10c6347747
check_root() both checks to see if we are root (in the init namespace), and if we are drops to an unprivileged user. To make future cleanups simpler, split the checking for root (now in check_root()) from the actual dropping of privilege (now in drop_root()). Note that this does slightly alter semantics. Previously we would only setuid() if we were originally root (in the init namespace). Now we will always setuid() and setgid(), though it won't actually change anything if we weren't privileged to begin with. This also means that we will now always attempt to switch to the user specified with --runas, even if we aren't (init namespace) root to begin with. Obviously this will fail with an error if we weren't privileged to start with. --help and the man page are updated accordingly. Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
244 lines
6.1 KiB
C
244 lines
6.1 KiB
C
/* SPDX-License-Identifier: AGPL-3.0-or-later
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* Copyright (c) 2021 Red Hat GmbH
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* Author: Stefano Brivio <sbrivio@redhat.com>
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*/
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#ifndef UTIL_H
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#define UTIL_H
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void err(const char *format, ...);
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void warn(const char *format, ...);
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void info(const char *format, ...);
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void debug(const char *format, ...);
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extern int log_trace;
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void trace_init(int enable);
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#define trace(format, ...) \
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do { \
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if (log_trace) \
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debug(format, ##__VA_ARGS__); \
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} while (0)
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#ifndef SECCOMP_RET_KILL_PROCESS
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#define SECCOMP_RET_KILL_PROCESS SECCOMP_RET_KILL
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#endif
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#ifndef ETH_MAX_MTU
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#define ETH_MAX_MTU USHRT_MAX
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#endif
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#ifndef ETH_MIN_MTU
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#define ETH_MIN_MTU 68
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#endif
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#ifndef MIN
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#define MIN(x, y) (((x) < (y)) ? (x) : (y))
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#endif
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#ifndef MAX
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#define MAX(x, y) (((x) > (y)) ? (x) : (y))
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#endif
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#define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
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#define ROUND_DOWN(x, y) ((x) & ~((y) - 1))
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#define ROUND_UP(x, y) (((x) + (y) - 1) & ~((y) - 1))
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#define BIT(n) (1UL << (n))
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#define BITMAP_BIT(n) (BIT((n) % (sizeof(long) * 8)))
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#define BITMAP_WORD(n) (n / (sizeof(long) * 8))
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#define SWAP(a, b) \
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do { \
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__typeof__(a) __x = (a); (a) = (b); (b) = __x; \
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} while (0) \
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#define STRINGIFY(x) #x
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#define STR(x) STRINGIFY(x)
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#ifdef P_tmpdir
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#define TMPDIR P_tmpdir
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#else
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#define TMPDIR "/tmp"
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#endif
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#define FWRITE(path, buf, str) \
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do { \
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int flags = O_WRONLY | O_CLOEXEC; \
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int fd = open(path, flags); \
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\
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if (fd < 0 || \
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write(fd, buf, strlen(buf)) != (int)strlen(buf)) \
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warn(str); \
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if (fd >= 0) \
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close(fd); \
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} while (0)
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#define V4 0
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#define V6 1
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#define IP_VERSIONS 2
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#define ARRAY_SIZE(a) ((int)(sizeof(a) / sizeof((a)[0])))
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#define IN_INTERVAL(a, b, x) ((x) >= (a) && (x) <= (b))
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#define FD_PROTO(x, proto) \
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(IN_INTERVAL(c->proto.fd_min, c->proto.fd_max, (x)))
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#define PORT_EPHEMERAL_MIN ((1 << 15) + (1 << 14)) /* RFC 6335 */
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#define PORT_IS_EPHEMERAL(port) ((port) >= PORT_EPHEMERAL_MIN)
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#define MAC_ZERO ((uint8_t [ETH_ALEN]){ 0 })
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#define MAC_IS_ZERO(addr) (!memcmp((addr), MAC_ZERO, ETH_ALEN))
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#define NS_FN_STACK_SIZE (RLIMIT_STACK_VAL * 1024 / 4)
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#define NS_CALL(fn, arg) \
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do { \
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char ns_fn_stack[NS_FN_STACK_SIZE]; \
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\
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clone((fn), ns_fn_stack + sizeof(ns_fn_stack) / 2, \
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CLONE_VM | CLONE_VFORK | CLONE_FILES | SIGCHLD, \
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(void *)(arg)); \
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} while (0)
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#ifdef __has_warning
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# if __has_warning("-Wstringop-overread")
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# define PRAGMA_STRINGOP_OVERREAD_IGNORE \
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_Pragma("GCC diagnostic ignored \"-Wstringop-overread\"")
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# define PRAGMA_STRINGOP_OVERREAD_IGNORE_POP \
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_Pragma("GCC diagnostic pop")
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# else
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# define PRAGMA_STRINGOP_OVERREAD_IGNORE
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# define PRAGMA_STRINGOP_OVERREAD_IGNORE_POP
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# endif
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#else
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# if defined(__GNUC__) && __GNUC__ >= 11
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# define PRAGMA_STRINGOP_OVERREAD_IGNORE \
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_Pragma("GCC diagnostic ignored \"-Wstringop-overread\"")
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# define PRAGMA_STRINGOP_OVERREAD_IGNORE_POP \
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_Pragma("GCC diagnostic pop")
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# else
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# define PRAGMA_STRINGOP_OVERREAD_IGNORE
