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conf.c
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// SPDX-License-Identifier: GPL-2.0-or-later
/* PASST - Plug A Simple Socket Transport
* for qemu/UNIX domain socket mode
*
* PASTA - Pack A Subtle Tap Abstraction
* for network namespace/tap device mode
*
* conf.c - Configuration settings and option parsing
*
* Copyright (c) 2020-2021 Red Hat GmbH
* Author: Stefano Brivio <[email protected]>
*/
#include <arpa/inet.h>
#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
#include <string.h>
#include <sched.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <limits.h>
#include <grp.h>
#include <pwd.h>
#include <unistd.h>
#include <signal.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdio.h>
#include <stdbool.h>
#include <syslog.h>
#include <time.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include "util.h"
#include "ip.h"
#include "passt.h"
#include "netlink.h"
#include "tap.h"
#include "udp.h"
#include "tcp.h"
#include "pasta.h"
#include "lineread.h"
#include "isolation.h"
#include "log.h"
#include "vhost_user.h"
#define NETNS_RUN_DIR "/run/netns"
#define IP4_LL_GUEST_ADDR (struct in_addr){ htonl_constant(0xa9fe0201) }
/* 169.254.2.1, libslirp default: 10.0.2.1 */
#define IP4_LL_GUEST_GW (struct in_addr){ htonl_constant(0xa9fe0202) }
/* 169.254.2.2, libslirp default: 10.0.2.2 */
#define IP4_LL_PREFIX_LEN 16
#define IP6_LL_GUEST_GW (struct in6_addr) \
{{{ 0xfe, 0x80, 0, 0, 0, 0, 0, 0, \
0, 0, 0, 0, 0, 0, 0, 0x01 }}}
const char *pasta_default_ifn = "tap0";
/**
* next_chunk - Return the next piece of a string delimited by a character
* @s: String to search
* @c: Delimiter character
*
* Return: If another @c is found in @s, returns a pointer to the
* character *after* the delimiter, if no further @c is in @s,
* return NULL
*/
static char *next_chunk(const char *s, char c)
{
char *sep = strchr(s, c);
return sep ? sep + 1 : NULL;
}
/**
* port_range - Represents a non-empty range of ports
* @first: First port number in the range
* @last: Last port number in the range (inclusive)
*
* Invariant: @last >= @first
*/
struct port_range {
in_port_t first, last;
};
/**
* parse_port_range() - Parse a range of port numbers '<first>[-<last>]'
* @s: String to parse
* @endptr: Update to the character after the parsed range (similar to
* strtol() etc.)
* @range: Update with the parsed values on success
*
* Return: -EINVAL on parsing error, -ERANGE on out of range port
* numbers, 0 on success
*/
static int parse_port_range(const char *s, char **endptr,
struct port_range *range)
{
unsigned long first, last;
last = first = strtoul(s, endptr, 10);
if (*endptr == s) /* Parsed nothing */
return -EINVAL;
if (**endptr == '-') { /* we have a last value too */
const char *lasts = *endptr + 1;
last = strtoul(lasts, endptr, 10);
if (*endptr == lasts) /* Parsed nothing */
return -EINVAL;
}
if ((last < first) || (last >= NUM_PORTS))
return -ERANGE;
range->first = first;
range->last = last;
return 0;
}
/**
* conf_ports() - Parse port configuration options, initialise UDP/TCP sockets
* @c: Execution context
* @optname: Short option name, t, T, u, or U
* @optarg: Option argument (port specification)
* @fwd: Pointer to @fwd_ports to be updated
*/
static void conf_ports(const struct ctx *c, char optname, const char *optarg,
struct fwd_ports *fwd)
{
union inany_addr addr_buf = inany_any6, *addr = &addr_buf;
char buf[BUFSIZ], *spec, *ifname = NULL, *p;
bool exclude_only = true, bound_one = false;
uint8_t exclude[PORT_BITMAP_SIZE] = { 0 };
unsigned i;
int ret;
if (!strcmp(optarg, "none")) {
if (fwd->mode)
goto mode_conflict;
fwd->mode = FWD_NONE;
return;
}
if ((optname == 't' || optname == 'T') && c->no_tcp)
die("TCP port forwarding requested but TCP is disabled");
if ((optname == 'u' || optname == 'U') && c->no_udp)
die("UDP port forwarding requested but UDP is disabled");
if (!strcmp(optarg, "auto")) {
if (fwd->mode)
goto mode_conflict;
if (c->mode != MODE_PASTA)
die("'auto' port forwarding is only allowed for pasta");
fwd->mode = FWD_AUTO;
return;
}
if (!strcmp(optarg, "all")) {
if (fwd->mode)
goto mode_conflict;
if (c->mode == MODE_PASTA)
die("'all' port forwarding is only allowed for passt");
fwd->mode = FWD_ALL;
/* Skip port 0. It has special meaning for many socket APIs, so
* trying to bind it is not really safe.
