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#include "resolve.h"
/* ping HOST|IP - originate ICMP echo requests via the kernel socket layer.
Resolves a hostname via DNS first (resolve.h); default target 10.0.0.1. No
SLIP/IP/checksums here - the kernel owns all of that. */
/* rbuf is first + large so namebuf/dst land past the arg string at 0xA000 */
static unsigned char rbuf[96];
static unsigned char namebuf[64];
static unsigned char dst[4];
static unsigned char payload[4];
static void put_ip(unsigned char *ip) {
unsigned char i;
for (i = 0; i < 4; i++) { putu(ip[i]); if (i < 3) putc('.'); }
}
/* wait up to ~2s for an echo reply without blocking in the kernel: a lost
reply (some hosts rate-limit ICMP) must cost one "timeout" line, not
minutes wedged inside net_recv's pump-counted wait. */
static unsigned char wait_reply(unsigned char s) {
unsigned char t, r;
for (t = 0; t < 40; t++) {
r = net_recv_nb(s, rbuf, (unsigned char)sizeof(rbuf));
if (r != 0xFE) return r; /* reply (or error) */
msleep(50);
}
return 0xFF; /* ~2s with no reply */
}
void main(void) {
char *arg;
unsigned char s, seq, got = 0, i;
arg = getargs();
if (!arg || !*arg) { dst[0] = 10; dst[1] = 0; dst[2] = 0; dst[3] = 1; }
else {
for (i = 0; arg[i] && i < 63; i++) namebuf[i] = (unsigned char)arg[i];
namebuf[i] = 0;
if (!resolve((char *)namebuf, dst)) {
puts("ping: cannot resolve "); puts((char *)namebuf); nl(); sexit(1);
}
}
payload[0] = 'g'; payload[1] = 'b'; payload[2] = 'o'; payload[3] = 's';
s = net_socket(SOCK_ICMP);
if (s == 0xFF) { puts("ping: no socket"); nl(); sexit(1); }
net_connect(s, dst, 0);
puts("PING "); put_ip(dst); nl();
for (seq = 1; seq <= 4; seq++) {
net_send(s, payload, 4);
if (wait_reply(s) != 0xFF) {
got++;
puts(" reply from "); put_ip(dst); puts(" seq="); putu(seq); nl();
} else {
puts(" seq="); putu(seq); puts(" timeout"); nl();
}
if (seq < 4) msleep(800); /* pace like real ping */
}
puts("-- "); putu(got); puts("/4 received"); nl();
net_close(s);
}
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