diff options
| -rw-r--r-- | include/arpa/tftp.h | 2 | ||||
| -rw-r--r-- | libexec/tftpd/tftpd.c | 129 |
2 files changed, 122 insertions, 9 deletions
diff --git a/include/arpa/tftp.h b/include/arpa/tftp.h index 70a2029..84d7dc1 100644 --- a/include/arpa/tftp.h +++ b/include/arpa/tftp.h @@ -50,6 +50,7 @@ #define DATA 03 /* data packet */ #define ACK 04 /* acknowledgement */ #define ERROR 05 /* error code */ +#define OACK 06 /* option acknowledgement */ struct tftphdr { unsigned short th_opcode; /* packet type */ @@ -77,5 +78,6 @@ struct tftphdr { #define EBADID 5 /* unknown transfer ID */ #define EEXISTS 6 /* file already exists */ #define ENOUSER 7 /* no such user */ +#define EOPTNEG 8 /* option negotiation failed */ #endif /* !_TFTP_H_ */ diff --git a/libexec/tftpd/tftpd.c b/libexec/tftpd/tftpd.c index f219f08..8740fd1 100644 --- a/libexec/tftpd/tftpd.c +++ b/libexec/tftpd/tftpd.c @@ -79,10 +79,11 @@ static const char rcsid[] = #include "tftpsubs.h" #define TIMEOUT 5 +#define MAX_TIMEOUTS 5 int peer; int rexmtval = TIMEOUT; -int maxtimeout = 5*TIMEOUT; +int max_rexmtval = 2*TIMEOUT; #define PKTSIZE SEGSIZE+4 char buf[PKTSIZE]; @@ -110,6 +111,7 @@ static int ipchroot; static char *errtomsg __P((int)); static void nak __P((int)); +static void oack __P(()); int main(argc, argv) @@ -311,6 +313,21 @@ struct formats { { 0 } }; +struct options { + char *o_type; + char *o_request; + int o_reply; /* turn into union if need be */ +} options[] = { + { "tsize" }, /* OPT_TSIZE */ + { "timeout" }, /* OPT_TIMEOUT */ + { NULL } +}; + +enum opt_enum { + OPT_TSIZE = 0, + OPT_TIMEOUT, +}; + /* * Handle initial connection protocol. */ @@ -320,9 +337,9 @@ tftp(tp, size) int size; { register char *cp; - int first = 1, ecode; + int i, first = 1, has_options = 0, ecode; register struct formats *pf; - char *filename, *mode; + char *filename, *mode, *option, *ccp; filename = cp = tp->th_stuff; again: @@ -350,7 +367,40 @@ again: nak(EBADOP); exit(1); } + while (++cp < buf + size) { + for (i = 2, ccp = cp; i > 0; ccp++) { + if (ccp >= buf + size) { + nak(EBADOP); + exit(1); + } else if (*ccp == '\0') + i--; + } + for (option = cp; *cp; cp++) + if (isupper(*cp)) + *cp = tolower(*cp); + for (i = 0; options[i].o_type != NULL; i++) + if (strcmp(option, options[i].o_type) == 0) { + options[i].o_request = ++cp; + has_options = 1; + } + cp = ccp-1; + } + + if (options[OPT_TIMEOUT].o_request) { + int to = atoi(options[OPT_TIMEOUT].o_request); + if (to < 1 || to > 255) { + nak(EBADOP); + exit(1); + } + else if (to <= max_rexmtval) + options[OPT_TIMEOUT].o_reply = rexmtval = to; + else + options[OPT_TIMEOUT].o_request = NULL; + } + ecode = (*pf->f_validate)(&filename, tp->th_opcode); + if (has_options) + oack(); if (logging) { char host[MAXHOSTNAMELEN]; @@ -468,6 +518,14 @@ validate_access(filep, mode) return (err); *filep = filename = pathname; } + if (options[OPT_TSIZE].o_request) { + if (mode == RRQ) + options[OPT_TSIZE].o_reply = stbuf.st_size; + else + /* XXX Allows writes of all sizes. */ + options[OPT_TSIZE].o_reply = + atoi(options[OPT_TSIZE].o_request); + } fd = open(filename, mode == RRQ ? O_RDONLY : O_WRONLY|O_TRUNC); if (fd < 0) return (errno + 100); @@ -478,15 +536,13 @@ validate_access(filep, mode) return (0); } -int timeout; +int timeouts; jmp_buf timeoutbuf; void timer() { - - timeout += rexmtval; - if (timeout >= maxtimeout) + if (++timeouts > MAX_TIMEOUTS) exit(1); longjmp(timeoutbuf, 1); } @@ -515,7 +571,7 @@ xmitfile(pf) } dp->th_opcode = htons((u_short)DATA); dp->th_block = htons((u_short)block); - timeout = 0; + timeouts = 0; (void)setjmp(timeoutbuf); send_data: @@ -578,7 +634,7 @@ recvfile(pf) ap = (struct tftphdr *)ackbuf; block = 0; do { - timeout = 0; + timeouts = 0; ap->th_opcode = htons((u_short)ACK); ap->th_block = htons((u_short)block); block++; @@ -651,6 +707,7 @@ struct errmsg { { EBADID, "Unknown transfer ID" }, { EEXISTS, "File already exists" }, { ENOUSER, "No such user" }, + { EOPTNEG, "Option negotiation" }, { -1, 0 } }; @@ -700,3 +757,57 @@ nak(error) if (send(peer, buf, length, 0) != length) syslog(LOG_ERR, "nak: %m"); } + +/* + * Send an oack packet (option acknowledgement). + */ +static void +oack() +{ + struct tftphdr *tp, *ap; + int size, i, n; + char *bp; + + tp = (struct tftphdr *)buf; + bp = buf + 2; + size = sizeof(buf) - 2; + tp->th_opcode = htons((u_short)OACK); + for (i = 0; options[i].o_type != NULL; i++) { + if (options[i].o_request) { + n = snprintf(bp, size, "%s%c%d", options[i].o_type, + 0, options[i].o_reply); + bp += n+1; + size -= n+1; + if (size < 0) { + syslog(LOG_ERR, "oack: buffer overflow"); + exit(1); + } + } + } + size = bp - buf; + ap = (struct tftphdr *)ackbuf; + signal(SIGALRM, timer); + timeouts = 0; + + (void)setjmp(timeoutbuf); + if (send(peer, buf, size, 0) != size) { + syslog(LOG_INFO, "oack: %m"); + exit(1); + } + + for (;;) { + alarm(rexmtval); + n = recv(peer, ackbuf, sizeof (ackbuf), 0); + alarm(0); + if (n < 0) { + syslog(LOG_ERR, "recv: %m"); + exit(1); + } + ap->th_opcode = ntohs((u_short)ap->th_opcode); + ap->th_block = ntohs((u_short)ap->th_block); + if (ap->th_opcode == ERROR) + exit(1); + if (ap->th_opcode == ACK && ap->th_block == 0) + break; + } +} |