*/
for (i = 1; i < NUM_PORTS; i++) {
if (fwd_port_is_ephemeral(i))
continue;
bitmap_set(fwd->map, i);
if (optname == 't') {
ret = tcp_sock_init(c, NULL, NULL, i);
if (ret == -ENFILE || ret == -EMFILE)
goto enfile;
if (!ret)
bound_one = true;
} else if (optname == 'u') {
ret = udp_sock_init(c, 0, NULL, NULL, i);
if (ret == -ENFILE || ret == -EMFILE)
goto enfile;
if (!ret)
bound_one = true;
}
}
if (!bound_one)
goto bind_all_fail;
return;
}
if (fwd->mode > FWD_SPEC)
die("Specific ports cannot be specified together with all/none/auto");
fwd->mode = FWD_SPEC;
strncpy(buf, optarg, sizeof(buf) - 1);
if ((spec = strchr(buf, '/'))) {
*spec = 0;
spec++;
if (optname != 't' && optname != 'u')
goto bad;
if ((ifname = strchr(buf, '%'))) {
*ifname = 0;
ifname++;
/* spec is already advanced one past the '/',
* so the length of the given ifname is:
* (spec - ifname - 1)
*/
if (spec - ifname - 1 >= IFNAMSIZ)
goto bad;
}
if (ifname == buf + 1) { /* Interface without address */
addr = NULL;
} else {
p = buf;
/* Allow square brackets for IPv4 too for convenience */
if (*p == '[' && p[strlen(p) - 1] == ']') {
p[strlen(p) - 1] = '\0';
p++;
}
if (!inany_pton(p, addr))
goto bad;
}
} else {
spec = buf;
addr = NULL;
}
/* Mark all exclusions first, they might be given after base ranges */
p = spec;
do {
struct port_range xrange;
if (*p != '~') {
/* Not an exclude range, parse later */
exclude_only = false;
continue;
}
p++;
if (parse_port_range(p, &p, &xrange))
goto bad;
if ((*p != '\0') && (*p != ',')) /* Garbage after the range */
goto bad;
for (i = xrange.first; i <= xrange.last; i++) {
if (bitmap_isset(exclude, i))
die("Overlapping excluded ranges %s", optarg);
bitmap_set(exclude, i);
}
} while ((p = next_chunk(p, ',')));
if (exclude_only) {
/* Skip port 0. It has special meaning for many socket APIs, so
* trying to bind it is not really safe.
