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[thirdparty/systemd.git] / src / basic / socket-util.h
1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
2 #pragma once
3
4 #include <linux/if_ether.h>
5 #include <linux/if_infiniband.h>
6 #include <linux/if_packet.h>
7 #include <linux/netlink.h>
8 #include <linux/vm_sockets.h>
9 #include <netinet/in.h>
10 #include <sys/socket.h>
11 #include <sys/un.h>
12
13 #include "forward.h"
14 #include "memory-util.h"
15 #include "missing_network.h"
16
17 union sockaddr_union {
18 /* The minimal, abstract version */
19 struct sockaddr sa;
20
21 /* The libc provided version that allocates "enough room" for every protocol */
22 struct sockaddr_storage storage;
23
24 /* Protocol-specific implementations */
25 struct sockaddr_in in;
26 struct sockaddr_in6 in6;
27 struct sockaddr_un un;
28 struct sockaddr_nl nl;
29 struct sockaddr_ll ll;
30 struct sockaddr_vm vm;
31
32 /* Ensure there is enough space to store Infiniband addresses */
33 uint8_t ll_buffer[offsetof(struct sockaddr_ll, sll_addr) + CONST_MAX(ETH_ALEN, INFINIBAND_ALEN)];
34
35 /* Ensure there is enough space after the AF_UNIX sun_path for one more NUL byte, just to be sure that the path
36 * component is always followed by at least one NUL byte. */
37 uint8_t un_buffer[sizeof(struct sockaddr_un) + 1];
38 };
39
40 #define SUN_PATH_LEN (sizeof(((struct sockaddr_un){}).sun_path))
41
42 typedef struct SocketAddress {
43 union sockaddr_union sockaddr;
44
45 /* We store the size here explicitly due to the weird
46 * sockaddr_un semantics for abstract sockets */
47 socklen_t size;
48
49 /* Socket type, i.e. SOCK_STREAM, SOCK_DGRAM, ... */
50 int type;
51
52 /* Socket protocol, IPPROTO_xxx, usually 0, except for netlink */
53 int protocol;
54 } SocketAddress;
55
56 typedef enum SocketAddressBindIPv6Only {
57 SOCKET_ADDRESS_DEFAULT,
58 SOCKET_ADDRESS_BOTH,
59 SOCKET_ADDRESS_IPV6_ONLY,
60 _SOCKET_ADDRESS_BIND_IPV6_ONLY_MAX,
61 _SOCKET_ADDRESS_BIND_IPV6_ONLY_INVALID = -EINVAL,
62 } SocketAddressBindIPv6Only;
63
64 #define socket_address_family(a) ((a)->sockaddr.sa.sa_family)
65
66 const char* socket_address_type_to_string(int t) _const_;
67 int socket_address_type_from_string(const char *s) _pure_;
68
69 int sockaddr_un_unlink(const struct sockaddr_un *sa);
70
71 static inline int socket_address_unlink(const SocketAddress *a) {
72 return socket_address_family(a) == AF_UNIX ? sockaddr_un_unlink(&a->sockaddr.un) : 0;
73 }
74
75 bool socket_address_can_accept(const SocketAddress *a) _pure_;
76
77 int socket_address_listen(
78 const SocketAddress *a,
79 int flags,
80 int backlog,
81 SocketAddressBindIPv6Only only,
82 const char *bind_to_device,
83 bool reuse_port,
84 bool free_bind,
85 bool transparent,
86 mode_t directory_mode,
87 mode_t socket_mode,
88 const char *label);
89
90 int socket_address_verify(const SocketAddress *a, bool strict) _pure_;
91 int socket_address_print(const SocketAddress *a, char **p);
92 bool socket_address_matches_fd(const SocketAddress *a, int fd);
93
94 bool socket_address_equal(const SocketAddress *a, const SocketAddress *b) _pure_;
95
96 const char* socket_address_get_path(const SocketAddress *a);
97
98 bool socket_ipv6_is_supported(void);
99 bool socket_ipv6_is_enabled(void);
100
101 int sockaddr_port(const struct sockaddr *_sa, unsigned *port);
102 const union in_addr_union *sockaddr_in_addr(const struct sockaddr *sa);
103 int sockaddr_set_in_addr(union sockaddr_union *u, int family, const union in_addr_union *a, uint16_t port);
