src/basic/socket-util.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   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 "macro.h"
  18 #include "missing_socket.h"
  19 #include "sparse-endian.h"
  20
  21 union sockaddr_union {
  22         /* The minimal, abstract version */
  23         struct sockaddr sa;
  24
  25         /* The libc provided version that allocates "enough room" for every protocol */
  26         struct sockaddr_storage storage;
  27
  28         /* Protoctol-specific implementations */
  29         struct sockaddr_in in;
  30         struct sockaddr_in6 in6;
  31         struct sockaddr_un un;
  32         struct sockaddr_nl nl;
  33         struct sockaddr_ll ll;
  34         struct sockaddr_vm vm;
  35
  36         /* Ensure there is enough space to store Infiniband addresses */
  37         uint8_t ll_buffer[offsetof(struct sockaddr_ll, sll_addr) + CONST_MAX(ETH_ALEN, INFINIBAND_ALEN)];
  38
  39         /* Ensure there is enough space after the AF_UNIX sun_path for one more NUL byte, just to be sure that the path
  40          * component is always followed by at least one NUL byte. */
  41         uint8_t un_buffer[sizeof(struct sockaddr_un) + 1];
  42 };
  43
  44 #define SUN_PATH_LEN (sizeof(((struct sockaddr_un){}).sun_path))
  45
  46 typedef struct SocketAddress {
  47         union sockaddr_union sockaddr;
  48
  49         /* We store the size here explicitly due to the weird
  50          * sockaddr_un semantics for abstract sockets */
  51         socklen_t size;
  52
  53         /* Socket type, i.e. SOCK_STREAM, SOCK_DGRAM, ... */
  54         int type;
  55
  56         /* Socket protocol, IPPROTO_xxx, usually 0, except for netlink */
  57         int protocol;
  58 } SocketAddress;
  59
  60 typedef enum SocketAddressBindIPv6Only {
  61         SOCKET_ADDRESS_DEFAULT,
  62         SOCKET_ADDRESS_BOTH,
  63         SOCKET_ADDRESS_IPV6_ONLY,
  64         _SOCKET_ADDRESS_BIND_IPV6_ONLY_MAX,
  65         _SOCKET_ADDRESS_BIND_IPV6_ONLY_INVALID = -1
  66 } SocketAddressBindIPv6Only;
  67
  68 #define socket_address_family(a) ((a)->sockaddr.sa.sa_family)
  69
  70 const char* socket_address_type_to_string(int t) _const_;
  71 int socket_address_type_from_string(const char *s) _pure_;
  72
  73 int sockaddr_un_unlink(const struct sockaddr_un *sa);
  74
  75 static inline int socket_address_unlink(const SocketAddress *a) {
  76         return socket_address_family(a) == AF_UNIX ? sockaddr_un_unlink(&a->sockaddr.un) : 0;
  77 }
  78
  79 bool socket_address_can_accept(const SocketAddress *a) _pure_;
  80
  81 int socket_address_listen(
  82                 const SocketAddress *a,
  83                 int flags,
  84                 int backlog,
  85                 SocketAddressBindIPv6Only only,
  86                 const char *bind_to_device,
  87                 bool reuse_port,
  88                 bool free_bind,
  89                 bool transparent,
  90                 mode_t directory_mode,
  91                 mode_t socket_mode,
  92                 const char *label);
  93
  94 int socket_address_verify(const SocketAddress *a, bool strict) _pure_;
  95 int socket_address_print(const SocketAddress *a, char **p);
  96 bool socket_address_matches_fd(const SocketAddress *a, int fd);
  97
  98 bool socket_address_equal(const SocketAddress *a, const SocketAddress *b) _pure_;
  99
 100 const char* socket_address_get_path(const SocketAddress *a);
 101
 102 bool socket_ipv6_is_supported(void);
 103
 104 int sockaddr_port(const struct sockaddr *_sa, unsigned *port);
 105
 106 int sockaddr_pretty(const struct sockaddr *_sa, socklen_t salen, bool translate_ipv6, bool include_port, char **ret);
 107 int getpeername_pretty(int fd, bool include_port, char **ret);
 108 int getsockname_pretty(int fd, char **ret);
 109
 110 int socknameinfo_pretty(union sockaddr_union *sa, socklen_t salen, char **_ret);
 111
 112 const char* socket_address_bind_ipv6_only_to_string(SocketAddressBindIPv6Only b) _const_;