*/
for (i = 1; i < NUM_PORTS; i++) {
if (fwd_port_is_ephemeral(i) ||
bitmap_isset(exclude, i))
continue;
bitmap_set(fwd->map, i);
if (optname == 't') {
ret = tcp_sock_init(c, addr, ifname, i);
if (ret == -ENFILE || ret == -EMFILE)
goto enfile;
if (!ret)
bound_one = true;
} else if (optname == 'u') {
ret = udp_sock_init(c, 0, addr, ifname, i);
if (ret == -ENFILE || ret == -EMFILE)
goto enfile;
if (!ret)
bound_one = true;
} else {
/* No way to check in advance for -T and -U */
bound_one = true;
}
}
if (!bound_one)
goto bind_all_fail;
return;
}
/* Now process base ranges, skipping exclusions */
p = spec;
do {
struct port_range orig_range, mapped_range;
if (*p == '~')
/* Exclude range, already parsed */
continue;
if (parse_port_range(p, &p, &orig_range))
goto bad;
if (*p == ':') { /* There's a range to map to as well */
if (parse_port_range(p + 1, &p, &mapped_range))
goto bad;
if ((mapped_range.last - mapped_range.first) !=
(orig_range.last - orig_range.first))
goto bad;
} else {
mapped_range = orig_range;
}
if ((*p != '\0') && (*p != ',')) /* Garbage after the ranges */
goto bad;
for (i = orig_range.first; i <= orig_range.last; i++) {
if (bitmap_isset(fwd->map, i))
warn(
"Altering mapping of already mapped port number: %s", optarg);
if (bitmap_isset(exclude, i))
continue;
bitmap_set(fwd->map, i);
fwd->delta[i] = mapped_range.first - orig_range.first;
ret = 0;
if (optname == 't')
ret = tcp_sock_init(c, addr, ifname, i);
else if (optname == 'u')
ret = udp_sock_init(c, 0, addr, ifname, i);
if (ret)
goto bind_fail;
}
} while ((p = next_chunk(p, ',')));
return;
enfile:
die("Can't open enough sockets for port specifier: %s", optarg);
bad:
die("Invalid port specifier %s", optarg);
mode_conflict:
die("Port forwarding mode '%s' conflicts with previous mode", optarg);
bind_fail:
die("Failed to bind port %u (%s) for option '-%c %s', exiting",
i, strerror_(-ret), optname, optarg);
bind_all_fail:
die("Failed to bind any port for '-%c %s', exiting", optname, optarg);
}
/**
* add_dns4() - Possibly add the IPv4 address of a DNS resolver to configuration
* @c: Execution context
* @addr: Guest nameserver IPv4 address
* @idx: Index of free entry in array of IPv4 resolvers
*
* Return: Number of entries added (0 or 1)
*/
static unsigned add_dns4(struct ctx *c, const struct in_addr *addr,
unsigned idx)
{
if (idx >= ARRAY_SIZE(c->ip4.dns))
return 0;
c->ip4.dns[idx] = *addr;
return 1;
}
/**
* add_dns6() - Possibly add the IPv6 address of a DNS resolver to configuration
* @c: Execution context
* @addr: Guest nameserver IPv6 address
* @idx: Index of free entry in array of IPv6 resolvers
*
* Return: Number of entries added (0 or 1)
*/
static unsigned add_dns6(struct ctx *c, const struct in6_addr *addr,
unsigned idx)
{
if (idx >= ARRAY_SIZE(c->ip6.dns))
return 0;
c->ip6.dns[idx] = *addr;
return 1;
}
/**
* add_dns_resolv() - Possibly add ns from host resolv.conf to configuration
* @c: Execution context
* @nameserver: Nameserver address string from /etc/resolv.conf
* @idx4: Pointer to index of current entry in array of IPv4 resolvers
* @idx6: Pointer to index of current entry in array of IPv6 resolvers
*
* @idx4 or @idx6 may be NULL, in which case resolvers of the corresponding type
* are ignored.
*/
static void add_dns_resolv(struct ctx *c, const char *nameserver,
unsigned *idx4, unsigned *idx6)
{
struct in6_addr ns6;
struct in_addr ns4;
