1#include "common/netif.h"
2#include "common/io.h"
3
4#include <net/if.h>
5#include <net/if_dl.h>
6#include <net/route.h>
7#include <netinet/in.h>
8#include <sys/socket.h>
9
10#define ROUNDUP2(a, n) ((a) > 0 ? (1 + (((a) - 1U) | ((n) - 1))) : (n))
11
12#if __APPLE__
13 // https://github.com/apple-oss-distributions/network_cmds/blob/8f38231438e6a4d16ef8015e97e12c2c05105644/rtsol.tproj/if.c#L243
14 #define ROUNDUP(a) ROUNDUP2((a), sizeof(uint32_t))
15#elif __sun
16 // https://github.com/illumos/illumos-gate/blob/95b8c88950fa7b19af46bc63230137cf96b0bff7/usr/src/cmd/cmd-inet/usr.sbin/route.c#L339
17 #define ROUNDUP(a) ROUNDUP2((a), sizeof(long))
18#else
19 #error unknown platform
20#endif
21
22static struct sockaddr*
23get_rt_address(struct rt_msghdr* rtm, int desired) {
24 struct sockaddr* sa = (struct sockaddr*) (rtm + 1);
25
26 for (int i = 0; i < RTAX_MAX; i++) {
27 if (rtm->rtm_addrs & (1 << i)) {
28 if ((1 << i) == desired) {
29 return sa;
30 }
31
32#ifndef __sun
33 uint32_t salen = sa->sa_len;
34#else
35 uint32_t salen;
36 // https://github.com/illumos/illumos-gate/blob/95b8c88950fa7b19af46bc63230137cf96b0bff7/usr/src/cmd/cmd-inet/usr.sbin/route.c#L2941
37 switch (sa->sa_family) {
38 case AF_INET:
39 salen = sizeof(struct sockaddr_in);
40 break;
41 case AF_LINK:
42 salen = sizeof(struct sockaddr_dl);
43 break;
44 case AF_INET6:
45 salen = sizeof(struct sockaddr_in6);
46 break;
47 default:
48 salen = sizeof(struct sockaddr);
49 break;
50 }
51#endif
52 sa = (struct sockaddr*) (ROUNDUP(salen) + (char*) sa);
53 }
54 }
55 return nullptr;
56}
57
58bool ffNetifGetDefaultRouteImplV4(FFNetifDefaultRouteResult* result) {
59 // https://github.com/hashPirate/copenheimer-masscan-fork/blob/36f1ed9f7b751a7dccd5ed27874e2e703db7d481/src/rawsock-getif.c#L104
60
61 FF_AUTO_CLOSE_FD int pfRoute = socket(PF_ROUTE, SOCK_RAW, AF_INET);
62 if (pfRoute < 0) {
63 return false;
64 }
65
66 {
67 struct timeval timeout = { 1, 0 };
68 setsockopt(pfRoute, SOL_SOCKET, SO_RCVTIMEO, (char*) &timeout, sizeof(timeout));
69 setsockopt(pfRoute, SOL_SOCKET, SO_SNDTIMEO, (char*) &timeout, sizeof(timeout));
70 }
71
72 uint32_t pid = instance.state.platform.pid;
73
74 struct {
75 struct rt_msghdr hdr;
76 struct sockaddr_in dst;
77 uint8_t data[512];
78 } rtmsg = {
79 .hdr = {
80 .rtm_type = RTM_GET,
81 .rtm_flags = RTF_UP | RTF_GATEWAY,
82 .rtm_version = RTM_VERSION,
83 .rtm_addrs = RTA_DST | RTA_IFP | RTA_IFA,
84 .rtm_msglen = sizeof(rtmsg.hdr) + sizeof(rtmsg.dst),
85 .rtm_pid = (pid_t) pid,
86 .rtm_seq = 1,
87 },
88 .dst = {
89 .sin_family = AF_INET,
90#ifndef __sun
91 .sin_len = sizeof(rtmsg.dst),
92#endif
93 },
94 };
95
96 if (send(pfRoute, &rtmsg, rtmsg.hdr.rtm_msglen, 0) != rtmsg.hdr.rtm_msglen) {
97 return false;
98 }
99
100 bool gotResponse = false;
101 while (recv(pfRoute, &rtmsg, sizeof(rtmsg), 0) > 0) {
102 if (rtmsg.hdr.rtm_seq == 1 && rtmsg.hdr.rtm_pid == (pid_t) pid) {
103 gotResponse = true;
104 break;
105 }
106 }
107 if (!gotResponse) {
108 return false;
109 }
110
