
-
-               s = xstrdup(serverstr);
-               s[cp - serverstr] = '\0';
-
-               host = xgethostbyname(s);
-
-               free(s);
+       fd = open(localfile, flags, 0644);
+       if (fd < 0) {
+               perror_msg_and_die("local file");
        }
 
-       if (BB_TFTP_DEBUG) {
-               printf("using server \"%s\", serverfile \"%s\","
-                          "localfile \"%s\".\n",
-                          inet_ntoa(*((struct in_addr *) host->h_addr)),
-                          serverfile, localfile);
-       }
+       host = xgethostbyname(argv[optind]);
 
-       if ((fd = open(localfile, flags, 0644)) < 0) {
-               perror_msg_and_die("local file");
+       if (optind + 2 == argc) {
+               port = atoi(argv[optind + 1]);
        }
 
-       flags = tftp(cmd, host, serverfile, fd, 69);
+#ifdef BB_FEATURE_TFTP_DEBUG
+       printf("using server \"%s\", serverfile \"%s\","
+               "localfile \"%s\".\n",
+               inet_ntoa(*((struct in_addr *) host->h_addr)),
+               remotefile, localfile);
+#endif
 
+       result = tftp(cmd, host, remotefile, fd, port, blocksize);
        close(fd);
 
-       return flags;
-}
+       return(result);
+}
\ No newline at end of file