if (idx4 && inet_pton(AF_INET, nameserver, &ns4)) {
if (IN4_IS_ADDR_UNSPECIFIED(&c->ip4.dns_host))
c->ip4.dns_host = ns4;
/* Guest or container can only access local addresses via
* redirect
*/
if (IN4_IS_ADDR_LOOPBACK(&ns4)) {
if (IN4_IS_ADDR_UNSPECIFIED(&c->ip4.map_host_loopback))
return;
ns4 = c->ip4.map_host_loopback;
if (IN4_IS_ADDR_UNSPECIFIED(&c->ip4.dns_match))
c->ip4.dns_match = c->ip4.map_host_loopback;
}
*idx4 += add_dns4(c, &ns4, *idx4);
}
if (idx6 && inet_pton(AF_INET6, nameserver, &ns6)) {
if (IN6_IS_ADDR_UNSPECIFIED(&c->ip6.dns_host))
c->ip6.dns_host = ns6;
/* Guest or container can only access local addresses via
* redirect
*/
if (IN6_IS_ADDR_LOOPBACK(&ns6)) {
if (IN6_IS_ADDR_UNSPECIFIED(&c->ip6.map_host_loopback))
return;
ns6 = c->ip6.map_host_loopback;
if (IN6_IS_ADDR_UNSPECIFIED(&c->ip6.dns_match))
c->ip6.dns_match = c->ip6.map_host_loopback;
}
*idx6 += add_dns6(c, &ns6, *idx6);
}
}
/**
* get_dns() - Get nameserver addresses from local /etc/resolv.conf
* @c: Execution context
*/
static void get_dns(struct ctx *c)
{
int dns4_set, dns6_set, dnss_set, dns_set, fd;
unsigned dns4_idx = 0, dns6_idx = 0;
struct fqdn *s = c->dns_search;
struct lineread resolvconf;
ssize_t line_len;
char *line, *end;
const char *p;
dns4_set = !c->ifi4 || !IN4_IS_ADDR_UNSPECIFIED(&c->ip4.dns[0]);
dns6_set = !c->ifi6 || !IN6_IS_ADDR_UNSPECIFIED(&c->ip6.dns[0]);
dnss_set = !!*s->n || c->no_dns_search;
dns_set = (dns4_set && dns6_set) || c->no_dns;
if (dns_set && dnss_set)
return;
if ((fd = open("/etc/resolv.conf", O_RDONLY | O_CLOEXEC)) < 0)
goto out;
lineread_init(&resolvconf, fd);
while ((line_len = lineread_get(&resolvconf, &line)) > 0) {
if (!dns_set && strstr(line, "nameserver ") == line) {
p = strrchr(line, ' ');
if (!p)
continue;
end = strpbrk(line, "%\n");
if (end)
*end = 0;
add_dns_resolv(c, p + 1,
dns4_set ? NULL : &dns4_idx,
dns6_set ? NULL : &dns6_idx);
} else if (!dnss_set && strstr(line, "search ") == line &&
s == c->dns_search) {
end = strpbrk(line, "\n");
if (end)
*end = 0;
/* cppcheck-suppress strtokCalled */
if (!strtok(line, " \t"))
continue;
while (s - c->dns_search < ARRAY_SIZE(c->dns_search) - 1
/* cppcheck-suppress strtokCalled */
&& (p = strtok(NULL, " \t"))) {
strncpy(s->n, p, sizeof(c->dns_search[0]) - 1);
s++;
*s->n = 0;
}
}
}
if (line_len < 0)
warn_perror("Error reading /etc/resolv.conf");
close(fd);
out:
if (!dns_set) {
if (!(dns4_idx + dns6_idx))
warn("Couldn't get any nameserver address");
if (c->no_dhcp_dns)
return;
if (c->ifi4 && !c->no_dhcp &&
IN4_IS_ADDR_UNSPECIFIED(&c->ip4.dns[0]))
warn("No IPv4 nameserver available for DHCP");
if (c->ifi6 && ((!c->no_ndp && !c->no_ra) || !c->no_dhcpv6) &&
IN6_IS_ADDR_UNSPECIFIED(&c->ip6.dns[0]))
warn("No IPv6 nameserver available for NDP/DHCPv6");
}
}
/**
* conf_netns_opt() - Parse --netns option
* @netns: buffer of size PATH_MAX, updated with netns path
* @arg: --netns argument
*/
static void conf_netns_opt(char *netns, const char *arg)
{
int ret;
if (!strchr(arg, '/')) {
/* looks like a netns name */
ret = snprintf(netns, PATH_MAX, "%s/%s", NETNS_RUN_DIR, arg);
} else {
/* otherwise assume it's a netns path */
ret = snprintf(netns, PATH_MAX, "%s", arg);
}
if (ret <= 0 || ret > PATH_MAX)
die("Network namespace name/path %s too long", arg);
}
/**
* conf_pasta_ns() - Validate all pasta namespace options
* @netns_only: Don't use userns, may be updated
* @userns: buffer of size PATH_MAX, initially contains --userns