 113 SocketAddressBindIPv6Only socket_address_bind_ipv6_only_from_string(const char *s) _pure_;
 114 SocketAddressBindIPv6Only socket_address_bind_ipv6_only_or_bool_from_string(const char *s);
 115
 116 int netlink_family_to_string_alloc(int b, char **s);
 117 int netlink_family_from_string(const char *s) _pure_;
 118
 119 bool sockaddr_equal(const union sockaddr_union *a, const union sockaddr_union *b);
 120
 121 int fd_set_sndbuf(int fd, size_t n, bool increase);
 122 static inline int fd_inc_sndbuf(int fd, size_t n) {
 123         return fd_set_sndbuf(fd, n, true);
 124 }
 125 int fd_set_rcvbuf(int fd, size_t n, bool increase);
 126 static inline int fd_inc_rcvbuf(int fd, size_t n) {
 127         return fd_set_rcvbuf(fd, n, true);
 128 }
 129
 130 int ip_tos_to_string_alloc(int i, char **s);
 131 int ip_tos_from_string(const char *s);
 132
 133 typedef enum {
 134       IFNAME_VALID_ALTERNATIVE = 1 << 0,
 135       IFNAME_VALID_NUMERIC     = 1 << 1,
 136       _IFNAME_VALID_ALL        = IFNAME_VALID_ALTERNATIVE | IFNAME_VALID_NUMERIC,
 137 } IfnameValidFlags;
 138 bool ifname_valid_full(const char *p, IfnameValidFlags flags);
 139 static inline bool ifname_valid(const char *p) {
 140         return ifname_valid_full(p, 0);
 141 }
 142 bool address_label_valid(const char *p);
 143
 144 int getpeercred(int fd, struct ucred *ucred);
 145 int getpeersec(int fd, char **ret);
 146 int getpeergroups(int fd, gid_t **ret);
 147
 148 ssize_t send_one_fd_iov_sa(
 149                 int transport_fd,
 150                 int fd,
 151                 struct iovec *iov, size_t iovlen,
 152                 const struct sockaddr *sa, socklen_t len,
 153                 int flags);
 154 int send_one_fd_sa(int transport_fd,
 155                    int fd,
 156                    const struct sockaddr *sa, socklen_t len,
 157                    int flags);
 158 #define send_one_fd_iov(transport_fd, fd, iov, iovlen, flags) send_one_fd_iov_sa(transport_fd, fd, iov, iovlen, NULL, 0, flags)
 159 #define send_one_fd(transport_fd, fd, flags) send_one_fd_iov_sa(transport_fd, fd, NULL, 0, NULL, 0, flags)
 160 ssize_t receive_one_fd_iov(int transport_fd, struct iovec *iov, size_t iovlen, int flags, int *ret_fd);
 161 int receive_one_fd(int transport_fd, int flags);
 162
 163 ssize_t next_datagram_size_fd(int fd);
 164
 165 int flush_accept(int fd);
 166
 167 #define CMSG_FOREACH(cmsg, mh)                                          \
 168         for ((cmsg) = CMSG_FIRSTHDR(mh); (cmsg); (cmsg) = CMSG_NXTHDR((mh), (cmsg)))
 169
 170 struct cmsghdr* cmsg_find(struct msghdr *mh, int level, int type, socklen_t length);
 171
 172 /* Type-safe, dereferencing version of cmsg_find() */
 173 #define CMSG_FIND_DATA(mh, level, type, ctype) \
 174         ({                                                            \
 175                 struct cmsghdr *_found;                               \
 176                 _found = cmsg_find(mh, level, type, CMSG_LEN(sizeof(ctype))); \
 177                 (ctype*) (_found ? CMSG_DATA(_found) : NULL);         \
 178         })
 179
 180 /* Resolves to a type that can carry cmsghdr structures. Make sure things are properly aligned, i.e. the type
 181  * itself is placed properly in memory and the size is also aligned to what's appropriate for "cmsghdr"
 182  * structures. */
 183 #define CMSG_BUFFER_TYPE(size)                                          \
 184         union {                                                         \
 185                 struct cmsghdr cmsghdr;                                 \
 186                 uint8_t buf[size];                                      \
 187                 uint8_t align_check[(size) >= CMSG_SPACE(0) &&          \
 188                                     (size) == CMSG_ALIGN(size) ? 1 : -1]; \
 189         }
 190
 191 /*
 192  * Certain hardware address types (e.g Infiniband) do not fit into sll_addr
 193  * (8 bytes) and run over the structure. This macro returns the correct size that
 194  * must be passed to kernel.
