usock.c

   1 #include <sys/types.h>
   2 #include <sys/socket.h>
   3 #include <sys/un.h>
   4 #include <netdb.h>
   5 #include <stdlib.h>
   6 #include <unistd.h>
   7 #include <fcntl.h>
   8 #include <errno.h>
   9 #include <string.h>
  10 #include <stdbool.h>
  11
  12 #include "usock.h"
  13
  14 static void usock_set_flags(int sock, unsigned int type)
  15 {
  16         if (!(type & USOCK_NOCLOEXEC))
  17                 fcntl(sock, F_SETFD, fcntl(sock, F_GETFD) | FD_CLOEXEC);
  18
  19         if (type & USOCK_NONBLOCK)
  20                 fcntl(sock, F_SETFL, fcntl(sock, F_GETFL) | O_NONBLOCK);
  21 }
  22
  23 static int usock_connect(struct sockaddr *sa, int sa_len, int family, int socktype, bool server)
  24 {
  25         int sock;
  26
  27         sock = socket(family, socktype, 0);
  28         if (sock < 0)
  29                 return -1;
  30
  31         if (server) {
  32                 const int one = 1;
  33                 setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
  34
  35                 if (!bind(sock, sa, sa_len) &&
  36                     (socktype != SOCK_STREAM || !listen(sock, SOMAXCONN)))
  37                         return sock;
  38         } else {
  39                 if (!connect(sock, sa, sa_len) || errno == EINPROGRESS)
  40                         return sock;
  41         }
  42
  43         close(sock);
  44         return -1;
  45 }
  46
  47 static int usock_unix(const char *host, int socktype, bool server)
  48 {
  49         struct sockaddr_un sun = {.sun_family = AF_UNIX};
  50
  51         if (strlen(host) >= sizeof(sun.sun_path)) {
  52                 errno = EINVAL;
  53                 return -1;
  54         }
  55         strcpy(sun.sun_path, host);
  56
  57         return usock_connect((struct sockaddr*)&sun, sizeof(sun), AF_UNIX, socktype, server);
  58 }
  59
  60 static int usock_inet(int type, const char *host, const char *service, int socktype, bool server)
  61 {
  62         struct addrinfo *result, *rp;
  63         struct addrinfo hints = {
  64                 .ai_family = (type & USOCK_IPV6ONLY) ? AF_INET6 :
  65                         (type & USOCK_IPV4ONLY) ? AF_INET : AF_UNSPEC,
  66                 .ai_socktype = socktype,
  67                 .ai_flags = AI_ADDRCONFIG
  68                         | ((type & USOCK_SERVER) ? AI_PASSIVE : 0)
  69                         | ((type & USOCK_NUMERIC) ? AI_NUMERICHOST : 0),
  70         };
  71         int sock = -1;
  72
  73         if (getaddrinfo(host, service, &hints, &result))
  74                 return -1;
  75
  76         for (rp = result; rp != NULL; rp = rp->ai_next) {
  77                 sock = usock_connect(rp->ai_addr, rp->ai_addrlen, rp->ai_family, socktype, server);
  78                 if (sock >= 0)
  79                         break;
  80         }
  81
  82         freeaddrinfo(result);
  83         return sock;
  84 }
  85
  86 int usock(int type, const char *host, const char *service) {
  87         int socktype = ((type & 0xff) == USOCK_TCP) ? SOCK_STREAM : SOCK_DGRAM;
  88         bool server = !!(type & USOCK_SERVER);
  89         int sock;
  90
  91         if (type & USOCK_UNIX)
  92                 sock = usock_unix(host, socktype, server);
  93         else
  94                 sock = usock_inet(type, host, service, socktype, server);
  95
  96         if (sock < 0)
  97                 return -1;
  98
  99         usock_set_flags(sock, type);
 100         return sock;
 101 }