vhost: validate FDs attached to messages

Some message handlers do not expect any file descriptor attached as
ancillary data.
Provide a common way to enforce this by adding a accepts_fd boolean in
the message handler structure. When a message handler sets accepts_fd to
true, it is responsible for calling validate_msg_fds with a right
expected file descriptor count.
This will avoid leaking some file descriptor by mistake when adding
support for new vhost user message types.

Signed-off-by: David Marchand <david.marchand@redhat.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
index 17cfeafa1637a3aaf49cd24722bb38a48c291d0a..850848c269c79c213ba45b3e939e63b5828f281f 100644 (file)
--- a/lib/vhost/vhost_user.c
+++ b/lib/vhost/vhost_user.c
@@ -60,6 +60,7 @@ typedef struct vhost_message_handler {
        const char *description;
        int (*callback)(struct virtio_net **pdev, struct vhu_msg_context *ctx,
                int main_fd);
+       bool accepts_fd;
 } vhost_message_handler_t;
 static vhost_message_handler_t vhost_message_handlers[];
 
@@ -262,28 +263,20 @@ vhost_user_notify_queue_state(struct virtio_net *dev, uint16_t index,
  * the device hasn't been initialised.
  */
 static int
-vhost_user_set_owner(struct virtio_net **pdev,
-                       struct vhu_msg_context *ctx,
+vhost_user_set_owner(struct virtio_net **pdev __rte_unused,
+                       struct vhu_msg_context *ctx __rte_unused,
                        int main_fd __rte_unused)
 {
-       struct virtio_net *dev = *pdev;
-
-       if (validate_msg_fds(dev, ctx, 0) != 0)
-               return RTE_VHOST_MSG_RESULT_ERR;
-
        return RTE_VHOST_MSG_RESULT_OK;
 }
 
 static int
 vhost_user_reset_owner(struct virtio_net **pdev,
-                       struct vhu_msg_context *ctx,
+                       struct vhu_msg_context *ctx __rte_unused,
                        int main_fd __rte_unused)
 {
        struct virtio_net *dev = *pdev;
 
-       if (validate_msg_fds(dev, ctx, 0) != 0)
-               return RTE_VHOST_MSG_RESULT_ERR;
-
        vhost_destroy_device_notify(dev);
 
        cleanup_device(dev, 0);
@@ -302,9 +295,6 @@ vhost_user_get_features(struct virtio_net **pdev,
        struct virtio_net *dev = *pdev;
        uint64_t features = 0;
 
-       if (validate_msg_fds(dev, ctx, 0) != 0)
-               return RTE_VHOST_MSG_RESULT_ERR;
-
        rte_vhost_driver_get_features(dev->ifname, &features);
 
        ctx->msg.payload.u64 = features;
@@ -325,9 +315,6 @@ vhost_user_get_queue_num(struct virtio_net **pdev,
        struct virtio_net *dev = *pdev;
        uint32_t queue_num = 0;
 
-       if (validate_msg_fds(dev, ctx, 0) != 0)
-               return RTE_VHOST_MSG_RESULT_ERR;
-
        rte_vhost_driver_get_queue_num(dev->ifname, &queue_num);
 
        ctx->msg.payload.u64 = (uint64_t)queue_num;
@@ -350,9 +337,6 @@ vhost_user_set_features(struct virtio_net **pdev,
        uint64_t vhost_features = 0;
        struct rte_vdpa_device *vdpa_dev;
 
-       if (validate_msg_fds(dev, ctx, 0) != 0)
-               return RTE_VHOST_MSG_RESULT_ERR;
-
        rte_vhost_driver_get_features(dev->ifname, &vhost_features);
        if (features & ~vhost_features) {
                VHOST_LOG_CONFIG(ERR, "(%s) received invalid negotiated features.\n",
@@ -438,9 +422,6 @@ vhost_user_set_vring_num(struct virtio_net **pdev,
        struct virtio_net *dev = *pdev;
        struct vhost_virtqueue *vq = dev->virtqueue[ctx->msg.payload.state.index];
 
