src/basic/socket-util.h

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 #pragma once
   3
   4 #include <inttypes.h>
   5 #include <linux/netlink.h>
   6 #include <linux/if_ether.h>
   7 #include <linux/if_infiniband.h>
   8 #include <linux/if_packet.h>
   9 #include <netinet/in.h>
  10 #include <stdbool.h>
  11 #include <stddef.h>
  12 #include <string.h>
  13 #include <sys/socket.h>
  14 #include <sys/types.h>
  15 #include <sys/un.h>
  16
  17 #include "errno-util.h"
  18 #include "in-addr-util.h"
  19 #include "macro.h"
  20 #include "missing_network.h"
  21 #include "missing_socket.h"
  22 #include "sparse-endian.h"
  23
  24 union sockaddr_union {
  25         /* The minimal, abstract version */
  26         struct sockaddr sa;
  27
  28         /* The libc provided version that allocates "enough room" for every protocol */
  29         struct sockaddr_storage storage;
  30
  31         /* Protoctol-specific implementations */
  32         struct sockaddr_in in;
  33         struct sockaddr_in6 in6;
  34         struct sockaddr_un un;
  35         struct sockaddr_nl nl;
  36         struct sockaddr_ll ll;
  37         struct sockaddr_vm vm;
  38
  39         /* Ensure there is enough space to store Infiniband addresses */
  40         uint8_t ll_buffer[offsetof(struct sockaddr_ll, sll_addr) + CONST_MAX(ETH_ALEN, INFINIBAND_ALEN)];
  41
  42         /* Ensure there is enough space after the AF_UNIX sun_path for one more NUL byte, just to be sure that the path
  43          * component is always followed by at least one NUL byte. */
  44         uint8_t un_buffer[sizeof(struct sockaddr_un) + 1];
  45 };
  46
  47 #define SUN_PATH_LEN (sizeof(((struct sockaddr_un){}).sun_path))
  48
  49 typedef struct SocketAddress {
  50         union sockaddr_union sockaddr;
  51
  52         /* We store the size here explicitly due to the weird
  53          * sockaddr_un semantics for abstract sockets */
  54         socklen_t size;
  55
  56         /* Socket type, i.e. SOCK_STREAM, SOCK_DGRAM, ... */
  57         int type;
  58
  59         /* Socket protocol, IPPROTO_xxx, usually 0, except for netlink */
  60         int protocol;
  61 } SocketAddress;
  62
  63 typedef enum SocketAddressBindIPv6Only {
  64         SOCKET_ADDRESS_DEFAULT,
  65         SOCKET_ADDRESS_BOTH,
  66         SOCKET_ADDRESS_IPV6_ONLY,
  67         _SOCKET_ADDRESS_BIND_IPV6_ONLY_MAX,
  68         _SOCKET_ADDRESS_BIND_IPV6_ONLY_INVALID = -EINVAL,
  69 } SocketAddressBindIPv6Only;
  70
  71 #define socket_address_family(a) ((a)->sockaddr.sa.sa_family)
  72
  73 const char* socket_address_type_to_string(int t) _const_;
  74 int socket_address_type_from_string(const char *s) _pure_;
  75
  76 int sockaddr_un_unlink(const struct sockaddr_un *sa);
  77
  78 static inline int socket_address_unlink(const SocketAddress *a) {
  79         return socket_address_family(a) == AF_UNIX ? sockaddr_un_unlink(&a->sockaddr.un) : 0;
  80 }
  81
  82 bool socket_address_can_accept(const SocketAddress *a) _pure_;
  83
  84 int socket_address_listen(
  85                 const SocketAddress *a,
  86                 int flags,
  87                 int backlog,
  88                 SocketAddressBindIPv6Only only,
  89                 const char *bind_to_device,
  90                 bool reuse_port,
  91                 bool free_bind,
  92                 bool transparent,
  93                 mode_t directory_mode,
  94                 mode_t socket_mode,
  95                 const char *label);
  96
  97 int socket_address_verify(const SocketAddress *a, bool strict) _pure_;
  98 int socket_address_print(const SocketAddress *a, char **p);
  99 bool socket_address_matches_fd(const SocketAddress *a, int fd);
 100
 101 bool socket_address_equal(const SocketAddress *a, const SocketAddress *b) _pure_;
 102
 103 const char* socket_address_get_path(const SocketAddress *a);
 104
 105 bool socket_ipv6_is_supported(void);
 106 bool socket_ipv6_is_enabled(void);
 107
 108 int sockaddr_port(const struct sockaddr *_sa, unsigned *port);
 109 const union in_addr_union *sockaddr_in_addr(const struct sockaddr *sa);