* argument (may be empty), updated with userns path
* @netns: buffer of size PATH_MAX, initial contains --netns
* argument (may be empty), updated with netns path
* @optind: Index of first non-option argument
* @argc: Number of arguments
* @argv: Command line arguments
*/
static void conf_pasta_ns(int *netns_only, char *userns, char *netns,
int optind, int argc, char *argv[])
{
if (*netns && optind != argc)
die("Both --netns and PID or command given");
if (optind + 1 == argc) {
char *endptr;
long pidval;
pidval = strtol(argv[optind], &endptr, 10);
if (!*endptr) {
/* Looks like a pid */
if (pidval < 0 || pidval > INT_MAX)
die("Invalid PID %s", argv[optind]);
if (snprintf_check(netns, PATH_MAX,
"/proc/%ld/ns/net", pidval))
die_perror("Can't build netns path");
if (!*userns) {
if (snprintf_check(userns, PATH_MAX,
"/proc/%ld/ns/user", pidval))
die_perror("Can't build userns path");
}
}
}
/* Attaching to a netns/PID, with no userns given */
if (*netns && !*userns)
*netns_only = 1;
}
/** conf_ip4_prefix() - Parse an IPv4 prefix length or netmask
* @arg: Netmask in dotted decimal or prefix length
*
* Return: Validated prefix length on success, -1 on failure
*/
static int conf_ip4_prefix(const char *arg)
{
struct in_addr mask;
unsigned long len;
if (inet_pton(AF_INET, arg, &mask)) {
in_addr_t hmask = ntohl(mask.s_addr);
len = __builtin_popcount(hmask);
if ((hmask << len) != 0)
return -1;
} else {
errno = 0;
len = strtoul(optarg, NULL, 0);
if (len > 32 || errno)
return -1;
}
return len;
}
/**
* conf_ip4() - Verify or detect IPv4 support, get relevant addresses
* @ifi: Host interface to attempt (0 to determine one)
* @ip4: IPv4 context (will be written)
*
* Return: Interface index for IPv4, or 0 on failure.
*/
static unsigned int conf_ip4(unsigned int ifi, struct ip4_ctx *ip4)
{
if (!ifi)
ifi = nl_get_ext_if(nl_sock, AF_INET);
if (!ifi) {
debug("Failed to detect external interface for IPv4");
return 0;
}
if (IN4_IS_ADDR_UNSPECIFIED(&ip4->guest_gw)) {
int rc = nl_route_get_def(nl_sock, ifi, AF_INET,
&ip4->guest_gw);
if (rc < 0) {
debug("Couldn't discover IPv4 gateway address: %s",
strerror_(-rc));
return 0;
}
}
if (IN4_IS_ADDR_UNSPECIFIED(&ip4->addr)) {
int rc = nl_addr_get(nl_sock, ifi, AF_INET,
&ip4->addr, &ip4->prefix_len, NULL);
if (rc < 0) {
debug("Couldn't discover IPv4 address: %s",
strerror_(-rc));
return 0;
}
}
if (!ip4->prefix_len) {
in_addr_t addr = ntohl(ip4->addr.s_addr);
if (IN_CLASSA(addr))
ip4->prefix_len = (32 - IN_CLASSA_NSHIFT);
else if (IN_CLASSB(addr))
ip4->prefix_len = (32 - IN_CLASSB_NSHIFT);
else if (IN_CLASSC(addr))
ip4->prefix_len = (32 - IN_CLASSC_NSHIFT);
else
ip4->prefix_len = 32;
}
ip4->addr_seen = ip4->addr;
ip4->our_tap_addr = ip4->guest_gw;
if (IN4_IS_ADDR_UNSPECIFIED(&ip4->addr))
return 0;
return ifi;
}
/**
* conf_ip4_local() - Configure IPv4 addresses and attributes for local mode
* @ip4: IPv4 context (will be written)
*/
static void conf_ip4_local(struct ip4_ctx *ip4)
{
ip4->addr_seen = ip4->addr = IP4_LL_GUEST_ADDR;
ip4->our_tap_addr = ip4->guest_gw = IP4_LL_GUEST_GW;
ip4->prefix_len = IP4_LL_PREFIX_LEN;
ip4->no_copy_addrs = ip4->no_copy_routes = true;
}
/**
* conf_ip6() - Verify or detect IPv6 support, get relevant addresses
* @ifi: Host interface to attempt (0 to determine one)
* @ip6: IPv6 context (will be written)
*
* Return: Interface index for IPv6, or 0 on failure.
