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8
9#include "libbb.h"
10
11#if defined(IPV6_PKTINFO) && !defined(IPV6_RECVPKTINFO)
12# define IPV6_RECVPKTINFO IPV6_PKTINFO
13#endif
14
15
16
17
18
19void FAST_FUNC
20socket_want_pktinfo(int fd UNUSED_PARAM)
21{
22#ifdef IP_PKTINFO
23 setsockopt_1(fd, IPPROTO_IP, IP_PKTINFO);
24#endif
25#if ENABLE_FEATURE_IPV6 && defined(IPV6_RECVPKTINFO)
26 setsockopt_1(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO);
27#endif
28}
29
30
31ssize_t FAST_FUNC
32send_to_from(int fd, void *buf, size_t len, int flags,
33 const struct sockaddr *to,
34 const struct sockaddr *from,
35 socklen_t tolen)
36{
37#ifndef IP_PKTINFO
38 (void)from;
39 return sendto(fd, buf, len, flags, to, tolen);
40#else
41 struct iovec iov[1];
42 struct msghdr msg;
43 union {
44 char cmsg[CMSG_SPACE(sizeof(struct in_pktinfo))];
45# if ENABLE_FEATURE_IPV6 && defined(IPV6_PKTINFO)
46 char cmsg6[CMSG_SPACE(sizeof(struct in6_pktinfo))];
47# endif
48 } u;
49 struct cmsghdr* cmsgptr;
50
51 if (from->sa_family != AF_INET
52# if ENABLE_FEATURE_IPV6
53 && from->sa_family != AF_INET6
54# endif
55 ) {
56
57 return sendto(fd, buf, len, flags, to, tolen);
58 }
59
60
61
62 iov[0].iov_base = buf;
63 iov[0].iov_len = len;
64
65 memset(&u, 0, sizeof(u));
66
67 memset(&msg, 0, sizeof(msg));
68 msg.msg_name = (void *)(struct sockaddr *)to;
69 msg.msg_namelen = tolen;
70 msg.msg_iov = iov;
71 msg.msg_iovlen = 1;
72 msg.msg_control = &u;
73 msg.msg_controllen = sizeof(u);
74 msg.msg_flags = flags;
75
76 cmsgptr = CMSG_FIRSTHDR(&msg);
77
78
79
80
81
82
83 if ( from->sa_family == AF_INET) {
84 struct in_pktinfo *pktptr;
85 cmsgptr->cmsg_level = IPPROTO_IP;
86 cmsgptr->cmsg_type = IP_PKTINFO;
87 cmsgptr->cmsg_len = CMSG_LEN(sizeof(struct in_pktinfo));
88 pktptr = (struct in_pktinfo *)(CMSG_DATA(cmsgptr));
89
90
91
92
93
94
95
96 pktptr->ipi_spec_dst = ((struct sockaddr_in*)from)->sin_addr;
97 }
98# if ENABLE_FEATURE_IPV6 && defined(IPV6_PKTINFO)
99 else if ( from->sa_family == AF_INET6) {
100 struct in6_pktinfo *pktptr;
101 cmsgptr->cmsg_level = IPPROTO_IPV6;
102 cmsgptr->cmsg_type = IPV6_PKTINFO;
103 cmsgptr->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
104 pktptr = (struct in6_pktinfo *)(CMSG_DATA(cmsgptr));
105
106 pktptr->ipi6_addr = ((struct sockaddr_in6*)from)->sin6_addr;
107 }
108# endif
109 msg.msg_controllen = cmsgptr->cmsg_len;
110
111 return sendmsg(fd, &msg, flags);
112#endif
113}
114
115
116
117
118
119ssize_t FAST_FUNC
120recv_from_to(int fd, void *buf, size_t len, int flags,
121 struct sockaddr *from, struct sockaddr *to,
122 socklen_t sa_size)
123{
124#ifndef IP_PKTINFO
125 (void)to;
126 return recvfrom(fd, buf, len, flags, from, &sa_size);
127#else
128
129 struct iovec iov[1];
130 union {
131 char cmsg[CMSG_SPACE(sizeof(struct in_pktinfo))];
132# if ENABLE_FEATURE_IPV6 && defined(IPV6_PKTINFO)
133 char cmsg6[CMSG_SPACE(sizeof(struct in6_pktinfo))];
134# endif
135 } u;
136 struct cmsghdr *cmsgptr;
137 struct msghdr msg;
138 ssize_t recv_length;
139
140 iov[0].iov_base = buf;
141 iov[0].iov_len = len;
142
143 memset(&msg, 0, sizeof(msg));
144 msg.msg_name = (struct sockaddr *)from;
145 msg.msg_namelen = sa_size;
146 msg.msg_iov = iov;
147 msg.msg_iovlen = 1;
148 msg.msg_control = &u;
149 msg.msg_controllen = sizeof(u);
150
151 recv_length = recvmsg(fd, &msg, flags);
152 if (recv_length < 0)
153 return recv_length;
154
155# define to4 ((struct sockaddr_in*)to)
156# define to6 ((struct sockaddr_in6*)to)
157
158 for (cmsgptr = CMSG_FIRSTHDR(&msg);
159 cmsgptr != NULL;
160 cmsgptr = CMSG_NXTHDR(&msg, cmsgptr)
161 ) {
162 if (cmsgptr->cmsg_level == IPPROTO_IP
163 && cmsgptr->cmsg_type == IP_PKTINFO
164 ) {
165 const int IPI_ADDR_OFF = offsetof(struct in_pktinfo, ipi_addr);
166 to->sa_family = AF_INET;
167
168
169 memcpy(&to4->sin_addr, (char*)(CMSG_DATA(cmsgptr)) + IPI_ADDR_OFF, sizeof(to4->sin_addr));
170
171 break;
172 }
173# if ENABLE_FEATURE_IPV6 && defined(IPV6_PKTINFO)
174 if (cmsgptr->cmsg_level == IPPROTO_IPV6
175 && cmsgptr->cmsg_type == IPV6_PKTINFO
176 ) {
177 const int IPI6_ADDR_OFF = offsetof(struct in6_pktinfo, ipi6_addr);
178 to->sa_family = AF_INET6;
179
180
181 memcpy(&to6->sin6_addr, (char*)(CMSG_DATA(cmsgptr)) + IPI6_ADDR_OFF, sizeof(to6->sin6_addr));
182
183 break;
184 }
185# endif
186 }
187 return recv_length;
188#endif
189}
190