Hello, Samir. Did you receive the following messages? Since these messages were dropped at vger.kernel.org , I'm worrying that you couldn't receive the following messages. Tetsuo Handa wrote: > Hello. > > Samir Bellabes wrote: > > >> what differences between you approach and netfilter in this case ? if > > >> it's about packet filtering, you already have all you wishes in > > >> netfilter project. > > > Except a hook for making decision with the name of process who picks that packet up known. > > > > I think that we really don't need it, because we can catch the > > informations as I explained. > > Well, I haven't understood yet why we don't need it. > > How can you know the the name of process who copies that datagram to its userspace memory? > A socket may be shared by multiple different executable files, > so the name of the executable file is not known until > one of processes who share the socket issues accept()/recvmsg() syscall. > > Are you saying that I should not use the name of the executable file? > > Regards. > Tetsuo Handa wrote: > Hello. > > I made an example. > > Usage: > > Compile app1 and app2 and run /tmp/app1 . > > Run something like > curl http://localhost:10000/ > to connect to /tmp/app1. > > I want to know that */tmp/app2* accepts TCP connection > so that the user can control > whether this TCP connection from 127.0.0.1 port N > should be accepted by */tmp/app2* or not. > > How can we do this without socket_post_accept() change? > > Regards. > > ---------- app1.c start ---------- > /* gcc -Wall -O2 -o /tmp/app1 app1.c */ > #include <fcntl.h> > #include <netinet/in.h> > #include <stdio.h> > #include <string.h> > #include <sys/select.h> > #include <sys/socket.h> > #include <sys/types.h> > #include <unistd.h> > > int main(int argc, char *argv[]) { > const int fd = socket(PF_INET, SOCK_STREAM, 0); > struct sockaddr_in addr; > char buf[16]; > memset(&addr, 0, sizeof(addr)); > addr.sin_family = AF_INET; > addr.sin_addr.s_addr = htonl(INADDR_ANY); > addr.sin_port = htons(10000); > fprintf(stderr, "%s started.\n", argv[0]); > if (bind(fd, (struct sockaddr *) &addr, sizeof(addr))) { > fprintf(stderr, "Can't bind()\n"); > return 1; > } else if (listen(fd, 5)) { > fprintf(stderr, "Can't listen()\n"); > return 1; > } > while (1) { > fd_set rfds; > FD_ZERO(&rfds); > FD_SET(fd, &rfds); > select(fd + 1, &rfds, NULL, NULL, NULL); > if (FD_ISSET(fd, &rfds)) break; > fprintf(stderr, "Can't select()\n"); > return 1; > } > if (fcntl(fd, FD_CLOEXEC, 0)) { > fprintf(stderr, "Can't fcntl()\n"); > return 1; > } > snprintf(buf, sizeof(buf), "%d", fd); > execlp("/tmp/app2", "app2", buf, NULL); > fprintf(stderr, "Can't execve()\n"); > return 1; > } > ---------- app1.c end ---------- > > ---------- app2.c start ---------- > /* gcc -Wall -O2 -o /tmp/app2 app2.c */ > #include <netinet/in.h> > #include <stdio.h> > #include <stdlib.h> > #include <sys/socket.h> > #include <sys/types.h> > #include <unistd.h> > > int main(int argc, char *argv[]) { > int lfd; > if (argc != 2) { > fprintf(stderr, "Bad parameter.\n"); > return 1; > } > fprintf(stderr, "%s started.\n", argv[0]); > lfd = atoi(argv[1]); > while (1) { > struct sockaddr_in addr; > socklen_t size = sizeof(addr); > int fd = accept(lfd, (struct sockaddr *) &addr, &size); > char c; > if (fd == EOF) { > fprintf(stderr, "Can't accept()\n"); > return 1; > } > while (read(fd, &c, 1) == 1 && write(fd, &c, 1) == 1); > close(fd); > } > return 0; > } > ---------- app2.c end ---------- > - To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
