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author | Laurent Bercot <ska-skaware@skarnet.org> | 2014-09-18 18:55:44 +0000 |
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committer | Laurent Bercot <ska-skaware@skarnet.org> | 2014-09-18 18:55:44 +0000 |
commit | 3534b428629be185e096be99e3bd5fdfe32d5544 (patch) | |
tree | 210ef3198ed66bc7f7b7bf6a85e4579f455e5a36 /src/sysdeps/tryancilautoclose.c | |
download | skalibs-3534b428629be185e096be99e3bd5fdfe32d5544.tar.xz |
initial commit with rc for skalibs-2.0.0.0
Diffstat (limited to 'src/sysdeps/tryancilautoclose.c')
-rw-r--r-- | src/sysdeps/tryancilautoclose.c | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/src/sysdeps/tryancilautoclose.c b/src/sysdeps/tryancilautoclose.c new file mode 100644 index 0000000..7b4a563 --- /dev/null +++ b/src/sysdeps/tryancilautoclose.c @@ -0,0 +1,116 @@ +/* ISC license. */ + +#undef _POSIX_C_SOURCE +#undef _XOPEN_SOURCE + +#ifndef _XPG4_2 +# define _XPG4_2 +#endif + +#include <sys/types.h> +#include <unistd.h> +#include <errno.h> +#include <sys/socket.h> +#include <sys/uio.h> +#if defined(__FreeBSD__) +# include <sys/param.h> +#endif + +typedef struct ancilbuf_s ancilbuf_t, *ancilbuf_t_ref ; +struct ancilbuf_s +{ + struct cmsghdr h ; + int fd ; +} ; + +static int ancil_send_fd (int sock, int fd) +{ + struct msghdr msghdr ; + struct iovec nothing_ptr ; + ancilbuf_t buf ; + struct cmsghdr *cmsg ; + char nothing = '!' ; + + nothing_ptr.iov_base = ¬hing ; + nothing_ptr.iov_len = 1 ; + msghdr.msg_name = 0 ; + msghdr.msg_namelen = 0 ; + msghdr.msg_iov = ¬hing_ptr ; + msghdr.msg_iovlen = 1 ; + msghdr.msg_flags = 0 ; + msghdr.msg_control = &buf ; + msghdr.msg_controllen = sizeof(ancilbuf_t) ; + cmsg = CMSG_FIRSTHDR(&msghdr) ; + cmsg->cmsg_len = msghdr.msg_controllen ; + cmsg->cmsg_level = SOL_SOCKET ; + cmsg->cmsg_type = SCM_RIGHTS ; + *((int *)CMSG_DATA(cmsg)) = fd ; + return (sendmsg(sock, &msghdr, 0) >= 0) ; +} + +static int ancil_recv_fd (int sock) +{ + struct msghdr msghdr ; + struct iovec nothing_ptr ; + ancilbuf_t buf ; + struct cmsghdr *cmsg ; + char nothing ; + + nothing_ptr.iov_base = ¬hing ; + nothing_ptr.iov_len = 1 ; + msghdr.msg_name = 0 ; + msghdr.msg_namelen = 0 ; + msghdr.msg_iov = ¬hing_ptr ; + msghdr.msg_iovlen = 1 ; + msghdr.msg_flags = 0 ; + msghdr.msg_control = &buf ; + msghdr.msg_controllen = sizeof(ancilbuf_t) ; + cmsg = CMSG_FIRSTHDR(&msghdr) ; + cmsg->cmsg_len = msghdr.msg_controllen ; + cmsg->cmsg_level = SOL_SOCKET ; + cmsg->cmsg_type = SCM_RIGHTS ; + *((int *)CMSG_DATA(cmsg)) = -1 ; + if (recvmsg(sock, &msghdr, 0) < 0) return -1 ; + return *((int *)CMSG_DATA(cmsg)) ; +} + +static int client (int sock) +{ + int p ; + char c ; + if (read(sock, &c, 1) < 1) return 111 ; + if (c != 'b') return 111 ; + p = ancil_recv_fd(sock) ; + if (p < 0) return 111 ; + if (read(sock, &c, 1) < 1) return 111 ; + if (c != 'a') return 111 ; + if (read(p, &c, 1) < 1) return 111 ; + if (c != 'K') return 111 ; + if (read(p, &c, 1) < 1) return 111 ; + return c ; +} + +static void server (int sock) +{ + int p[2] ; + char c = 1 ; + if (pipe(p) < 0) return ; + if (write(sock, "b", 1) < 1) return ; + if (!ancil_send_fd(sock, p[0])) return ; + if (write(sock, "a", 1) < 1) return ; + if (write(p[1], "K", 1) < 1) return ; + if ((close(p[0]) < 0) && (errno == EBADF)) c = 0 ; + write(p[1], &c, 1) ; +} + +int main (void) +{ + int fd[2] ; + if (socketpair(AF_UNIX, SOCK_STREAM, 0, fd) < 0) return 111 ; + switch (fork()) + { + case -1 : return 111 ; + case 0 : close(fd[0]) ; server(fd[1]) ; return 0 ; + default : close(fd[1]) ; return client(fd[0]) ; + } +} |