socket.h

   1 /*
   2   chronyd/chronyc - Programs for keeping computer clocks accurate.
   3
   4  **********************************************************************
   5  * Copyright (C) Miroslav Lichvar  2019
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of version 2 of the GNU General Public License as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  19  *
  20  **********************************************************************
  21
  22   =======================================================================
  23
  24   This is the header file for socket operations.
  25
  26   */
  27
  28 #ifndef GOT_SOCKET_H
  29 #define GOT_SOCKET_H
  30
  31 #include "addressing.h"
  32
  33 /* Flags for opening sockets */
  34 #define SCK_FLAG_BLOCK 1
  35 #define SCK_FLAG_BROADCAST 2
  36 #define SCK_FLAG_RX_DEST_ADDR 4
  37 #define SCK_FLAG_ALL_PERMISSIONS 8
  38 #define SCK_FLAG_PRIV_BIND 16
  39
  40 /* Flags for receiving and sending messages */
  41 #define SCK_FLAG_MSG_ERRQUEUE 1
  42 #define SCK_FLAG_MSG_DESCRIPTOR 2
  43
  44 typedef enum {
  45   SCK_ADDR_UNSPEC = 0,
  46   SCK_ADDR_IP,
  47   SCK_ADDR_UNIX
  48 } SCK_AddressType;
  49
  50 typedef struct {
  51   void *data;
  52   int length;
  53   SCK_AddressType addr_type;
  54   int if_index;
  55
  56   union {
  57     IPSockAddr ip;
  58     const char *path;
  59   } remote_addr;
  60
  61   union {
  62     IPAddr ip;
  63   } local_addr;
  64
  65   struct {
  66     struct timespec kernel;
  67     struct timespec hw;
  68     int if_index;
  69     int l2_length;
  70     int tx_flags;
  71   } timestamp;
  72
  73   int descriptor;
  74 } SCK_Message;
  75
  76 /* Initialisation function (the specified IP family is enabled,
  77    or all if IPADDR_UNSPEC) */
  78 extern void SCK_Initialise(int family);
  79
  80 /* Finalisation function */
  81 extern void SCK_Finalise(void);
  82
  83 /* Check if support for the IP family is enabled */
  84 extern int SCK_IsIpFamilyEnabled(int family);
  85
  86 /* Get the 0.0.0.0/::0 or 127.0.0.1/::1 address */
  87 extern void SCK_GetAnyLocalIPAddress(int family, IPAddr *local_addr);
  88 extern void SCK_GetLoopbackIPAddress(int family, IPAddr *local_addr);
  89
  90 /* Check if an IP address is a link-local address */
  91 extern int SCK_IsLinkLocalIPAddress(IPAddr *addr);
  92
  93 /* Specify a bind()-like function for binding sockets to privileged ports when
  94    running in a restricted process (e.g. after dropping root privileges) */
  95 extern void SCK_SetPrivBind(int (*function)(int sock_fd, struct sockaddr *address,
  96                                             socklen_t address_len));
  97
  98 /* Open a socket (addresses and iface may be NULL) */
  99 extern int SCK_OpenUdpSocket(IPSockAddr *remote_addr, IPSockAddr *local_addr,
 100                              const char *iface, int flags);
 101 extern int SCK_OpenTcpSocket(IPSockAddr *remote_addr, IPSockAddr *local_addr,
 102                              const char *iface, int flags);
 103 extern int SCK_OpenUnixDatagramSocket(const char *remote_addr, const char *local_addr,
 104                                       int flags);
 105 extern int SCK_OpenUnixStreamSocket(const char *remote_addr, const char *local_addr,
 106                                     int flags);
 107 extern int SCK_OpenUnixSocketPair(int flags, int *other_fd);
 108
 109 /* Set and get a socket option of int size */
 110 extern int SCK_SetIntOption(int sock_fd, int level, int name, int value);
 111 extern int SCK_GetIntOption(int sock_fd, int level, int name, int *value);
 112
 113 /* Enable RX timestamping socket option */
 114 extern int SCK_EnableKernelRxTimestamping(int sock_fd);
 115
 116 /* Operate on a stream socket - listen()/accept()/shutdown() wrappers */
 117 extern int SCK_ListenOnSocket(int sock_fd, int backlog);
 118 extern int SCK_AcceptConnection(int sock_fd, IPSockAddr *remote_addr);
 119 extern int SCK_ShutdownConnection(int sock_fd);
 120
 121 /* Receive and send data on connected sockets - recv()/send() wrappers */
 122 extern int SCK_Receive(int sock_fd, void *buffer, int length, int flags);
 123 extern int SCK_Send(int sock_fd, const void *buffer, int length, int flags);
 124
 125 /* Receive a single message or multiple messages.  The functions return
 126    a pointer to static buffers, or NULL on error.  The buffers are valid until
 127    another call of the functions and can be reused for sending messages. */
 128 extern SCK_Message *SCK_ReceiveMessage(int sock_fd, int flags);
 129 extern SCK_Message *SCK_ReceiveMessages(int sock_fd, int flags, int *num_messages);
 130
 131 /* Initialise a new message (e.g. before sending) */
 132 extern void SCK_InitMessage(SCK_Message *message, SCK_AddressType addr_type);
 133
 134 /* Send a message */
 135 extern int SCK_SendMessage(int sock_fd, SCK_Message *message, int flags);
 136
 137 /* Remove bound Unix socket */
 138 extern int SCK_RemoveSocket(int sock_fd);
 139
 140 /* Close the socket */
 141 extern void SCK_CloseSocket(int sock_fd);
 142
 143 /* Convert between IPSockAddr and sockaddr_in/in6 */
 144 extern void SCK_SockaddrToIPSockAddr(struct sockaddr *sa, int sa_length, IPSockAddr *ip_sa);
 145 extern int SCK_IPSockAddrToSockaddr(IPSockAddr *ip_sa, struct sockaddr *sa, int sa_length);
 146
 147 #endif