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      1 /*
      2  * dhcpcd - DHCP client daemon
      3  * SPDX-License-Identifier: BSD-2-Clause
      4  * Copyright (c) 2006-2025 Roy Marples <roy (at) marples.name>
      5  * All rights reserved
      6 
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 
     29 #ifndef INTERFACE_H
     30 #define INTERFACE_H
     31 
     32 #include <net/if.h>
     33 #include <net/route.h> /* for RTM_ADD et all */
     34 #include <netinet/in.h>
     35 #ifdef BSD
     36 #include <netinet/in_var.h> /* for IN_IFF_TENTATIVE et all */
     37 #endif
     38 
     39 #include <ifaddrs.h>
     40 
     41 /* If the interface does not support carrier status (ie PPP),
     42  * dhcpcd can poll it for the relevant flags periodically */
     43 #define IF_POLL_UP 100 /* milliseconds */
     44 
     45 /*
     46  * Systems which handle 1 address per alias.
     47  * Currenly this is just Solaris.
     48  * While Linux can do aliased addresses, it is only useful for their
     49  * legacy ifconfig(8) tool which cannot display >1 IPv4 address
     50  * (it can display many IPv6 addresses which makes the limitation odd).
     51  * Linux has ip(8) which is a more feature rich tool, without the above
     52  * restriction.
     53  */
     54 #ifndef ALIAS_ADDR
     55 #ifdef __sun
     56 #define ALIAS_ADDR
     57 #endif
     58 #endif
     59 
     60 #include "config.h"
     61 
     62 /* POSIX defines ioctl request as an int, which Solaris and musl use.
     63  * Everyone else use an unsigned long, which happens to be the bigger one
     64  * so we use that in our on wire API. */
     65 #ifdef IOCTL_REQUEST_TYPE
     66 typedef IOCTL_REQUEST_TYPE ioctl_request_t;
     67 #else
     68 typedef unsigned long ioctl_request_t;
     69 #endif
     70 
     71 #include "dhcpcd.h"
     72 #include "ipv4.h"
     73 #include "ipv6.h"
     74 #include "route.h"
     75 
     76 #define EUI64_ADDR_LEN	    8
     77 #define INFINIBAND_ADDR_LEN 20
     78 
     79 /* Linux 2.4 doesn't define this */
     80 #ifndef ARPHRD_IEEE1394
     81 #define ARPHRD_IEEE1394 24
     82 #endif
     83 
     84 /* The BSD's don't define this yet */
     85 #ifndef ARPHRD_INFINIBAND
     86 #define ARPHRD_INFINIBAND 32
     87 #endif
     88 
     89 /* Maximum frame length.
     90  * Support jumbo frames and some extra. */
     91 #define FRAMEHDRLEN_MAX 14 /* only ethernet support */
     92 #define FRAMELEN_MAX	(FRAMEHDRLEN_MAX + 9216)
     93 
     94 #define UDPLEN_MAX	64 * 1024
     95 
     96 /* Work out if we have a private address or not
     97  * 10/8
     98  * 172.16/12
     99  * 192.168/16
    100  */
    101 #ifndef IN_PRIVATE
    102 #define IN_PRIVATE(addr)                           \
    103 	(((addr & IN_CLASSA_NET) == 0x0a000000) || \
    104 	    ((addr & 0xfff00000) == 0xac100000) || \
    105 	    ((addr & IN_CLASSB_NET) == 0xc0a80000))
    106 #endif
    107 
    108 #ifndef CLLADDR
    109 #ifdef AF_LINK
    110 #define CLLADDR(sdl) (const void *)((sdl)->sdl_data + (sdl)->sdl_nlen)
    111 #endif
    112 #endif
    113 
    114 #ifdef __sun
    115 /* Solaris stupidly defines this for compat with BSD
    116  * but then ignores it. */
    117 #undef RTF_CLONING
    118 
    119 /* This interface is busted on DilOS at least.
