void ttymodes_unpackw (char const *s, ttymodes_ref t)
{
uint16 u ;
uint16_unpack(s, &u) ;
t->ws.ws_row = u ;
s += 2 ;
uint16_unpack(s, &u) ;
t->ws.ws_col = u ;
s += 2 ;
uint16_unpack(s, &u) ;
t->ws.ws_xpixel = u ;
s += 2 ;
uint16_unpack(s, &u) ;
t->ws.ws_ypixel = u ;
}
int main(int argc,char **argv)
{
long long pos;
long long len;
long long u;
long long r;
long long i;
long long k;
long long recent;
long long nextaction;
long long timeout;
struct pollfd *q;
struct pollfd *watch8;
struct pollfd *watchtochild;
struct pollfd *watchfromchild;
signal(SIGPIPE,SIG_IGN);
if (!argv[0]) die_usage(0);
for (;;) {
char *x;
if (!argv[1]) break;
if (argv[1][0] != '-') break;
x = *++argv;
if (x[0] == '-' && x[1] == 0) break;
if (x[0] == '-' && x[1] == '-' && x[2] == 0) break;
while (*++x) {
if (*x == 'q') { flagverbose = 0; continue; }
if (*x == 'Q') { flagverbose = 1; continue; }
if (*x == 'v') { if (flagverbose == 2) flagverbose = 3; else flagverbose = 2; continue; }
if (*x == 'c') { flagserver = 0; wantping = 2; continue; }
if (*x == 'C') { flagserver = 0; wantping = 1; continue; }
if (*x == 's') { flagserver = 1; wantping = 0; continue; }
die_usage(0);
}
}
if (!*++argv) die_usage("missing prog");
for (;;) {
r = open_read("/dev/null");
if (r == -1) die_fatal("unable to open /dev/null",0,0);
if (r > 9) { close(r); break; }
}
if (open_pipe(tochild) == -1) die_fatal("unable to create pipe",0,0);
if (open_pipe(fromchild) == -1) die_fatal("unable to create pipe",0,0);
blocking_enable(tochild[0]);
blocking_enable(fromchild[1]);
child = fork();
if (child == -1) die_fatal("unable to fork",0,0);
if (child == 0) {
close(8);
close(9);
if (flagserver) {
close(0);
if (dup(tochild[0]) != 0) die_fatal("unable to dup",0,0);
close(1);
if (dup(fromchild[1]) != 1) die_fatal("unable to dup",0,0);
} else {
close(6);
if (dup(tochild[0]) != 6) die_fatal("unable to dup",0,0);
close(7);
if (dup(fromchild[1]) != 7) die_fatal("unable to dup",0,0);
}
signal(SIGPIPE,SIG_DFL);
execvp(*argv,argv);
die_fatal("unable to run",*argv,0);
}
close(tochild[0]);
close(fromchild[1]);
recent = nanoseconds();
lastspeedadjustment = recent;
if (flagserver) maxblocklen = 1024;
for (;;) {
if (sendeofacked)
if (receivewritten == receivetotalbytes)
if (receiveeof)
if (tochild[1] < 0)
break; /* XXX: to re-ack should enter a TIME-WAIT state here */
q = p;
watch8 = q;
if (watch8) { q->fd = 8; q->events = POLLIN; ++q; }
watchtochild = q;
if (tochild[1] < 0) watchtochild = 0;
if (receivewritten >= receivebytes) watchtochild = 0;
if (watchtochild) { q->fd = tochild[1]; q->events = POLLOUT; ++q; }
watchfromchild = q;
if (sendeof) watchfromchild = 0;
if (sendbytes + 4096 > sizeof sendbuf) watchfromchild = 0;
if (watchfromchild) { q->fd = fromchild[0]; q->events = POLLIN; ++q; }
nextaction = recent + 60000000000LL;
if (wantping == 1) nextaction = recent + 1000000000;
if (wantping == 2) nextaction = 0;
if (blocknum < OUTGOING)
if (!(sendeof ? sendeofprocessed : sendprocessed >= sendbytes))
if (nextaction > lastblocktime + nsecperblock) nextaction = lastblocktime + nsecperblock;
if (earliestblocktime) {
long long nextretry = earliestblocktime + rtt_timeout;
if (nextretry < lastblocktime + nsecperblock) nextretry = lastblocktime + nsecperblock;
if (nextretry < nextaction) nextaction = nextretry;
}
if (messagenum)
if (!watchtochild)
nextaction = 0;
if (nextaction <= recent)
timeout = 0;
else
timeout = (nextaction - recent) / 1000000 + 1;
/* XXX */
if (childdied) timeout = 10;