 110 int sockaddr_set_in_addr(union sockaddr_union *u, int family, const union in_addr_union *a, uint16_t port);
 111
 112 int sockaddr_pretty(const struct sockaddr *_sa, socklen_t salen, bool translate_ipv6, bool include_port, char **ret);
 113 int getpeername_pretty(int fd, bool include_port, char **ret);
 114 int getsockname_pretty(int fd, char **ret);
 115
 116 int socknameinfo_pretty(union sockaddr_union *sa, socklen_t salen, char **_ret);
 117
 118 const char* socket_address_bind_ipv6_only_to_string(SocketAddressBindIPv6Only b) _const_;
 119 SocketAddressBindIPv6Only socket_address_bind_ipv6_only_from_string(const char *s) _pure_;
 120 SocketAddressBindIPv6Only socket_address_bind_ipv6_only_or_bool_from_string(const char *s);
 121
 122 int netlink_family_to_string_alloc(int b, char **s);
 123 int netlink_family_from_string(const char *s) _pure_;
 124
 125 bool sockaddr_equal(const union sockaddr_union *a, const union sockaddr_union *b);
 126
 127 int fd_set_sndbuf(int fd, size_t n, bool increase);
 128 static inline int fd_inc_sndbuf(int fd, size_t n) {
 129         return fd_set_sndbuf(fd, n, true);
 130 }
 131 int fd_set_rcvbuf(int fd, size_t n, bool increase);
 132 static inline int fd_increase_rxbuf(int fd, size_t n) {
 133         return fd_set_rcvbuf(fd, n, true);
 134 }
 135
 136 int ip_tos_to_string_alloc(int i, char **s);
 137 int ip_tos_from_string(const char *s);
 138
 139 typedef enum {
 140         IFNAME_VALID_ALTERNATIVE = 1 << 0, /* Allow "altnames" too */
 141         IFNAME_VALID_NUMERIC     = 1 << 1, /* Allow decimal formatted ifindexes too */
 142         IFNAME_VALID_SPECIAL     = 1 << 2, /* Allow the special names "all" and "default" */
 143         _IFNAME_VALID_ALL        = IFNAME_VALID_ALTERNATIVE | IFNAME_VALID_NUMERIC | IFNAME_VALID_SPECIAL,
 144 } IfnameValidFlags;
 145 bool ifname_valid_char(char a);
 146 bool ifname_valid_full(const char *p, IfnameValidFlags flags);
 147 static inline bool ifname_valid(const char *p) {
 148         return ifname_valid_full(p, 0);
 149 }
 150 bool address_label_valid(const char *p);
 151
 152 int getpeercred(int fd, struct ucred *ucred);
 153 int getpeersec(int fd, char **ret);
 154 int getpeergroups(int fd, gid_t **ret);
 155
 156 ssize_t send_one_fd_iov_sa(
 157                 int transport_fd,
 158                 int fd,
 159                 const struct iovec *iov, size_t iovlen,
 160                 const struct sockaddr *sa, socklen_t len,
 161                 int flags);
 162 int send_one_fd_sa(int transport_fd,
 163                    int fd,
 164                    const struct sockaddr *sa, socklen_t len,
 165                    int flags);
 166 #define send_one_fd_iov(transport_fd, fd, iov, iovlen, flags) send_one_fd_iov_sa(transport_fd, fd, iov, iovlen, NULL, 0, flags)
 167 #define send_one_fd(transport_fd, fd, flags) send_one_fd_iov_sa(transport_fd, fd, NULL, 0, NULL, 0, flags)
 168 ssize_t receive_one_fd_iov(int transport_fd, struct iovec *iov, size_t iovlen, int flags, int *ret_fd);
 169 int receive_one_fd(int transport_fd, int flags);
 170
 171 ssize_t next_datagram_size_fd(int fd);
 172
 173 int flush_accept(int fd);
 174
 175 #define CMSG_FOREACH(cmsg, mh)                                          \
 176         for ((cmsg) = CMSG_FIRSTHDR(mh); (cmsg); (cmsg) = CMSG_NXTHDR((mh), (cmsg)))
 177
 178 struct cmsghdr* cmsg_find(struct msghdr *mh, int level, int type, socklen_t length);
 179
 180 /* Type-safe, dereferencing version of cmsg_find() */
 181 #define CMSG_FIND_DATA(mh, level, type, ctype) \
 182         ({                                                            \
 183                 struct cmsghdr *_found;                               \
 184                 _found = cmsg_find(mh, level, type, CMSG_LEN(sizeof(ctype))); \
 185                 (ctype*) (_found ? CMSG_DATA(_found) : NULL);         \
 186         })
 187
 188 /* Resolves to a type that can carry cmsghdr structures. Make sure things are properly aligned, i.e. the type
 189  * itself is placed properly in memory and the size is also aligned to what's appropriate for "cmsghdr"