    120  * It used to work, but lukily Solaris can fall back to
    121  * IP_PKTINFO. */
    122 #undef IP_RECVIF
    123 #endif
    124 
    125 /* Private structures specific to an OS */
    126 #ifdef BSD
    127 struct priv {
    128 #ifdef INET6
    129 	int pf_inet6_fd;
    130 #endif
    131 #if (defined(SIOCALIFADDR) && defined(IFLR_ACTIVE)) || defined(SIOCGIFSTATUS)
    132 	int pf_link_fd;
    133 #endif
    134 };
    135 #endif
    136 #ifdef __linux__
    137 struct priv {
    138 	int route_fd;
    139 	int generic_fd;
    140 	uint32_t route_pid;
    141 };
    142 #endif
    143 #ifdef __sun
    144 struct priv {
    145 #ifdef INET6
    146 	int pf_inet6_fd;
    147 #endif
    148 };
    149 #endif
    150 
    151 #ifdef __sun
    152 /* Solaris getifaddrs is very un-suitable for dhcpcd.
    153  * See if-sun.c for details why. */
    154 struct ifaddrs;
    155 int if_getifaddrs(struct ifaddrs **);
    156 #define getifaddrs if_getifaddrs
    157 int if_getsubnet(struct dhcpcd_ctx *, const char *, int, void *, size_t);
    158 #endif
    159 
    160 int if_ioctl(struct dhcpcd_ctx *, ioctl_request_t, void *, size_t);
    161 #ifdef HAVE_PLEDGE
    162 #define pioctl(ctx, req, data, len) if_ioctl((ctx), (req), (data), (len))
    163 #else
    164 #define pioctl(ctx, req, data, len) \
    165 	ioctl((ctx)->pf_inet_fd, (req), (data), (len))
    166 #endif
    167 int if_setflag(struct interface *, short, short);
    168 int if_getmtu(const struct interface *);
    169 #define if_up(ifp)   if_setflag((ifp), (IFF_UP | IFF_RUNNING), 0)
    170 #define if_down(ifp) if_setflag((ifp), 0, IFF_UP);
    171 bool if_is_link_up(const struct interface *);
    172 bool if_valid_hwaddr(const uint8_t *, size_t);
    173 struct if_head *if_discover(struct dhcpcd_ctx *, struct ifaddrs **, int,
    174     char *const *);
    175 void if_freeifaddrs(struct dhcpcd_ctx *ctx, struct ifaddrs **);
    176 void if_markaddrsstale(struct if_head *);
    177 void if_learnaddrs(struct dhcpcd_ctx *, struct if_head *, struct ifaddrs **);
    178 void if_deletestaleaddrs(struct if_head *);
    179 struct interface *if_find(struct if_head *, const char *);
    180 struct interface *if_findindex(struct if_head *, unsigned int);
    181 struct interface *if_loopback(struct dhcpcd_ctx *);
    182 void if_free(struct interface *);
    183 int if_carrier(struct interface *, const void *);
    184 bool if_roaming(struct interface *);
    185 
    186 #ifdef ALIAS_ADDR
    187 int if_makealias(char *, size_t, const char *, int);
    188 #endif
    189 
    190 int if_mtu_os(const struct interface *);
    191 
    192 /*
    193  * Helper to decode an interface name of bge0:1 to
    194  * devname = bge0, drvname = bge0, ppa = 0, lun = 1.
    195  * If ppa or lun are invalid they are set to -1.