104
105 int sockaddr_pretty(const struct sockaddr *_sa, socklen_t salen, bool translate_ipv6, bool include_port, char **ret);
106 int getpeername_pretty(int fd, bool include_port, char **ret);
107 int getsockname_pretty(int fd, char **ret);
108
109 int socknameinfo_pretty(const struct sockaddr *sa, socklen_t salen, char **_ret);
110
111 const char* socket_address_bind_ipv6_only_to_string(SocketAddressBindIPv6Only b) _const_;
112 SocketAddressBindIPv6Only socket_address_bind_ipv6_only_from_string(const char *s) _pure_;
113 SocketAddressBindIPv6Only socket_address_bind_ipv6_only_or_bool_from_string(const char *s);
114
115 int netlink_family_to_string_alloc(int b, char **s);
116 int netlink_family_from_string(const char *s) _pure_;
117
118 bool sockaddr_equal(const union sockaddr_union *a, const union sockaddr_union *b);
119
120 int fd_set_sndbuf(int fd, size_t n, bool increase);
121 static inline int fd_inc_sndbuf(int fd, size_t n) {
122 return fd_set_sndbuf(fd, n, true);
123 }
124 int fd_set_rcvbuf(int fd, size_t n, bool increase);
125 static inline int fd_increase_rxbuf(int fd, size_t n) {
126 return fd_set_rcvbuf(fd, n, true);
127 }
128
129 int ip_tos_to_string_alloc(int i, char **s);
130 int ip_tos_from_string(const char *s);
131
132 typedef enum {
133 IFNAME_VALID_ALTERNATIVE = 1 << 0, /* Allow "altnames" too */
134 IFNAME_VALID_NUMERIC = 1 << 1, /* Allow decimal formatted ifindexes too */
135 IFNAME_VALID_SPECIAL = 1 << 2, /* Allow the special names "all" and "default" */
136 _IFNAME_VALID_ALL = IFNAME_VALID_ALTERNATIVE | IFNAME_VALID_NUMERIC | IFNAME_VALID_SPECIAL,
137 } IfnameValidFlags;
138 bool ifname_valid_char(char a) _const_;
139 bool ifname_valid_full(const char *p, IfnameValidFlags flags) _pure_;
140 static inline bool ifname_valid(const char *p) {
141 return ifname_valid_full(p, 0);
142 }
143 bool address_label_valid(const char *p) _pure_;
144
145 int getpeercred(int fd, struct ucred *ucred);
146 int getpeersec(int fd, char **ret);
147 int getpeergroups(int fd, gid_t **ret);
148 int getpeerpidfd(int fd);
149 int getpeerpidref(int fd, PidRef *ret);
150
151 ssize_t send_many_fds_iov_sa(
152 int transport_fd,
153 int *fds_array, size_t n_fds_array,
154 const struct iovec *iov, size_t iovlen,
155 const struct sockaddr *sa, socklen_t len,
156 int flags);
157 static inline ssize_t send_many_fds_iov(
158 int transport_fd,
159 int *fds_array, size_t n_fds_array,
160 const struct iovec *iov, size_t iovlen,
161 int flags) {
162
163 return send_many_fds_iov_sa(transport_fd, fds_array, n_fds_array, iov, iovlen, NULL, 0, flags);
164 }
165 static inline int send_many_fds(
166 int transport_fd,
167 int *fds_array,
168 size_t n_fds_array,
169 int flags) {
170
171 return send_many_fds_iov_sa(transport_fd, fds_array, n_fds_array, NULL, 0, NULL, 0, flags);
172 }
173 ssize_t send_one_fd_iov_sa(
174 int transport_fd,
175 int fd,
176 const struct iovec *iov, size_t iovlen,
177 const struct sockaddr *sa, socklen_t len,
178 int flags);
179 int send_one_fd_sa(int transport_fd,
180 int fd,
181 const struct sockaddr *sa, socklen_t len,
182 int flags);
183 #define send_one_fd_iov(transport_fd, fd, iov, iovlen, flags) send_one_fd_iov_sa(transport_fd, fd, iov, iovlen, NULL, 0, flags)
184 #define send_one_fd(transport_fd, fd, flags) send_one_fd_iov_sa(transport_fd, fd, NULL, 0, NULL, 0, flags)
185 ssize_t receive_one_fd_iov(int transport_fd, struct iovec *iov, size_t iovlen, int flags, int *ret_fd);