*/
static unsigned int conf_ip6(unsigned int ifi, struct ip6_ctx *ip6)
{
int prefix_len = 0;
int rc;
if (!ifi)
ifi = nl_get_ext_if(nl_sock, AF_INET6);
if (!ifi) {
debug("Failed to detect external interface for IPv6");
return 0;
}
if (IN6_IS_ADDR_UNSPECIFIED(&ip6->guest_gw)) {
rc = nl_route_get_def(nl_sock, ifi, AF_INET6, &ip6->guest_gw);
if (rc < 0) {
debug("Couldn't discover IPv6 gateway address: %s",
strerror_(-rc));
return 0;
}
}
rc = nl_addr_get(nl_sock, ifi, AF_INET6,
IN6_IS_ADDR_UNSPECIFIED(&ip6->addr) ? &ip6->addr : NULL,
&prefix_len, &ip6->our_tap_ll);
if (rc < 0) {
debug("Couldn't discover IPv6 address: %s", strerror_(-rc));
return 0;
}
ip6->addr_seen = ip6->addr;
if (IN6_IS_ADDR_LINKLOCAL(&ip6->guest_gw))
ip6->our_tap_ll = ip6->guest_gw;
if (IN6_IS_ADDR_UNSPECIFIED(&ip6->addr) ||
IN6_IS_ADDR_UNSPECIFIED(&ip6->our_tap_ll))
return 0;
return ifi;
}
/**
* conf_ip6_local() - Configure IPv6 addresses and attributes for local mode
* @ip6: IPv6 context (will be written)
*/
static void conf_ip6_local(struct ip6_ctx *ip6)
{
ip6->our_tap_ll = ip6->guest_gw = IP6_LL_GUEST_GW;
ip6->no_copy_addrs = ip6->no_copy_routes = true;
}
/**
* usage() - Print usage, exit with given status code
* @name: Executable name
* @f: Stream to print usage info to
* @status: Status code for exit()
*/
static void usage(const char *name, FILE *f, int status)
{
if (strstr(name, "pasta")) {
FPRINTF(f, "Usage: %s [OPTION]... [COMMAND] [ARGS]...\n", name);
FPRINTF(f, " %s [OPTION]... PID\n", name);
FPRINTF(f, " %s [OPTION]... --netns [PATH|NAME]\n", name);
FPRINTF(f,
"\n"
"Without PID or --netns, run the given command or a\n"
"default shell in a new network and user namespace, and\n"
"connect it via pasta.\n");
} else {
FPRINTF(f, "Usage: %s [OPTION]...\n", name);
}
FPRINTF(f,
"\n"
" -d, --debug Be verbose\n"
" --trace Be extra verbose, implies --debug\n"
" -q, --quiet Don't print informational messages\n"
" -f, --foreground Don't run in background\n"
" default: run in background\n"
" -l, --log-file PATH Log (only) to given file\n"
" --log-size BYTES Maximum size of log file\n"
" default: 1 MiB\n"
" --runas UID|UID:GID Run as given UID, GID, which can be\n"
" numeric, or login and group names\n"
" default: drop to user \"nobody\"\n"
" -h, --help Display this help message and exit\n"
" --version Show version and exit\n");
if (strstr(name, "pasta")) {
FPRINTF(f,
" -I, --ns-ifname NAME namespace interface name\n"
" default: same interface name as external one\n");
} else {
FPRINTF(f,
" -s, --socket, --socket-path PATH UNIX domain socket path\n"
" default: probe free path starting from "
UNIX_SOCK_PATH "\n", 1);
FPRINTF(f,
" --vhost-user Enable vhost-user mode\n"
" UNIX domain socket is provided by -s option\n"
" --print-capabilities print back-end capabilities in JSON format,\n"
" only meaningful for vhost-user mode\n");
}
FPRINTF(f,
" -F, --fd FD Use FD as pre-opened connected socket\n"
" -p, --pcap FILE Log tap-facing traffic to pcap file\n"
" -P, --pid FILE Write own PID to the given file\n"
" -m, --mtu MTU Assign MTU via DHCP/NDP\n"
" a zero value disables assignment\n"
" default: 65520: maximum 802.3 MTU minus 802.3 header\n"
" length, rounded to 32 bits (IPv4 words)\n"
" -a, --address ADDR Assign IPv4 or IPv6 address ADDR\n"
" can be specified zero to two times (for IPv4 and IPv6)\n"
" default: use addresses from interface with default route\n"