 190  * structures. */
 191 #define CMSG_BUFFER_TYPE(size)                                          \
 192         union {                                                         \
 193                 struct cmsghdr cmsghdr;                                 \
 194                 uint8_t buf[size];                                      \
 195                 uint8_t align_check[(size) >= CMSG_SPACE(0) &&          \
 196                                     (size) == CMSG_ALIGN(size) ? 1 : -1]; \
 197         }
 198
 199 /*
 200  * Certain hardware address types (e.g Infiniband) do not fit into sll_addr
 201  * (8 bytes) and run over the structure. This macro returns the correct size that
 202  * must be passed to kernel.
 203  */
 204 #define SOCKADDR_LL_LEN(sa)                                             \
 205         ({                                                              \
 206                 const struct sockaddr_ll *_sa = &(sa);                  \
 207                 size_t _mac_len = sizeof(_sa->sll_addr);                \
 208                 assert(_sa->sll_family == AF_PACKET);                   \
 209                 if (be16toh(_sa->sll_hatype) == ARPHRD_ETHER)           \
 210                         _mac_len = MAX(_mac_len, (size_t) ETH_ALEN);    \
 211                 if (be16toh(_sa->sll_hatype) == ARPHRD_INFINIBAND)      \
 212                         _mac_len = MAX(_mac_len, (size_t) INFINIBAND_ALEN); \
 213                 offsetof(struct sockaddr_ll, sll_addr) + _mac_len;      \
 214         })
 215
 216 /* Covers only file system and abstract AF_UNIX socket addresses, but not unnamed socket addresses. */
 217 #define SOCKADDR_UN_LEN(sa)                                             \
 218         ({                                                              \
 219                 const struct sockaddr_un *_sa = &(sa);                  \
 220                 assert(_sa->sun_family == AF_UNIX);                     \
 221                 offsetof(struct sockaddr_un, sun_path) +                \
 222                         (_sa->sun_path[0] == 0 ?                        \
 223                          1 + strnlen(_sa->sun_path+1, sizeof(_sa->sun_path)-1) : \
 224                          strnlen(_sa->sun_path, sizeof(_sa->sun_path))+1); \
 225         })
 226
 227 #define SOCKADDR_LEN(saddr)                                             \
 228         ({                                                              \
 229                 const union sockaddr_union *__sa = &(saddr);            \
 230                 size_t _len;                                            \
 231                 switch (__sa->sa.sa_family) {                           \
 232                 case AF_INET:                                           \
 233                         _len = sizeof(struct sockaddr_in);              \
 234                         break;                                          \
 235                 case AF_INET6:                                          \
 236                         _len = sizeof(struct sockaddr_in6);             \
 237                         break;                                          \
 238                 case AF_UNIX:                                           \
 239                         _len = SOCKADDR_UN_LEN(__sa->un);               \
 240                         break;                                          \
 241                 case AF_PACKET:                                         \
 242                         _len = SOCKADDR_LL_LEN(__sa->ll);               \
 243                         break;                                          \
 244                 case AF_NETLINK:                                        \
 245                         _len = sizeof(struct sockaddr_nl);              \
 246                         break;                                          \
 247                 case AF_VSOCK:                                          \
 248                         _len = sizeof(struct sockaddr_vm);              \