pollret = poll(p,q - p,timeout);
if (pollret < 0) {
watch8 = 0;
watchtochild = 0;
watchfromchild = 0;
} else {
if (watch8) if (!watch8->revents) watch8 = 0;
if (watchtochild) if (!watchtochild->revents) watchtochild = 0;
if (watchfromchild) if (!watchfromchild->revents) watchfromchild = 0;
}
/* XXX */
if (childdied && !pollret) {
if (childdied++ > 999) goto finish;
}
/* XXX: keepalives */
do { /* try receiving data from child: */
if (!watchfromchild) break;
if (sendeof) break;
if (sendbytes + 4096 > sizeof sendbuf) break;
pos = (sendacked & (sizeof sendbuf - 1)) + sendbytes;
if (pos < sizeof sendbuf) {
r = read(fromchild[0],sendbuf + pos,sizeof sendbuf - pos);
} else {
r = read(fromchild[0],sendbuf + pos - sizeof sendbuf,sizeof sendbuf - sendbytes);
}
if (r == -1) if (errno == EINTR || errno == EWOULDBLOCK || errno == EAGAIN) break;
if (r < 0) { sendeof = 4096; break; }
if (r == 0) { sendeof = 2048; break; }
sendbytes += r;
if (sendbytes >= 1152921504606846976LL) die_internalerror();
} while(0);
recent = nanoseconds();
do { /* try re-sending an old block: */
if (recent < lastblocktime + nsecperblock) break;
if (earliestblocktime == 0) break;
if (recent < earliestblocktime + rtt_timeout) break;
for (i = 0;i < blocknum;++i) {
pos = (blockfirst + i) & (OUTGOING - 1);
if (blocktime[pos] == earliestblocktime) {
if (recent > lastpanic + 4 * rtt_timeout) {
nsecperblock *= 2;
lastpanic = recent;
lastedge = recent;
}
goto sendblock;
}
}
} while(0);
do { /* try sending a new block: */
if (recent < lastblocktime + nsecperblock) break;
if (blocknum >= OUTGOING) break;
if (!wantping)
if (sendeof ? sendeofprocessed : sendprocessed >= sendbytes) break;
/* XXX: if any Nagle-type processing is desired, do it here */
pos = (blockfirst + blocknum) & (OUTGOING - 1);
++blocknum;
blockpos[pos] = sendacked + sendprocessed;
blocklen[pos] = sendbytes - sendprocessed;
if (blocklen[pos] > maxblocklen) blocklen[pos] = maxblocklen;
if ((blockpos[pos] & (sizeof sendbuf - 1)) + blocklen[pos] > sizeof sendbuf)
blocklen[pos] = sizeof sendbuf - (blockpos[pos] & (sizeof sendbuf - 1));
/* XXX: or could have the full block in post-buffer space */
sendprocessed += blocklen[pos];
blockeof[pos] = 0;
if (sendprocessed == sendbytes) {
blockeof[pos] = sendeof;
if (sendeof) sendeofprocessed = 1;
}
blocktransmissions[pos] = 0;
sendblock:
blocktransmissions[pos] += 1;
blocktime[pos] = recent;
blockid[pos] = nextmessageid;
if (!++nextmessageid) ++nextmessageid;
/* constraints: u multiple of 16; u >= 16; u <= 1088; u >= 48 + blocklen[pos] */
u = 64 + blocklen[pos];
if (u <= 192) u = 192;
else if (u <= 320) u = 320;
else if (u <= 576) u = 576;
else if (u <= 1088) u = 1088;
else die_internalerror();
if (blocklen[pos] < 0 || blocklen[pos] > 1024) die_internalerror();
byte_zero(buf + 8,u);
buf[7] = u / 16;
uint32_pack(buf + 8,blockid[pos]);
/* XXX: include any acknowledgments that have piled up */
uint16_pack(buf + 46,blockeof[pos] | (crypto_uint16) blocklen[pos]);
uint64_pack(buf + 48,blockpos[pos]);
byte_copy(buf + 8 + u - blocklen[pos],blocklen[pos],sendbuf + (blockpos[pos] & (sizeof sendbuf - 1)));
if (writeall(9,buf + 7,u + 1) == -1) die_fatal("unable to write descriptor 9",0,0);
lastblocktime = recent;
wantping = 0;
earliestblocktime_compute();
} while(0);
do { /* try receiving messages: */
if (!watch8) break;
r = read(8,buf,sizeof buf);
if (r == -1) if (errno == EINTR || errno == EWOULDBLOCK || errno == EAGAIN) break;
if (r == 0) die_badmessage();