" -n, --netmask MASK Assign IPv4 MASK, dot-decimal or bits\n"
" default: netmask from matching address on the host\n"
" -M, --mac-addr ADDR Use source MAC address ADDR\n"
" default: 9a:55:9a:55:9a:55 (locally administered)\n"
" -g, --gateway ADDR Pass IPv4 or IPv6 address as gateway\n"
" default: gateway from interface with default route\n"
" -i, --interface NAME Interface for addresses and routes\n"
" default: from --outbound-if4 and --outbound-if6, if any\n"
" otherwise interface with first default route\n"
" -o, --outbound ADDR Bind to address as outbound source\n"
" can be specified zero to two times (for IPv4 and IPv6)\n"
" default: use source address from routing tables\n"
" --outbound-if4 NAME Bind to outbound interface for IPv4\n"
" default: use interface from default route\n"
" --outbound-if6 NAME Bind to outbound interface for IPv6\n"
" default: use interface from default route\n"
" -D, --dns ADDR Use IPv4 or IPv6 address as DNS\n"
" can be specified multiple times\n"
" a single, empty option disables DNS information\n");
if (strstr(name, "pasta"))
FPRINTF(f, " default: don't use any addresses\n");
else
FPRINTF(f, " default: use addresses from /etc/resolv.conf\n");
FPRINTF(f,
" -S, --search LIST Space-separated list, search domains\n"
" a single, empty option disables the DNS search list\n");
if (strstr(name, "pasta"))
FPRINTF(f, " default: don't use any search list\n");
else
FPRINTF(f, " default: use search list from /etc/resolv.conf\n");
if (strstr(name, "pasta"))
FPRINTF(f, " --dhcp-dns \tPass DNS list via DHCP/DHCPv6/NDP\n");
else
FPRINTF(f, " --no-dhcp-dns No DNS list in DHCP/DHCPv6/NDP\n");
if (strstr(name, "pasta"))
FPRINTF(f, " --dhcp-search Pass list via DHCP/DHCPv6/NDP\n");
else
FPRINTF(f, " --no-dhcp-search No list in DHCP/DHCPv6/NDP\n");
FPRINTF(f,
" --map-host-loopback ADDR Translate ADDR to refer to host\n"
" can be specified zero to two times (for IPv4 and IPv6)\n"
" default: gateway address\n"
" --map-guest-addr ADDR Translate ADDR to guest's address\n"
" can be specified zero to two times (for IPv4 and IPv6)\n"
" default: none\n"
" --dns-forward ADDR Forward DNS queries sent to ADDR\n"
" can be specified zero to two times (for IPv4 and IPv6)\n"
" default: don't forward DNS queries\n"
" --dns-host ADDR Host nameserver to direct queries to\n"
" can be specified zero to two times (for IPv4 and IPv6)\n"
" default: first nameserver from host's /etc/resolv.conf\n"
" --no-tcp Disable TCP protocol handler\n"
" --no-udp Disable UDP protocol handler\n"
" --no-icmp Disable ICMP/ICMPv6 protocol handler\n"
" --no-dhcp Disable DHCP server\n"
" --no-ndp Disable NDP responses\n"
" --no-dhcpv6 Disable DHCPv6 server\n"
" --no-ra Disable router advertisements\n"
" --freebind Bind to any address for forwarding\n"
" --no-map-gw Don't map gateway address to host\n"
" -4, --ipv4-only Enable IPv4 operation only\n"
" -6, --ipv6-only Enable IPv6 operation only\n");
if (strstr(name, "pasta"))
goto pasta_opts;
FPRINTF(f,
" -1, --one-off Quit after handling one single client\n"
" -t, --tcp-ports SPEC TCP port forwarding to guest\n"
" can be specified multiple times\n"
" SPEC can be:\n"
" 'none': don't forward any ports\n"
" 'all': forward all unbound, non-ephemeral ports\n"
" a comma-separated list, optionally ranged with '-'\n"
" and optional target ports after ':', with optional\n"
