Messages in this thread | | | Subject | Re: [PATCH] um: add a generic "fd" vector transport | From | Anton Ivanov <> | Date | Thu, 9 Apr 2020 14:20:36 +0100 |
| |
On 07/04/2020 21:28, Marc-André Lureau wrote: > Learn to take a pre-opened file-descriptor for vector IO. > > Instead of teaching the driver to open a FD in multiple ways, it can > rely on management layer to do it on its behalf. For example, this > allows inheriting a preconfigured device fd or a simple socketpair() > setup, without further arguments, privileges or system access by UML. > > Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> > --- > arch/um/drivers/vector_user.c | 59 +++++++++++++++++++++++++++++++++++ > 1 file changed, 59 insertions(+) > > diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c > index 29fae0456ade..45c1550dbb37 100644 > --- a/arch/um/drivers/vector_user.c > +++ b/arch/um/drivers/vector_user.c > @@ -29,6 +29,7 @@ > #include <netdb.h> > #include <stdlib.h> > #include <os.h> > +#include <limits.h> > #include <um_malloc.h> > #include "vector_user.h" > > @@ -42,6 +43,9 @@ > #define TRANS_RAW "raw" > #define TRANS_RAW_LEN strlen(TRANS_RAW) > > +#define TRANS_FD "fd" > +#define TRANS_FD_LEN strlen(TRANS_FD) > + > #define VNET_HDR_FAIL "could not enable vnet headers on fd %d" > #define TUN_GET_F_FAIL "tapraw: TUNGETFEATURES failed: %s" > #define L2TPV3_BIND_FAIL "l2tpv3_open : could not bind socket err=%i" > @@ -347,6 +351,59 @@ static struct vector_fds *user_init_unix_fds(struct arglist *ifspec, int id) > return NULL; > } > > +static int strtofd(const char *nptr) > +{ > + long fd; > + char *endptr; > + > + if (nptr == NULL) > + return -1; > + > + errno = 0; > + fd = strtol(nptr, &endptr, 10); > + if (nptr == endptr || > + errno != 0 || > + *endptr != '\0' || > + fd < 0 || > + fd > INT_MAX) { > + return -1; > + } > + return fd; > +} > + > +static struct vector_fds *user_init_fd_fds(struct arglist *ifspec) > +{ > + int fd = -1; > + char *fdarg = NULL; > + struct vector_fds *result = NULL; > + > + fdarg = uml_vector_fetch_arg(ifspec, "fd"); > + fd = strtofd(fdarg); > + if (fd == -1) { > + printk(UM_KERN_ERR "fd open: bad or missing fd argument"); > + goto fd_cleanup; > + } > + > + result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL); > + if (result == NULL) { > + printk(UM_KERN_ERR "fd open: allocation failed"); > + goto fd_cleanup; > + } > + > + result->rx_fd = fd; > + result->tx_fd = fd; > + result->remote_addr_size = 0; > + result->remote_addr = NULL; > + return result; > + > +fd_cleanup: > + if (fd >= 0) > + os_close_file(fd); > + if (result != NULL) > + kfree(result); > + return NULL; > +} > + > static struct vector_fds *user_init_raw_fds(struct arglist *ifspec) > { > int rxfd = -1, txfd = -1; > @@ -578,6 +635,8 @@ struct vector_fds *uml_vector_user_open( > return user_init_socket_fds(parsed, ID_L2TPV3); > if (strncmp(transport, TRANS_BESS, TRANS_BESS_LEN) == 0) > return user_init_unix_fds(parsed, ID_BESS); > + if (strncmp(transport, TRANS_FD, TRANS_FD_LEN) == 0) > + return user_init_fd_fds(parsed); > return NULL; > } > Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
-- Anton R. Ivanov Cambridgegreys Limited. Registered in England. Company Number 10273661 https://www.cambridgegreys.com/
| |