 249                         break;                                          \
 250                 default:                                                \
 251                         assert_not_reached();                           \
 252                 }                                                       \
 253                 _len;                                                   \
 254         })
 255
 256 int socket_ioctl_fd(void);
 257
 258 int sockaddr_un_set_path(struct sockaddr_un *ret, const char *path);
 259
 260 static inline int setsockopt_int(int fd, int level, int optname, int value) {
 261         if (setsockopt(fd, level, optname, &value, sizeof(value)) < 0)
 262                 return -errno;
 263
 264         return 0;
 265 }
 266
 267 static inline int getsockopt_int(int fd, int level, int optname, int *ret) {
 268         int v;
 269         socklen_t sl = sizeof(v);
 270
 271         if (getsockopt(fd, level, optname, &v, &sl) < 0)
 272                 return negative_errno();
 273         if (sl != sizeof(v))
 274                 return -EIO;
 275
 276         *ret = v;
 277         return 0;
 278 }
 279
 280 int socket_bind_to_ifname(int fd, const char *ifname);
 281 int socket_bind_to_ifindex(int fd, int ifindex);
 282
 283 /* Define a 64bit version of timeval/timespec in any case, even on 32bit userspace. */
 284 struct timeval_large {
 285         uint64_t tvl_sec, tvl_usec;
 286 };
 287 struct timespec_large {
 288         uint64_t tvl_sec, tvl_nsec;
 289 };
 290
 291 /* glibc duplicates timespec/timeval on certain 32bit archs, once in 32bit and once in 64bit.
 292  * See __convert_scm_timestamps() in glibc source code. Hence, we need additional buffer space for them
 293  * to prevent from recvmsg_safe() returning -EXFULL. */
 294 #define CMSG_SPACE_TIMEVAL                                              \
 295         ((sizeof(struct timeval) == sizeof(struct timeval_large)) ?     \
 296          CMSG_SPACE(sizeof(struct timeval)) :                           \
 297          CMSG_SPACE(sizeof(struct timeval)) +                           \
 298          CMSG_SPACE(sizeof(struct timeval_large)))
 299 #define CMSG_SPACE_TIMESPEC                                             \
 300         ((sizeof(struct timespec) == sizeof(struct timespec_large)) ?   \
 301          CMSG_SPACE(sizeof(struct timespec)) :                          \
 302          CMSG_SPACE(sizeof(struct timespec)) +                          \
 303          CMSG_SPACE(sizeof(struct timespec_large)))
 304
 305 ssize_t recvmsg_safe(int sockfd, struct msghdr *msg, int flags);
 306
 307 int socket_get_family(int fd, int *ret);
 308 int socket_set_recvpktinfo(int fd, int af, bool b);
 309 int socket_set_unicast_if(int fd, int af, int ifi);
 310
 311 int socket_set_option(int fd, int af, int opt_ipv4, int opt_ipv6, int val);
 312 static inline int socket_set_recverr(int fd, int af, bool b) {
 313         return socket_set_option(fd, af, IP_RECVERR, IPV6_RECVERR, b);
 314 }
 315 static inline int socket_set_recvttl(int fd, int af, bool b) {
 316         return socket_set_option(fd, af, IP_RECVTTL, IPV6_RECVHOPLIMIT, b);
 317 }
 318 static inline int socket_set_ttl(int fd, int af, int ttl) {
 319         return socket_set_option(fd, af, IP_TTL, IPV6_UNICAST_HOPS, ttl);
 320 }
 321 static inline int socket_set_freebind(int fd, int af, bool b) {
 322         return socket_set_option(fd, af, IP_FREEBIND, IPV6_FREEBIND, b);
 323 }
 324 static inline int socket_set_transparent(int fd, int af, bool b) {
 325         return socket_set_option(fd, af, IP_TRANSPARENT, IPV6_TRANSPARENT, b);
 326 }
 327 static inline int socket_set_recvfragsize(int fd, int af, bool b) {
 328         return socket_set_option(fd, af, IP_RECVFRAGSIZE, IPV6_RECVFRAGSIZE, b);
 329 }
 330
 331 int socket_get_mtu(int fd, int af, size_t *ret);
 332
 333 /* an initializer for struct ucred that initialized all fields to the invalid value appropriate for each */
 334 #define UCRED_INVALID { .pid = 0, .uid = UID_INVALID, .gid = GID_INVALID }
 335
 336 int connect_unix_path(int fd, int dir_fd, const char *path);