-       if (validate_msg_fds(dev, ctx, 0) != 0)
-               return RTE_VHOST_MSG_RESULT_ERR;
-
        if (ctx->msg.payload.state.num > 32768) {
                VHOST_LOG_CONFIG(ERR, "(%s) invalid virtqueue size %u\n",
                                dev->ifname, ctx->msg.payload.state.num);
@@ -882,9 +863,6 @@ vhost_user_set_vring_addr(struct virtio_net **pdev,
        struct vhost_vring_addr *addr = &ctx->msg.payload.addr;
        bool access_ok;
 
-       if (validate_msg_fds(dev, ctx, 0) != 0)
-               return RTE_VHOST_MSG_RESULT_ERR;
-
        if (dev->mem == NULL)
                return RTE_VHOST_MSG_RESULT_ERR;
 
@@ -926,9 +904,6 @@ vhost_user_set_vring_base(struct virtio_net **pdev,
        struct vhost_virtqueue *vq = dev->virtqueue[ctx->msg.payload.state.index];
        uint64_t val = ctx->msg.payload.state.num;
 
-       if (validate_msg_fds(dev, ctx, 0) != 0)
-               return RTE_VHOST_MSG_RESULT_ERR;
-
        if (vq_is_packed(dev)) {
                /*
                 * Bit[0:14]: avail index
@@ -1574,9 +1549,6 @@ vhost_user_get_inflight_fd(struct virtio_net **pdev,
        int numa_node = SOCKET_ID_ANY;
        void *addr;
 
-       if (validate_msg_fds(dev, ctx, 0) != 0)
-               return RTE_VHOST_MSG_RESULT_ERR;
-
        if (ctx->msg.size != sizeof(ctx->msg.payload.inflight)) {
                VHOST_LOG_CONFIG(ERR, "(%s) invalid get_inflight_fd message size is %d\n",
                        dev->ifname, ctx->msg.size);
@@ -2097,9 +2069,6 @@ vhost_user_get_vring_base(struct virtio_net **pdev,
        struct vhost_virtqueue *vq = dev->virtqueue[ctx->msg.payload.state.index];
        uint64_t val;
 
-       if (validate_msg_fds(dev, ctx, 0) != 0)
-               return RTE_VHOST_MSG_RESULT_ERR;
-
        /* We have to stop the queue (virtio) if it is running. */
        vhost_destroy_device_notify(dev);
 
@@ -2176,9 +2145,6 @@ vhost_user_set_vring_enable(struct virtio_net **pdev,
        bool enable = !!ctx->msg.payload.state.num;
        int index = (int)ctx->msg.payload.state.index;
 
-       if (validate_msg_fds(dev, ctx, 0) != 0)
-               return RTE_VHOST_MSG_RESULT_ERR;
-
        VHOST_LOG_CONFIG(INFO, "(%s) set queue enable: %d to qp idx: %d\n",
                        dev->ifname, enable, index);
 
@@ -2204,9 +2170,6 @@ vhost_user_get_protocol_features(struct virtio_net **pdev,
        struct virtio_net *dev = *pdev;
        uint64_t features, protocol_features;
 
-       if (validate_msg_fds(dev, ctx, 0) != 0)
-               return RTE_VHOST_MSG_RESULT_ERR;
-
        rte_vhost_driver_get_features(dev->ifname, &features);
        rte_vhost_driver_get_protocol_features(dev->ifname, &protocol_features);
 
@@ -2226,9 +2189,6 @@ vhost_user_set_protocol_features(struct virtio_net **pdev,
        uint64_t protocol_features = ctx->msg.payload.u64;
        uint64_t slave_protocol_features = 0;
 
-       if (validate_msg_fds(dev, ctx, 0) != 0)
-               return RTE_VHOST_MSG_RESULT_ERR;
-
        rte_vhost_driver_get_protocol_features(dev->ifname,
                        &slave_protocol_features);
        if (protocol_features & ~slave_protocol_features) {
@@ -2368,9 +2328,6 @@ vhost_user_send_rarp(struct virtio_net **pdev,
        uint8_t *mac = (uint8_t *)&ctx->msg.payload.u64;
        struct rte_vdpa_device *vdpa_dev;
 