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# define PRAGMA_STRINGOP_OVERREAD_IGNORE_POP
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# endif
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#endif
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#if __BYTE_ORDER == __BIG_ENDIAN
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#define L2_BUF_ETH_IP4_INIT \
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{ \
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.h_dest = { 0 }, \
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.h_source = { 0 }, \
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.h_proto = ETH_P_IP, \
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}
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#else
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#define L2_BUF_ETH_IP4_INIT \
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{ \
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.h_dest = { 0 }, \
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.h_source = { 0 }, \
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.h_proto = __bswap_constant_16(ETH_P_IP), \
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}
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#endif
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#if __BYTE_ORDER == __BIG_ENDIAN
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#define L2_BUF_ETH_IP6_INIT \
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{ \
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.h_dest = { 0 }, \
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.h_source = { 0 }, \
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.h_proto = ETH_P_IPV6, \
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}
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#else
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#define L2_BUF_ETH_IP6_INIT \
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{ \
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.h_dest = { 0 }, \
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.h_source = { 0 }, \
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.h_proto = __bswap_constant_16(ETH_P_IPV6), \
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}
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#endif
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#define L2_BUF_IP4_INIT(proto) \
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{ \
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.version = 4, \
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.ihl = 5, \
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.tos = 0, \
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.tot_len = 0, \
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.id = 0, \
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.frag_off = 0, \
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.ttl = 255, \
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.protocol = (proto), \
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.saddr = 0, \
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.daddr = 0, \
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}
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#define L2_BUF_IP6_INIT(proto) \
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{ \
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.priority = 0, \
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.version = 6, \
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.flow_lbl = { 0 }, \
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.payload_len = 0, \
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.nexthdr = (proto), \
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.hop_limit = 255, \
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.saddr = IN6ADDR_ANY_INIT, \
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.daddr = IN6ADDR_ANY_INIT, \
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}
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#define RCVBUF_BIG (2UL * 1024 * 1024)
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#define SNDBUF_BIG (4UL * 1024 * 1024)
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#define SNDBUF_SMALL (128UL * 1024)
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#include <net/if.h>
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#include <limits.h>
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#include <stdarg.h>
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#include "packet.h"
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struct ctx;
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struct ipv6hdr {
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#pragma GCC diagnostic ignored "-Wpedantic"
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#if __BYTE_ORDER == __BIG_ENDIAN
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uint8_t version:4,
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priority:4;
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#else
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uint8_t priority:4,
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version:4;
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#endif
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#pragma GCC diagnostic pop
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uint8_t flow_lbl[3];
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uint16_t payload_len;
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uint8_t nexthdr;
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uint8_t hop_limit;
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struct in6_addr saddr;
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struct in6_addr daddr;
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};
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struct ipv6_opt_hdr {
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uint8_t nexthdr;
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uint8_t hdrlen;
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/*
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* TLV encoded option data follows.
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*/
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} __attribute__((packed)); /* required for some archs */
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__attribute__ ((weak)) int ffsl(long int i) { return __builtin_ffsl(i); }
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void __openlog(const char *ident, int option, int facility);
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void passt_vsyslog(int pri, const char *format, va_list ap);
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void __setlogmask(int mask);
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char *ipv6_l4hdr(const struct pool *p, int index, size_t offset, uint8_t *proto,
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size_t *dlen);
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int sock_l4(const struct ctx *c, int af, uint8_t proto,
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const void *bind_addr, uint16_t port, uint32_t data);
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void sock_probe_mem(struct ctx *c);
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int timespec_diff_ms(const struct timespec *a, const struct timespec *b);
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void bitmap_set(uint8_t *map, int bit);
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void bitmap_clear(uint8_t *map, int bit);
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int bitmap_isset(const uint8_t *map, int bit);
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char *line_read(char *buf, size_t len, int fd);
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void procfs_scan_listen(struct ctx *c, uint8_t proto, int ip_version, int ns,
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uint8_t *map, uint8_t *exclude);
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void drop_caps(void);
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void check_root(uid_t *uid, gid_t *gid);
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void drop_root(uid_t uid, gid_t gid);
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int ns_enter(const struct ctx *c);
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void write_pidfile(int fd, pid_t pid);
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int __daemon(int pidfile_fd, int devnull_fd);
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int fls(unsigned long x);
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#endif /* UTIL_H */
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