if (r < 0) die_fatal("unable to read from file descriptor 8",0,0);
for (k = 0;k < r;++k) {
messagetodo[messagetodolen++] = buf[k];
u = 16 * (unsigned long long) messagetodo[0];
if (u < 16) die_badmessage();
if (u > 1088) die_badmessage();
if (messagetodolen == 1 + u) {
if (messagenum < INCOMING) {
pos = (messagefirst + messagenum) & (INCOMING - 1);
messagelen[pos] = messagetodo[0];
byte_copy(message[pos],u,messagetodo + 1);
++messagenum;
} else {
; /* drop tail */
}
messagetodolen = 0;
}
}
} while(0);
do { /* try processing a message: */
if (!messagenum) break;
if (tochild[1] >= 0 && receivewritten < receivebytes) break;
maxblocklen = 1024;
pos = messagefirst & (INCOMING - 1);
len = 16 * (unsigned long long) messagelen[pos];
do { /* handle this message if it's comprehensible: */
unsigned long long D;
unsigned long long SF;
unsigned long long startbyte;
unsigned long long stopbyte;
crypto_uint32 id;
long long i;
if (len < 48) break;
if (len > 1088) break;
id = uint32_unpack(message[pos] + 4);
for (i = 0;i < blocknum;++i) {
k = (blockfirst + i) & (OUTGOING - 1);
if (blockid[k] == id) {
rtt = recent - blocktime[k];
if (!rtt_average) {
nsecperblock = rtt;
rtt_average = rtt;
rtt_deviation = rtt / 2;
rtt_highwater = rtt;
rtt_lowwater = rtt;
}
/* Jacobson's retransmission timeout calculation: */
rtt_delta = rtt - rtt_average;
rtt_average += rtt_delta / 8;
if (rtt_delta < 0) rtt_delta = -rtt_delta;
rtt_delta -= rtt_deviation;
rtt_deviation += rtt_delta / 4;
rtt_timeout = rtt_average + 4 * rtt_deviation;
/* adjust for delayed acks with anti-spiking: */
rtt_timeout += 8 * nsecperblock;
/* recognizing top and bottom of congestion cycle: */
rtt_delta = rtt - rtt_highwater;
rtt_highwater += rtt_delta / 1024;
rtt_delta = rtt - rtt_lowwater;
if (rtt_delta > 0) rtt_lowwater += rtt_delta / 8192;
else rtt_lowwater += rtt_delta / 256;
if (rtt_average > rtt_highwater + 5000000) rtt_seenrecenthigh = 1;
else if (rtt_average < rtt_lowwater) rtt_seenrecentlow = 1;
if (recent >= lastspeedadjustment + 16 * nsecperblock) {
if (recent - lastspeedadjustment > 10000000000LL) {
nsecperblock = 1000000000; /* slow restart */
nsecperblock += randommod(nsecperblock / 8);
}
lastspeedadjustment = recent;
if (nsecperblock >= 131072) {
/* additive increase: adjust 1/N by a constant c */
/* rtt-fair additive increase: adjust 1/N by a constant c every nanosecond */
/* approximation: adjust 1/N by cN every N nanoseconds */
/* i.e., N <- 1/(1/N + cN) = N/(1 + cN^2) every N nanoseconds */
if (nsecperblock < 16777216) {
/* N/(1+cN^2) approx N - cN^3 */
u = nsecperblock / 131072;
nsecperblock -= u * u * u;
} else {
double d = nsecperblock;
nsecperblock = d/(1 + d*d / 2251799813685248.0);
}
}
if (rtt_phase == 0) {
if (rtt_seenolderhigh) {
rtt_phase = 1;
lastedge = recent;
nsecperblock += randommod(nsecperblock / 4);
}
} else {
if (rtt_seenolderlow) {
rtt_phase = 0;
}
}
rtt_seenolderhigh = rtt_seenrecenthigh;
rtt_seenolderlow = rtt_seenrecentlow;
rtt_seenrecenthigh = 0;
rtt_seenrecentlow = 0;
}
do {
if (recent - lastedge < 60000000000LL) {
if (recent < lastdoubling + 4 * nsecperblock + 64 * rtt_timeout + 5000000000LL) break;
} else {
if (recent < lastdoubling + 4 * nsecperblock + 2 * rtt_timeout) break;
}
if (nsecperblock <= 65535) break;
nsecperblock /= 2;
lastdoubling = recent;
if (lastedge) lastedge = recent;
} while(0);
}
}
stopbyte = uint64_unpack(message[pos] + 8);
acknowledged(0,stopbyte);
startbyte = stopbyte + (unsigned long long) uint32_unpack(message[pos] + 16);
