Merge branch 'master' into forward-port

[sliver-openvswitch.git] / planetlab / pltap-ovs / pltap-ovs.c

diff --git a/planetlab/pltap-ovs/pltap-ovs.c b/planetlab/pltap-ovs/pltap-ovs.c
new file mode 100644 (file)
index 0000000..e1660b0
--- /dev/null
+++ b/planetlab/pltap-ovs/pltap-ovs.c
@@ -0,0 +1,141 @@
+#include <sys/un.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <errno.h>
+#include <linux/if.h>
+#include <linux/if_tun.h>
+
+#include "tunalloc.h"
+
+#define OVS_SOCK "/var/run/pl-ovs.control"
+
+void send_fd(int p, int fd, char* vif_name);
+
+char *appname;
+
+#define ERROR(msg)                                                             \
+        do {                                                                   \
+                fprintf(stderr, "%s: %s: %s", appname, msg, strerror(errno));  \
+                exit(1);                                                       \
+        } while (0)
+
+
+static
+int send_vif_fd(int sock_fd, int vif_fd, char *vif_name)
+{
+        int retval;
+        struct msghdr msg;
+        struct cmsghdr *p_cmsg;
+        struct iovec vec;
+        size_t cmsgbuf[CMSG_SPACE(sizeof(vif_fd)) / sizeof(size_t)];
+        int *p_fds;
+
+
+        msg.msg_control = cmsgbuf;
+        msg.msg_controllen = sizeof(cmsgbuf);
+        p_cmsg = CMSG_FIRSTHDR(&msg);
+        p_cmsg->cmsg_level = SOL_SOCKET;
+        p_cmsg->cmsg_type = SCM_RIGHTS;
+        p_cmsg->cmsg_len = CMSG_LEN(sizeof(vif_fd));
+        p_fds = (int *) CMSG_DATA(p_cmsg);
+        *p_fds = vif_fd;
+        msg.msg_controllen = p_cmsg->cmsg_len;
+        msg.msg_name = NULL;
+        msg.msg_namelen = 0;
+        msg.msg_iov = &vec;
+        msg.msg_iovlen = 1;
+        msg.msg_flags = 0;
+
+        /* Send the interface name as the iov */
+        vec.iov_base = vif_name;
+        vec.iov_len = strlen(vif_name)+1;
+
+        while ((retval = sendmsg(sock_fd, &msg, 0)) == -1 && errno == EINTR);
+        if (retval == -1) {
+                ERROR("sending file descriptor");
+        }
+        return 0;
+}
+
+void send_fd(int p, int fd, char* vif_name)
+{
+        int control_fd;
+        int accept_fd;
+        struct sockaddr_un addr, accept_addr;
+        socklen_t addr_len = sizeof(accept_addr);
+
+        control_fd = socket(AF_UNIX, SOCK_STREAM, 0);
+        if (control_fd == -1 && errno != ENOENT) {
+                ERROR("Could not create UNIX socket");
+        }
+
+        memset(&addr, 0, sizeof(struct sockaddr_un));
+        /* Clear structure */
+        addr.sun_family = AF_UNIX;
+        strncpy(addr.sun_path, OVS_SOCK,
+                        sizeof(addr.sun_path) - 1);
+
+        if (unlink(OVS_SOCK) == -1 && errno != ENOENT) {
+                ERROR("Could not unlink " OVS_SOCK " control socket");
+        }
+
+        if (bind(control_fd, (struct sockaddr *) &addr,
+                                sizeof(struct sockaddr_un)) == -1) {
+                ERROR("Could not bind to " OVS_SOCK " control socket");
+        }
+
+        if (listen(control_fd, 5) == -1) {
+                ERROR("listen on " OVS_SOCK " failed");
+        }
+        if (write(p, "1", 1) != 1) {
+                ERROR("writing on the synch pipe");
+        }
+        if ((accept_fd = accept(control_fd, (struct sockaddr*) &accept_addr,
+                                                &addr_len)) == -1) {
+                ERROR("accept on " OVS_SOCK " failed");
+        }
+        send_vif_fd(accept_fd, fd, vif_name);
+}
+
+int main(int argc, char* argv[])
+{
+        char if_name[IFNAMSIZ];
+        int p[2]; // synchronization pipe
+        char dummy;
+       int tun_fd;
+
+       (void) argc; // unused
+
+        if (pipe(p) < 0) {
+                ERROR("pipe");
+        }
+
+        tun_fd = tun_alloc(IFF_TAP, if_name);
+
+        appname = argv[0];
+
+        switch(fork()) {
+        case -1:
+                ERROR("fork");
+                exit(1);
+        case 0:
+                close(1);
+                open("/dev/null", O_WRONLY);
+                close(p[0]);
+                send_fd(p[1], tun_fd, if_name);
+                exit(0);
+        default:
+                close(p[1]);
+                if (read(p[0], &dummy, 1) != 1) {
+                        ERROR("reading from the synch pipe");
+                }
+                printf("%s\n", if_name);
+        }
+        return 0;
+}