1 /* utftpd_recv.c: the server side receiving routine */ 2 3 /* 4 * Copyright (C) 1999 Uwe Ohse 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 19 */ 20 21 #include "config.h" 22 #include <sys/types.h> 23 #include <sys/ioctl.h> 24 #include <sys/stat.h> 25 #include <fcntl.h> 26 27 #include <sys/socket.h> 28 #include <netinet/in.h> 29 #include "no_tftp.h" 30 31 #include <syslog.h> 32 #include <errno.h> 33 #include <unistd.h> 34 #include <string.h> 35 #include <signal.h> 36 #include "timselsysdep.h" 37 #include "str2num.h" 38 #include "uostr.h" 39 #include "uoio.h" 40 #include "utftpd.h" 41 42 #define ERR_LOG1(x) do { const char *er=strerror(errno); syslog(LOG_ERR,x,er); } while(0) 43 #define ERR_LOG2(x,y) do { const char *er=strerror(errno); syslog(LOG_ERR,x,y,er); } while(0) 44 45 static int got_sig; 46 static void 47 sig_handler(int signo) 48 { 49 got_sig=signo; 50 } 51 52 /* 53 * well, this is everything but beautiful. To be able to resend a lost packet we 54 * have to send the first ACK/OACK here. But since that contains data we should not 55 * now about ... 56 * i absolutely don't care about any cleanup actions here: we exit after we received 57 * that file. 58 */ 59 int 60 utftpd_recv(struct utftpd_ctrl *flags) 61 { 62 uoio_t io; 63 int blockno; 64 int lastchar=-1; /* in case of netascii */ 65 int netascii=flags->netascii; 66 ssize_t got; 67 int got_timeouts=0; 68 struct sigaction sa; 69 struct sigaction old_sa; 70 const char *errortext; 71 size_t sendlength; 72 unsigned short got_blockno; 73 short got_opcode; 74 int is_final=0; 75 76 sa.sa_handler = sig_handler; 77 sa.sa_flags = 0; 78 sigemptyset (&sa.sa_mask); 79 sigaction (SIGALRM, &sa, &old_sa); 80 81 uoio_assign_w(&io,flags->filefd,write,0); 82 83 blockno=1; 84 got=flags->segsize+TFTP_OFFSET; 85 flags->sendbuf.hdr->th_block = htons(0); 86 sendlength=flags->first_packet_length+TFTP_OFFSET; 87 88 while (1) { 89 /* send the ACK / OACK */ 90 while (1) { 91 if (send(flags->remotefd, flags->sendbuf.buf, sendlength, 0) != (ssize_t) sendlength) 92 { ERR_LOG1("send: %s"); goto do_error; } 93 94 /* read data */ 95 alarm( (flags->timeout ? flags->timeout : 5) 96 * (got_timeouts+1)); 97 got = recv(flags->remotefd, flags->recvbuf.buf, flags->segsize+TFTP_OFFSET, 0); 98 if (got < 0) { 99 if (errno==EINTR && got_sig==SIGALRM && got_timeouts++<5) continue; /* resend my ACK */ 100 ERR_LOG1("recv: %s"); 101 goto do_error; 102 } 103 got_timeouts=0; /* we got a packet */ 104 got_opcode = ntohs((u_short)flags->recvbuf.hdr->th_opcode); 105 got_blockno = ntohs((u_short)flags->recvbuf.hdr->th_block); 106 if (got_opcode == ERROR) { 107 if (got>5) { 108 if (flags->recvbuf.buf[got-1]!=0) { 109 syslog(LOG_ERR,"got ERROR opcode with unterminated error text, last character removed:"); 110 flags->recvbuf.buf[got-1]=0; 111 } 112 syslog(LOG_ERR,"%s",flags->recvbuf.buf+TFTP_OFFSET); 113 goto do_error; 114 } else { 115 syslog(LOG_ERR,"got ERROR opcode, no error text"); 116 goto do_error; 117 } 118 } 119 if (got_opcode != DATA) { 120 syslog(LOG_ERR, "got unknown opcode %d",flags->recvbuf.hdr->th_opcode); 121 errortext="got unknown TFTP opcode"; 122 goto do_error_nak; 123 } 124 if (got_blockno == blockno) break; 125 /* out of sync. Throw away everything the kernel may have buffered */ 126 while (1) { 127 struct timeval tv; 128 fd_set set; 129 FD_SET(flags->remotefd,&set); 130 tv.tv_sec=0; 131 tv.tv_usec=0; 132 if (select(flags->remotefd+1,&set,0,0,&tv)<1) 133 break; 134 alarm(flags->timeout ? flags->timeout : 5); 135 (void) recv(flags->remotefd, flags->recvbuf.buf, flags->segsize +TFTP_OFFSET, 0); 136 } 137 /* go back to resend ACK */ 138 } 139 /* ok, got something */ 140 if (netascii) { 141 char *p,*q,*end; 142 p=q=flags->recvbuf.buf+TFTP_OFFSET; 143 end=flags->recvbuf.buf+got; 144 while (p!=end) { 145 if (lastchar=='\r') { 146 if (*p==0) { 147 *q++='\r'; 148 p++; 149 } else 150 *q++=*p++; 151 lastchar=-1; 152 } else { 153 lastchar=*p; 154 if (*p=='\r') 155 p++; 156 else 157 *q++=*p++; 158 } 159 } 160 uoio_write_mem(&io,flags->recvbuf.buf+TFTP_OFFSET,q-(flags->recvbuf.buf+TFTP_OFFSET)); 161 flags->bytes+=q-(flags->recvbuf.buf+TFTP_OFFSET); 162 } else { 163 uoio_write_mem(&io,flags->recvbuf.buf+TFTP_OFFSET,got-TFTP_OFFSET); 164 flags->bytes+=got-TFTP_OFFSET; 165 } 166 if (got!=(ssize_t) flags->segsize+TFTP_OFFSET) { 167 uoio_flush(&io); 168 uoio_destroy(&io); 169 #if 0 170 #ifdef HAVE_FSYNC 171 if (-1==fsync(flags->filefd)) { errortext=strerror(errno); ERR_LOG2("fsync(%s): %s", flags->filename); goto do_error_nak; } 172 #else 173 sync(); 174 #endif 175 if (-1==close(flags->filefd)) { errortext=strerror(errno); ERR_LOG2("close(%s): %s", flags->filename); goto do_error_nak; } 176 #endif 177 is_final=1; 178 } 179 flags->sendbuf.hdr->th_opcode = htons((u_short)ACK); 180 flags->sendbuf.hdr->th_block = htons((u_short)blockno++); 181 sendlength=TFTP_OFFSET; 182 if (is_final) break; /* final ACK is sent from above, after version control */ 183 } /* while 1 */ 184 alarm(0); 185 sigaction (SIGALRM, &old_sa,0 ); 186 return 0; 187 do_error_nak: 188 alarm(0); 189 sigaction (SIGALRM, &old_sa,0 ); 190 utftpd_nak(flags->remotefd,EUNDEF,errortext,flags); 191 return -1; 192 do_error: 193 alarm(0); 194 sigaction (SIGALRM, &old_sa,0 ); 195 return -1; 196 } 197