stopbyte = startbyte + (unsigned long long) uint16_unpack(message[pos] + 20);
acknowledged(startbyte,stopbyte);
startbyte = stopbyte + (unsigned long long) uint16_unpack(message[pos] + 22);
stopbyte = startbyte + (unsigned long long) uint16_unpack(message[pos] + 24);
acknowledged(startbyte,stopbyte);
startbyte = stopbyte + (unsigned long long) uint16_unpack(message[pos] + 26);
stopbyte = startbyte + (unsigned long long) uint16_unpack(message[pos] + 28);
acknowledged(startbyte,stopbyte);
startbyte = stopbyte + (unsigned long long) uint16_unpack(message[pos] + 30);
stopbyte = startbyte + (unsigned long long) uint16_unpack(message[pos] + 32);
acknowledged(startbyte,stopbyte);
startbyte = stopbyte + (unsigned long long) uint16_unpack(message[pos] + 34);
stopbyte = startbyte + (unsigned long long) uint16_unpack(message[pos] + 36);
acknowledged(startbyte,stopbyte);
D = uint16_unpack(message[pos] + 38);
SF = D & (2048 + 4096);
D -= SF;
if (D > 1024) break;
if (48 + D > len) break;
startbyte = uint64_unpack(message[pos] + 40);
stopbyte = startbyte + D;
if (stopbyte > receivewritten + sizeof receivebuf) {
break;
/* of course, flow control would avoid this case */
}
if (SF) {
receiveeof = SF;
receivetotalbytes = stopbyte;
}
for (k = 0;k < D;++k) {
unsigned char ch = message[pos][len - D + k];
unsigned long long where = startbyte + k;
if (where >= receivewritten && where < receivewritten + sizeof receivebuf) {
receivevalid[where & (sizeof receivebuf - 1)] = 1;
receivebuf[where & (sizeof receivebuf - 1)] = ch;
}
}
for (;;) {
if (receivebytes >= receivewritten + sizeof receivebuf) break;
if (!receivevalid[receivebytes & (sizeof receivebuf - 1)]) break;
++receivebytes;
}
if (!uint32_unpack(message[pos])) break; /* never acknowledge a pure acknowledgment */
/* XXX: delay acknowledgments */
u = 192;
byte_zero(buf + 8,u);
buf[7] = u / 16;
byte_copy(buf + 12,4,message[pos]);
if (receiveeof && receivebytes == receivetotalbytes) {
uint64_pack(buf + 16,receivebytes + 1);
} else
uint64_pack(buf + 16,receivebytes);
/* XXX: incorporate selective acknowledgments */
if (writeall(9,buf + 7,u + 1) == -1) die_fatal("unable to write descriptor 9",0,0);
} while(0);
++messagefirst;
--messagenum;
} while(0);
do { /* try sending data to child: */
if (!watchtochild) break;
if (tochild[1] < 0) { receivewritten = receivebytes; break; }
if (receivewritten >= receivebytes) break;
pos = receivewritten & (sizeof receivebuf - 1);
len = receivebytes - receivewritten;
if (pos + len > sizeof receivebuf) len = sizeof receivebuf - pos;
r = write(tochild[1],receivebuf + pos,len);
if (r == -1) if (errno == EINTR || errno == EWOULDBLOCK || errno == EAGAIN) break;
if (r <= 0) {
close(tochild[1]);
tochild[1] = -1;
break;
}
byte_zero(receivevalid + pos,r);
receivewritten += r;
} while(0);
do { /* try closing pipe to child: */
if (!receiveeof) break;
if (receivewritten < receivetotalbytes) break;
if (tochild[1] < 0) break;
if (receiveeof == 4096)
; /* XXX: UNIX doesn't provide a way to signal an error through a pipe */
close(tochild[1]);
tochild[1] = -1;
} while(0);
/* XXX */
if (!childdied){
if (waitpid(child,&childstatus, WNOHANG) > 0) {
close(tochild[1]);
tochild[1] = -1;
childdied = 1;
}
}
}
if (!childdied) {
do {
r = waitpid(child,&childstatus,0);
} while (r == -1 && errno == EINTR);
}
finish:
if (!WIFEXITED(childstatus)) { errno = 0; die_fatal("process killed by signal",0,0); }
return WEXITSTATUS(childstatus);
}
