Investigate software for interfacing with hardware via HTTP requests

[matches/MCTX3420.git] / testing / web2io / network.c

diff --git a/testing/web2io/network.c b/testing/web2io/network.c
new file mode 100644 (file)
index 0000000..1a1b862
--- /dev/null
+++ b/testing/web2io/network.c
@@ -0,0 +1,174 @@
+#include "network.h"
+#include <assert.h>
+#include <errno.h>
+#include <sys/select.h>
+#include "log.h"
+
+#define h_addr h_addr_list[0]
+
+
+
+
+
+int Network_get_port(int sfd)
+{
+       static struct sockaddr_in sin;
+       static socklen_t len = sizeof(struct sockaddr_in);
+
+       if (getsockname(sfd, (struct sockaddr *)&sin, &len) != 0)
+                error("Network_port", "getsockname : %s", strerror(errno));
+       return ntohs(sin.sin_port);
+}
+
+int Network_server_bind(int port, int * bound)
+{
+       int sfd = socket(PF_INET, SOCK_STREAM, 0);
+       if (sfd < 0)
+       {
+               error("Network_server", "Creating socket on port %d : %s", port, strerror(errno));
+       }
+
+       struct   sockaddr_in name;
+
+       name.sin_family = AF_INET;
+       name.sin_addr.s_addr = htonl(INADDR_ANY);
+       name.sin_port = htons(port);
+
+       if (bind( sfd, (struct sockaddr *) &name, sizeof(name) ) < 0)
+       {
+               error("Network_server", "Binding socket on port %d : %s", port, strerror(errno));
+       }
+
+       if (bound != NULL)
+               *bound = Network_get_port(sfd);
+       return sfd;     
+}
+
+int Network_server_listen(int sfd, char * addr)
+{
+       int port = Network_get_port(sfd);
+       if (listen(sfd, 1) < 0)
+       {
+               error("Network_server", "Listening on port %d : %s", port, strerror(errno));
+       }
+       
+       int psd;
+       if (addr == NULL)
+               psd = accept(sfd, 0, 0);
+       else
+       {
+               struct  sockaddr_in client;
+               struct  hostent *hp;
+
+               client.sin_family = AF_INET;
+               hp = gethostbyname(addr);
+               bcopy ( hp->h_addr, &(client.sin_addr.s_addr), hp->h_length);
+               client.sin_port = htons(port);
+               socklen_t len = sizeof(client);
+
+               psd = accept(sfd, (struct sockaddr*)&client, &len);
+       }
+       //close(sfd); // don't close the bind socket here; we might want to reuse the port
+       assert(psd >= 0);
+       return psd;
+}
+
+int Network_server(char * addr, int port)
+{
+       int bind = Network_server_bind(port, &port);
+       int sfd = Network_server_listen(bind, addr);
+       close(bind); // won't be able to reuse the port (it goes into TIME_WAIT)
+       return sfd;
+}
+
+int Network_client(const char * addr, int port, int timeout)
+{
+       int sfd = socket(PF_INET, SOCK_STREAM, 0);
+
+       //log_print(2, "Network_client", "Created socket");
+       long arg = fcntl(sfd, F_GETFL, NULL);
+       arg |= O_NONBLOCK;
+       fcntl(sfd, F_SETFL, arg);
+
+       if (sfd < 0)
+       {
+               error("Network_client", "Creating socket for address %s:%d : %s", addr, port, strerror(errno));
+       }
+       struct  sockaddr_in server;
+       struct  hostent *hp;
+
+
+       server.sin_family = AF_INET;
+       hp = gethostbyname(addr);
+       if (hp == NULL)
+       {
+               error("Network_client", "Can't get host by name %s", addr);
+       }
+       bcopy ( hp->h_addr, &(server.sin_addr.s_addr), hp->h_length);
+       server.sin_port = htons(port);
+
+
+       int res = connect(sfd, (struct sockaddr *) &server, sizeof(server));
+       
+
+       if (res < 0 && errno == EINPROGRESS)
+       {
+               
+               fd_set writeSet;
+               FD_ZERO(&writeSet);
+               FD_SET(sfd, &writeSet);
+
+               struct timeval tv;
+               tv.tv_sec = timeout;
+               tv.tv_usec = 0;
+
+               struct timeval * tp;
+               tp = (timeout < 0) ? NULL : &tv;
+               
+               int err = select(sfd+1, NULL, &writeSet, NULL, tp);
+               
+               if (err == 0)
+               {
+                       error("Network_client", "Timed out trying to connect to %s:%d after %d seconds", addr, port, timeout);
+               }
+               else if (err < 0)
+               {
+                       error("Network_client", "Connecting to %s:%d - Error in select(2) call : %s", addr, port, strerror(errno));
+               }
+               else if (FD_ISSET(sfd, &writeSet))
+               {
+                       int so_error;
+                       socklen_t len = sizeof so_error;
+                       getsockopt(sfd, SOL_SOCKET, SO_ERROR, &so_error, &len);
+                       if (so_error != 0)
+                       {
+                               error("Network_client", "Connecting to %s:%d : %s", addr, port, strerror(so_error));
+                       }
+               }
+               else
+               {
+                       error("Network_client", "select(2) returned %d but the socket is not writable!?", err);
+               }
+       }
+       else
+       {
+               error("Network_client", "Connecting to %s:%d : %s", addr, port, strerror(errno));
+       }
+
+       arg = fcntl(sfd, F_GETFL, NULL);
+       arg &= (~O_NONBLOCK);
+       fcntl(sfd, F_SETFL, arg);
+       
+       
+       
+       return sfd;
+}
+
+void Network_close(int sfd)
+{
+       if (shutdown(sfd, 2) != 0)
+       {
+               error("Network_close", "Closing socket : %s", strerror(errno));
+       }
+       close(sfd);
+}