" address specification suffixed by '/' and optional\n"
" interface prefixed by '%%'. Ranges can be reduced by\n"
" excluding ports or ranges prefixed by '~'\n"
" Examples:\n"
" -t 22 Forward local port 22 to 22 on guest\n"
" -t 22:23 Forward local port 22 to 23 on guest\n"
" -t 22,25 Forward ports 22, 25 to ports 22, 25\n"
" -t 22-80 Forward ports 22 to 80\n"
" -t 22-80:32-90 Forward ports 22 to 80 to\n"
" corresponding port numbers plus 10\n"
" -t 192.0.2.1/5 Bind port 5 of 192.0.2.1 to guest\n"
" -t 5-25,~10-20 Forward ports 5 to 9, and 21 to 25\n"
" -t ~25 Forward all ports except for 25\n"
" default: none\n"
" -u, --udp-ports SPEC UDP port forwarding to guest\n"
" SPEC is as described for TCP above\n"
" default: none\n");
exit(status);
pasta_opts:
FPRINTF(f,
" -t, --tcp-ports SPEC TCP port forwarding to namespace\n"
" can be specified multiple times\n"
" SPEC can be:\n"
" 'none': don't forward any ports\n"
" 'auto': forward all ports currently bound in namespace\n"
" a comma-separated list, optionally ranged with '-'\n"
" and optional target ports after ':', with optional\n"
" address specification suffixed by '/' and optional\n"
" interface prefixed by '%%'. Examples:\n"
" -t 22 Forward local port 22 to port 22 in netns\n"
" -t 22:23 Forward local port 22 to port 23\n"
" -t 22,25 Forward ports 22, 25 to ports 22, 25\n"
" -t 22-80 Forward ports 22 to 80\n"
" -t 22-80:32-90 Forward ports 22 to 80 to\n"
" corresponding port numbers plus 10\n"
" -t 192.0.2.1/5 Bind port 5 of 192.0.2.1 to namespace\n"
" -t 5-25,~10-20 Forward ports 5 to 9, and 21 to 25\n"
" -t ~25 Forward all bound ports except for 25\n"
" default: auto\n"
" IPv6 bound ports are also forwarded for IPv4\n"
" -u, --udp-ports SPEC UDP port forwarding to namespace\n"
" SPEC is as described for TCP above\n"
" default: auto\n"
" IPv6 bound ports are also forwarded for IPv4\n"
" unless specified, with '-t auto', UDP ports with numbers\n"
" corresponding to forwarded TCP port numbers are\n"
" forwarded too\n"
" -T, --tcp-ns SPEC TCP port forwarding to init namespace\n"
" SPEC is as described above\n"
" default: auto\n"
" -U, --udp-ns SPEC UDP port forwarding to init namespace\n"
" SPEC is as described above\n"
" default: auto\n"
" --host-lo-to-ns-lo DEPRECATED:\n"
" Translate host-loopback forwards to\n"
" namespace loopback\n"
" --userns NSPATH Target user namespace to join\n"
" --netns PATH|NAME Target network namespace to join\n"
" --netns-only Don't join existing user namespace\n"
" implied if PATH or NAME are given without --userns\n"
" --no-netns-quit Don't quit if filesystem-bound target\n"
" network namespace is deleted\n"
" --config-net Configure tap interface in namespace\n"
" --no-copy-routes DEPRECATED:\n"
" Don't copy all routes to namespace\n"
" --no-copy-addrs DEPRECATED:\n"
" Don't copy all addresses to namespace\n"
" --ns-mac-addr ADDR Set MAC address on tap interface\n"
" --no-splice Disable inbound socket splicing\n");
exit(status);
}
/**
* conf_print() - Print fundamental configuration parameters
* @c: Execution context
*/
static void conf_print(const struct ctx *c)
{
char buf4[INET_ADDRSTRLEN], buf6[INET6_ADDRSTRLEN];
char bufmac[ETH_ADDRSTRLEN], ifn[IFNAMSIZ];
int i;
if (c->ifi4 > 0 || c->ifi6 > 0) {
info("Template interface: %s%s%s%s%s",
c->ifi4 > 0 ? if_indextoname(c->ifi4, ifn) : "",
c->ifi4 > 0 ? " (IPv4)" : "",
(c->ifi4 && c->ifi6) ? ", " : "",