 195  */
 196 #define SOCKADDR_LL_LEN(sa)                                             \
 197         ({                                                              \
 198                 const struct sockaddr_ll *_sa = &(sa);                  \
 199                 size_t _mac_len = sizeof(_sa->sll_addr);                \
 200                 assert(_sa->sll_family == AF_PACKET);                   \
 201                 if (be16toh(_sa->sll_hatype) == ARPHRD_ETHER)           \
 202                         _mac_len = MAX(_mac_len, (size_t) ETH_ALEN);    \
 203                 if (be16toh(_sa->sll_hatype) == ARPHRD_INFINIBAND)      \
 204                         _mac_len = MAX(_mac_len, (size_t) INFINIBAND_ALEN); \
 205                 offsetof(struct sockaddr_ll, sll_addr) + _mac_len;      \
 206         })
 207
 208 /* Covers only file system and abstract AF_UNIX socket addresses, but not unnamed socket addresses. */
 209 #define SOCKADDR_UN_LEN(sa)                                             \
 210         ({                                                              \
 211                 const struct sockaddr_un *_sa = &(sa);                  \
 212                 assert(_sa->sun_family == AF_UNIX);                     \
 213                 offsetof(struct sockaddr_un, sun_path) +                \
 214                         (_sa->sun_path[0] == 0 ?                        \
 215                          1 + strnlen(_sa->sun_path+1, sizeof(_sa->sun_path)-1) : \
 216                          strnlen(_sa->sun_path, sizeof(_sa->sun_path))+1); \
 217         })
 218
 219 #define SOCKADDR_LEN(sa)                                                \
 220         ({                                                              \
 221                 const union sockaddr_union *__sa = &(sa);               \
 222                 size_t _len;                                            \
 223                 switch(__sa->sa.sa_family) {                            \
 224                 case AF_INET:                                           \
 225                         _len = sizeof(struct sockaddr_in);              \
 226                         break;                                          \
 227                 case AF_INET6:                                          \
 228                         _len = sizeof(struct sockaddr_in6);             \
 229                         break;                                          \
 230                 case AF_UNIX:                                           \
 231                         _len = SOCKADDR_UN_LEN(__sa->un);               \
 232                         break;                                          \
 233                 case AF_PACKET:                                         \
 234                         _len = SOCKADDR_LL_LEN(__sa->ll);               \
 235                         break;                                          \
 236                 case AF_NETLINK:                                        \
 237                         _len = sizeof(struct sockaddr_nl);              \
 238                         break;                                          \
 239                 case AF_VSOCK:                                          \
 240                         _len = sizeof(struct sockaddr_vm);              \
 241                         break;                                          \
 242                 default:                                                \
 243                         assert_not_reached("invalid socket family");    \
 244                 }                                                       \
 245                 _len;                                                   \
 246         })
 247
 248 int socket_ioctl_fd(void);
 249
 250 int sockaddr_un_set_path(struct sockaddr_un *ret, const char *path);
 251
 252 static inline int setsockopt_int(int fd, int level, int optname, int value) {
 253         if (setsockopt(fd, level, optname, &value, sizeof(value)) < 0)
 254                 return -errno;
 255
 256         return 0;
 257 }
 258
 259 int socket_bind_to_ifname(int fd, const char *ifname);
 260 int socket_bind_to_ifindex(int fd, int ifindex);
 261
 262 ssize_t recvmsg_safe(int sockfd, struct msghdr *msg, int flags);
 263
 264 int socket_get_family(int fd, int *ret);
 265 int socket_set_recvpktinfo(int fd, int af, bool b);
 266 int socket_set_recverr(int fd, int af, bool b);
 267 int socket_set_recvttl(int fd, int af, bool b);
 268 int socket_set_ttl(int fd, int af, int ttl);
 269 int socket_set_unicast_if(int fd, int af, int ifi);
 270 int socket_set_freebind(int fd, int af, bool b);
 271 int socket_set_transparent(int fd, int af, bool b);