111#ifndef __sun // On Solaris, the RTF_GATEWAY flag is not set for default routes for some reason
112 if ((rtmsg.hdr.rtm_flags & (RTF_UP | RTF_GATEWAY)) == (RTF_UP | RTF_GATEWAY))
113#endif
114 {
115 struct sockaddr_dl* sdl = (struct sockaddr_dl*) get_rt_address(&rtmsg.hdr, RTA_IFP);
116 if (sdl
117#ifndef __sun
118 && sdl->sdl_len
119#endif
120 && sdl->sdl_family == AF_LINK) {
121 if (sdl->sdl_nlen > IF_NAMESIZE) {
122 return false;
123 }
124 memcpy(result->ifName, sdl->sdl_data, sdl->sdl_nlen);
125 result->ifName[sdl->sdl_nlen] = '\0';
126 result->ifIndex = sdl->sdl_index;
127
128 // Get the preferred source address
129 struct sockaddr_in* src = (struct sockaddr_in*) get_rt_address(&rtmsg.hdr, RTA_IFA);
130 if (src && src->sin_family == AF_INET) {
131 result->preferredSourceAddrV4 = src->sin_addr.s_addr;
132 }
133
134 return true;
135 }
136 return false;
137 }
138
139 return false;
140}
141
142bool ffNetifGetDefaultRouteImplV6(FFNetifDefaultRouteResult* result) {
143 // https://github.com/hashPirate/copenheimer-masscan-fork/blob/36f1ed9f7b751a7dccd5ed27874e2e703db7d481/src/rawsock-getif.c#L104
144
145 FF_AUTO_CLOSE_FD int pfRoute = socket(PF_ROUTE, SOCK_RAW, AF_INET6);
146 if (pfRoute < 0) {
147 return false;
148 }
149
150 {
151 struct timeval timeout = { 1, 0 };
152 setsockopt(pfRoute, SOL_SOCKET, SO_RCVTIMEO, (char*) &timeout, sizeof(timeout));
153 setsockopt(pfRoute, SOL_SOCKET, SO_SNDTIMEO, (char*) &timeout, sizeof(timeout));
154 }
155
156 uint32_t pid = instance.state.platform.pid;
157
158 struct {
159 struct rt_msghdr hdr;
160 struct sockaddr_in6 dst;
161 uint8_t data[512];
162 } rtmsg = {
163 .hdr = {
164 .rtm_type = RTM_GET,
165 .rtm_flags = RTF_UP | RTF_GATEWAY,
166 .rtm_version = RTM_VERSION,
167 .rtm_addrs = RTA_DST | RTA_IFP,
168 .rtm_msglen = sizeof(rtmsg.hdr) + sizeof(rtmsg.dst),
169 .rtm_pid = (pid_t) pid,
170 .rtm_seq = 2,
171 },
172 .dst = {
173 .sin6_family = AF_INET6,
174#ifndef __sun
175 .sin6_len = sizeof(rtmsg.dst),
176#endif
177 },
178 };
179
180 if (send(pfRoute, &rtmsg, rtmsg.hdr.rtm_msglen, 0) != rtmsg.hdr.rtm_msglen) {
181 return false;
182 }
183
184 bool gotResponse = false;
185 while (recv(pfRoute, &rtmsg, sizeof(rtmsg), 0) > 0) {
186 if (rtmsg.hdr.rtm_seq == 2 && rtmsg.hdr.rtm_pid == (pid_t) pid) {
187 gotResponse = true;
188 break;
189 }
190 }
191 if (!gotResponse) {
192 return false;
193 }
194
195#ifndef __sun // On Solaris, the RTF_GATEWAY flag is not set for default routes for some reason
196 if ((rtmsg.hdr.rtm_flags & (RTF_UP | RTF_GATEWAY)) == (RTF_UP | RTF_GATEWAY))
197#endif
198 {
199 struct sockaddr_dl* sdl = (struct sockaddr_dl*) get_rt_address(&rtmsg.hdr, RTA_IFP);
200 if (sdl
201#ifndef __sun
202 && sdl->sdl_len
203#endif
204 && sdl->sdl_family == AF_LINK) {
205 if (sdl->sdl_nlen > IF_NAMESIZE) {
206 return false;
207 }
208 memcpy(result->ifName, sdl->sdl_data, sdl->sdl_nlen);
209 result->ifName[sdl->sdl_nlen] = '\0';
210 result->ifIndex = sdl->sdl_index;
211
212 return true;
213 }
214 return false;
215 }
216
217 return false;
218}