    196  */
    197 struct if_spec {
    198 	char ifname[IF_NAMESIZE];
    199 	char devname[IF_NAMESIZE];
    200 	char drvname[IF_NAMESIZE];
    201 	int ppa;
    202 	int vlid;
    203 	int lun;
    204 };
    205 int if_nametospec(const char *, struct if_spec *);
    206 
    207 /* The below functions are provided by if-KERNEL.c */
    208 int os_init(void);
    209 int if_init(struct interface *);    /* init interface from kernel */
    210 int if_init_os(struct interface *); /* init kernel from interface */
    211 int if_conf(struct interface *);    /* finish configuration from kernel */
    212 int if_getssid(struct interface *);
    213 int if_ignoregroup(int, const char *);
    214 bool if_ignore(struct dhcpcd_ctx *, const char *);
    215 int if_vimaster(struct dhcpcd_ctx *ctx, const char *);
    216 unsigned short if_vlanid(const struct interface *);
    217 char *if_getnetworknamespace(char *, size_t); /* used by udev */
    218 int if_opensockets(struct dhcpcd_ctx *);
    219 int if_opensockets_os(struct dhcpcd_ctx *);
    220 void if_closesockets(struct dhcpcd_ctx *);
    221 void if_closesockets_os(struct dhcpcd_ctx *);
    222 int if_handlelink(struct dhcpcd_ctx *);
    223 int if_randomisemac(struct interface *);
    224 int if_setmac(struct interface *ifp, void *, uint8_t);
    225 
    226 /* dhcpcd uses the same routing flags as BSD.
    227  * If the platform doesn't use these flags,
    228  * map them in the platform interace file. */
    229 #ifndef RTM_ADD
    230 #define RTM_ADD	   0x1 /* Add Route */
    231 #define RTM_DELETE 0x2 /* Delete Route */
    232 #define RTM_CHANGE 0x3 /* Change Metrics or flags */
    233 #define RTM_GET	   0x4 /* Report Metrics */
    234 #endif
    235 
    236 /* Define SOCK_CLOEXEC and SOCK_NONBLOCK for systems that lack it.
    237  * xsocket() in if.c will map them to fctnl FD_CLOEXEC and O_NONBLOCK. */
    238 #ifdef SOCK_CLOEXEC
    239 #define HAVE_SOCK_CLOEXEC
    240 #else
    241 #define SOCK_CLOEXEC 0x10000000
    242 #endif
    243 #ifdef SOCK_NONBLOCK
    244 #define HAVE_SOCK_NONBLOCK
    245 #else
    246 #define SOCK_NONBLOCK 0x20000000
    247 #endif
    248 #ifndef SOCK_CXNB
    249 #define SOCK_CXNB SOCK_CLOEXEC | SOCK_NONBLOCK
    250 #endif
    251 int xsocket(int, int, int);
    252 int xsocketpair(int, int, int, int[2]);
    253 
    254 int if_route(unsigned char, const struct rt *rt);
    255 int if_initrt(struct dhcpcd_ctx *, rb_tree_t *, int);
    256 
    257 int if_missfilter(struct interface *, struct sockaddr *);
    258 int if_missfilter_apply(struct dhcpcd_ctx *);
    259 
    260 #ifdef INET
    261 int if_address(unsigned char, const struct ipv4_addr *);
    262 int if_addrflags(const struct interface *, const struct in_addr *,
    263     const char *);
    264 
    265 #endif
    266 
    267 #ifdef INET6
    268 void if_disable_rtadv(void);
    269 void if_setup_inet6(const struct interface *);
    270 int ip6_forwarding(const char *ifname);
    271 
    272 struct ra;
    273 struct ipv6_addr;
    274 
    275 int if_applyra(const struct ra *);
    276 int if_address6(unsigned char, const struct ipv6_addr *);
    277 int if_addrflags6(const struct interface *, const struct in6_addr *,
    278     const char *);
    279 int if_getlifetime6(struct ipv6_addr *);
    280 
    281 #else
    282 #define if_checkipv6(a, b, c) (-1)
    283 #endif
    284 
    285 int if_machinearch(char *, size_t);
    286 struct interface *if_findifpfromcmsg(struct dhcpcd_ctx *, struct msghdr *,
    287     int *);
    288 
    289 #ifdef __linux__
    290 int if_linksocket(struct sockaddr_nl *, int, int);
    291 int if_getnetlink(struct dhcpcd_ctx *, struct iovec *, int, int,
    292     int (*)(struct dhcpcd_ctx *, void *, struct nlmsghdr *), void *);
    293 #endif
    294 #endif
    295