186 int receive_one_fd(int transport_fd, int flags);
187 ssize_t receive_many_fds_iov(int transport_fd, struct iovec *iov, size_t iovlen, int **ret_fds_array, size_t *ret_n_fds_array, int flags);
188 int receive_many_fds(int transport_fd, int **ret_fds_array, size_t *ret_n_fds_array, int flags);
189
190 ssize_t next_datagram_size_fd(int fd);
191
192 int flush_accept(int fd);
193 ssize_t flush_mqueue(int fd);
194
195 #define CMSG_FOREACH(cmsg, mh) \
196 for ((cmsg) = CMSG_FIRSTHDR(mh); (cmsg); (cmsg) = CMSG_NXTHDR((mh), (cmsg)))
197
198 /* Returns the cmsghdr's data pointer, but safely cast to the specified type. Does two alignment checks: one
199 * at compile time, that the requested type has a smaller or same alignment as 'struct cmsghdr', and one
200 * during runtime, that the actual pointer matches the alignment too. This is supposed to catch cases such as
201 * 'struct timeval' is embedded into 'struct cmsghdr' on architectures where the alignment of the former is 8
202 * bytes (because of a 64-bit time_t), but of the latter is 4 bytes (because size_t is 32 bits), such as
203 * riscv32. */
204 #define CMSG_TYPED_DATA(cmsg, type) \
205 ({ \
206 struct cmsghdr *_cmsg = (cmsg); \
207 assert_cc(alignof(type) <= alignof(struct cmsghdr)); \
208 _cmsg ? CAST_ALIGN_PTR(type, CMSG_DATA(_cmsg)) : (type*) NULL; \
209 })
210
211 struct cmsghdr* cmsg_find(struct msghdr *mh, int level, int type, socklen_t length);
212 void* cmsg_find_and_copy_data(struct msghdr *mh, int level, int type, void *buf, size_t buf_len);
213
214 /* Type-safe, dereferencing version of cmsg_find() */
215 #define CMSG_FIND_DATA(mh, level, type, ctype) \
216 CMSG_TYPED_DATA(cmsg_find(mh, level, type, CMSG_LEN(sizeof(ctype))), ctype)
217
218 /* Type-safe version of cmsg_find_and_copy_data() */
219 #define CMSG_FIND_AND_COPY_DATA(mh, level, type, ctype) \
220 (ctype*) cmsg_find_and_copy_data(mh, level, type, &(ctype){}, sizeof(ctype))
221
222 /* Resolves to a type that can carry cmsghdr structures. Make sure things are properly aligned, i.e. the type
223 * itself is placed properly in memory and the size is also aligned to what's appropriate for "cmsghdr"
224 * structures. */
225 #define CMSG_BUFFER_TYPE(size) \
226 union { \
227 struct cmsghdr cmsghdr; \
228 uint8_t buf[size]; \
229 uint8_t align_check[(size) >= CMSG_SPACE(0) && \
230 (size) == CMSG_ALIGN(size) ? 1 : -1]; \
231 }
232
233 size_t sockaddr_ll_len(const struct sockaddr_ll *sa);
234
235 size_t sockaddr_un_len(const struct sockaddr_un *sa);
236
237 size_t sockaddr_len(const union sockaddr_union *sa);
238
239 int socket_ioctl_fd(void);
240
241 int sockaddr_un_set_path(struct sockaddr_un *ret, const char *path);
242
243 static inline int setsockopt_int(int fd, int level, int optname, int value) {
244 if (setsockopt(fd, level, optname, &value, sizeof(value)) < 0)
245 return -errno;
246
247 return 0;
248 }
249
250 int getsockopt_int(int fd, int level, int optname, int *ret);
251
252 int socket_bind_to_ifname(int fd, const char *ifname);
253 int socket_bind_to_ifindex(int fd, int ifindex);
254
255 int socket_autobind(int fd, char **ret_name);
256
257 /* Define a 64-bit version of timeval/timespec in any case, even on 32-bit userspace. */
258 struct timeval_large {
259 uint64_t tvl_sec, tvl_usec;
260 };
261 struct timespec_large {
262 uint64_t tvl_sec, tvl_nsec;
263 };
264
265 /* glibc duplicates timespec/timeval on certain 32-bit arches, once in 32-bit and once in 64-bit.
