iptables -t mangle -A ISTIO_PRERT -p tcp -m tcp --dport 15008 -m mark ! --mark 0x539/0xfff -j TPROXY --on-port 15008 --tproxy-mark 0x111/0xfff
iptables -t mangle -A ISTIO_PRERT -p tcp -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
iptables -t mangle -A ISTIO_PRERT ! -d 127.0.0.1/32 -p tcp -m mark ! --mark 0x539/0xfff -j TPROXY --on-port 15006 --tproxy-mark 0x111/0xfff

-A PREROUTING -p tcp -m mark --mark 1337 -j CONNMARK --save-mark
-A OUTPUT -p tcp -o lo -m mark --mark 1337 -j RETURN
-A OUTPUT ! -d 127.0.0.1/32 -p tcp -o lo -m owner --uid-owner 1337 -j MARK --set-mark 1338
-A OUTPUT ! -d 127.0.0.1/32 -p tcp -o lo -m owner --gid-owner 1337 -j MARK --set-mark 1338
-A OUTPUT -p tcp -m connmark --mark 1337 -j CONNMARK --restore-mark
-I ISTIO_INBOUND 1 -p tcp -m mark --mark 1337 -j RETURN

import sys

import pytest
from fastapi._compat import PYDANTIC_V2

needs_py39 = pytest.mark.skipif(sys.version_info < (3, 9), reason="requires python3.9+")
needs_py310 = pytest.mark.skipif(
    sys.version_info < (3, 10), reason="requires python3.10+"
)
needs_pydanticv2 = pytest.mark.skipif(not PYDANTIC_V2, reason="requires Pydantic v2")

  }

  @Override
  public synchronized void mark(int readlimit) {
    in.mark(readlimit);
    mark = count;
    // it's okay to mark even if mark isn't supported, as reset won't work
  }

  @Override
  public synchronized void reset() throws IOException {
    if (!in.markSupported()) {
      throw new IOException("Mark not supported");
    }
    if (mark == -1) {
      throw new IOException("Mark not set");
    }

	// From here on, we should be only inserting rules into our custom chains.

	// CLI: -A ISTIO_PRERT -m mark --mark 0x539/0xfff -j CONNMARK --set-xmark 0x111/0xfff
	//
	// DESC: If we have a packet mark, set a connmark.
	iptablesBuilder.AppendRule(iptableslog.UndefinedCommand, ChainInpodPrerouting, iptablesconstants.MANGLE, "-m", "mark",
		"--mark", inpodMark,
		"-j", "CONNMARK",
		"--set-xmark", inpodTproxyMark)

        scanner.next();
        scanner.mark();
        scanner.find(';');
        String value = ENTITIES.get(scanner.region().toLowerCase());
        buffer.append(value);
        scanner.next();
    }

    private void parseHtmlEncodedChar(StringBuilder buffer) {
        scanner.next(2);
        scanner.mark();
        scanner.find(';');

                        mark = si + 1;
                        state = 5;
                    }
                    break;
                case 5:
                    if (ch == '=') {
                        key = str.substring(mark, si).trim();
                        mark = si + 1;
                    } else if (ch == ',' || ch == ']') {

-A PREROUTING -p tcp -m mark --mark 1337 -j CONNMARK --save-mark
-A OUTPUT -p tcp -o lo -m mark --mark 1337 -j RETURN
-A OUTPUT ! -d 127.0.0.1/32 -p tcp -o lo -m owner --uid-owner 1000670000 -j MARK --set-mark 1338
-A OUTPUT ! -d 127.0.0.1/32 -p tcp -o lo -m owner --gid-owner 1000670001 -j MARK --set-mark 1338
-A OUTPUT -p tcp -m connmark --mark 1337 -j CONNMARK --restore-mark
-I ISTIO_INBOUND 1 -p tcp -m mark --mark 1337 -j RETURN

iptables -t mangle -A ISTIO_PRERT ! -d 127.0.0.1/32 -p tcp -m mark ! --mark 0x539/0xfff -j TPROXY --on-port 15006 --tproxy-mark 0x111/0xfff
iptables -t mangle -A ISTIO_OUTPUT -m connmark --mark 0x111/0xfff -j CONNMARK --restore-mark --nfmask 0xffffffff --ctmask 0xffffffff
iptables -t nat -A ISTIO_OUTPUT ! -o lo -p udp -m udp --dport 53 -j REDIRECT --to-port 15053
iptables -t nat -A ISTIO_OUTPUT -p tcp -m mark --mark 0x111/0xfff -j ACCEPT

    assertEquals(string, readFully(reader));
    assertFullyRead(reader);

    // reset, skip, mark, then read the rest
    reader.reset();
    assertEquals(5, reader.skip(5));
    reader.mark(Integer.MAX_VALUE);
    assertEquals(string.substring(5), readFully(reader));
    assertFullyRead(reader);

    // reset to the mark and then read the rest
    reader.reset();
    assertEquals(string.substring(5), readFully(reader));