266 * See __convert_scm_timestamps() in glibc source code. Hence, we need additional buffer space for them
267 * to prevent truncating control msg (recvmsg() MSG_CTRUNC). */
268 #define CMSG_SPACE_TIMEVAL \
269 ((sizeof(struct timeval) == sizeof(struct timeval_large)) ? \
270 CMSG_SPACE(sizeof(struct timeval)) : \
271 CMSG_SPACE(sizeof(struct timeval)) + \
272 CMSG_SPACE(sizeof(struct timeval_large)))
273 #define CMSG_SPACE_TIMESPEC \
274 ((sizeof(struct timespec) == sizeof(struct timespec_large)) ? \
275 CMSG_SPACE(sizeof(struct timespec)) : \
276 CMSG_SPACE(sizeof(struct timespec)) + \
277 CMSG_SPACE(sizeof(struct timespec_large)))
278
279 ssize_t recvmsg_safe(int sockfd, struct msghdr *msg, int flags);
280
281 int socket_get_family(int fd);
282 int socket_set_recvpktinfo(int fd, int af, bool b);
283 int socket_set_unicast_if(int fd, int af, int ifi);
284
285 int socket_set_option(int fd, int af, int opt_ipv4, int opt_ipv6, int val);
286 static inline int socket_set_recverr(int fd, int af, bool b) {
287 return socket_set_option(fd, af, IP_RECVERR, IPV6_RECVERR, b);
288 }
289 static inline int socket_set_recvttl(int fd, int af, bool b) {
290 return socket_set_option(fd, af, IP_RECVTTL, IPV6_RECVHOPLIMIT, b);
291 }
292 static inline int socket_set_ttl(int fd, int af, int ttl) {
293 return socket_set_option(fd, af, IP_TTL, IPV6_UNICAST_HOPS, ttl);
294 }
295 static inline int socket_set_freebind(int fd, int af, bool b) {
296 return socket_set_option(fd, af, IP_FREEBIND, IPV6_FREEBIND, b);
297 }
298 static inline int socket_set_transparent(int fd, int af, bool b) {
299 return socket_set_option(fd, af, IP_TRANSPARENT, IPV6_TRANSPARENT, b);
300 }
301 static inline int socket_set_recvfragsize(int fd, int af, bool b) {
302 return socket_set_option(fd, af, IP_RECVFRAGSIZE, IPV6_RECVFRAGSIZE, b);
303 }
304
305 int socket_get_mtu(int fd, int af, size_t *ret);
306
307 /* an initializer for struct ucred that initialized all fields to the invalid value appropriate for each */
308 #define UCRED_INVALID { .pid = 0, .uid = UID_INVALID, .gid = GID_INVALID }
309
310 int connect_unix_path(int fd, int dir_fd, const char *path);
311
312 static inline bool VSOCK_CID_IS_REGULAR(unsigned cid) {
313 /* 0, 1, 2, UINT32_MAX are special, refuse those */
314 return cid > 2 && cid < UINT32_MAX;
315 }
316
317 int vsock_parse_port(const char *s, unsigned *ret);
318 int vsock_parse_cid(const char *s, unsigned *ret);
319
320 /* Parses AF_UNIX and AF_VSOCK addresses. AF_INET[6] require some netlink calls, so it cannot be in
321 * src/basic/ and is done from 'socket_local_address from src/shared/. Return -EPROTO in case of
322 * protocol mismatch. */
323 int socket_address_parse_unix(SocketAddress *ret_address, const char *s);
324 int socket_address_parse_vsock(SocketAddress *ret_address, const char *s);
325 int socket_address_equal_unix(const char *a, const char *b);
326
327 /* libc's SOMAXCONN is defined to 128 or 4096 (at least on glibc). But actually, the value can be much
328 * larger. In our codebase we want to set it to the max usually, since nowadays socket memory is properly
329 * tracked by memcg, and hence we don't need to enforce extra limits here. Moreover, the kernel caps it to
330 * /proc/sys/net/core/somaxconn anyway, thus by setting this to unbounded we just make that sysctl file
331 * authoritative. */
332 #define SOMAXCONN_DELUXE INT_MAX
333
334 int vsock_get_local_cid(unsigned *ret);
335
336 int netlink_socket_get_multicast_groups(int fd, size_t *ret_len, uint32_t **ret_groups);
337
338 int socket_get_cookie(int fd, uint64_t *ret);
339
340 void cmsg_close_all(struct msghdr *mh);