-       if (validate_msg_fds(dev, ctx, 0) != 0)
-               return RTE_VHOST_MSG_RESULT_ERR;
-
        VHOST_LOG_CONFIG(DEBUG, "(%s) MAC: " RTE_ETHER_ADDR_PRT_FMT "\n",
                dev->ifname, mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
        memcpy(dev->mac.addr_bytes, mac, 6);
@@ -2397,9 +2354,6 @@ vhost_user_net_set_mtu(struct virtio_net **pdev,
 {
        struct virtio_net *dev = *pdev;
 
-       if (validate_msg_fds(dev, ctx, 0) != 0)
-               return RTE_VHOST_MSG_RESULT_ERR;
-
        if (ctx->msg.payload.u64 < VIRTIO_MIN_MTU ||
                        ctx->msg.payload.u64 > VIRTIO_MAX_MTU) {
                VHOST_LOG_CONFIG(ERR, "(%s) invalid MTU size (%"PRIu64")\n",
@@ -2523,9 +2477,6 @@ vhost_user_iotlb_msg(struct virtio_net **pdev,
        uint16_t i;
        uint64_t vva, len;
 
-       if (validate_msg_fds(dev, ctx, 0) != 0)
-               return RTE_VHOST_MSG_RESULT_ERR;
-
        switch (imsg->type) {
        case VHOST_IOTLB_UPDATE:
                len = imsg->size;
@@ -2584,9 +2535,6 @@ vhost_user_set_postcopy_advise(struct virtio_net **pdev,
 #ifdef RTE_LIBRTE_VHOST_POSTCOPY
        struct uffdio_api api_struct;
 
-       if (validate_msg_fds(dev, ctx, 0) != 0)
-               return RTE_VHOST_MSG_RESULT_ERR;
-
        dev->postcopy_ufd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK);
 
        if (dev->postcopy_ufd == -1) {
@@ -2622,9 +2570,6 @@ vhost_user_set_postcopy_listen(struct virtio_net **pdev,
 {
        struct virtio_net *dev = *pdev;
 
-       if (validate_msg_fds(dev, ctx, 0) != 0)
-               return RTE_VHOST_MSG_RESULT_ERR;
-
        if (dev->mem && dev->mem->nregions) {
                VHOST_LOG_CONFIG(ERR, "(%s) regions already registered at postcopy-listen\n",
                                dev->ifname);
@@ -2642,9 +2587,6 @@ vhost_user_postcopy_end(struct virtio_net **pdev,
 {
        struct virtio_net *dev = *pdev;
 
-       if (validate_msg_fds(dev, ctx, 0) != 0)
-               return RTE_VHOST_MSG_RESULT_ERR;
-
        dev->postcopy_listening = 0;
        if (dev->postcopy_ufd >= 0) {
                close(dev->postcopy_ufd);
@@ -2665,9 +2607,6 @@ vhost_user_get_status(struct virtio_net **pdev,
 {
        struct virtio_net *dev = *pdev;
 
-       if (validate_msg_fds(dev, ctx, 0) != 0)
-               return RTE_VHOST_MSG_RESULT_ERR;
-
        ctx->msg.payload.u64 = dev->status;
        ctx->msg.size = sizeof(ctx->msg.payload.u64);
        ctx->fd_num = 0;
@@ -2682,9 +2621,6 @@ vhost_user_set_status(struct virtio_net **pdev,
 {
        struct virtio_net *dev = *pdev;
 
-       if (validate_msg_fds(dev, ctx, 0) != 0)
-               return RTE_VHOST_MSG_RESULT_ERR;
-
        /* As per Virtio specification, the device status is 8bits long */
        if (ctx->msg.payload.u64 > UINT8_MAX) {
                VHOST_LOG_CONFIG(ERR, "(%s) invalid VHOST_USER_SET_STATUS payload 0x%" PRIx64 "\n",
@@ -2727,39 +2663,39 @@ vhost_user_set_status(struct virtio_net **pdev,
 }
 
 #define VHOST_MESSAGE_HANDLERS \
-VHOST_MESSAGE_HANDLER(VHOST_USER_NONE, NULL) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_GET_FEATURES, vhost_user_get_features) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_SET_FEATURES, vhost_user_set_features) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_SET_OWNER, vhost_user_set_owner) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_RESET_OWNER, vhost_user_reset_owner) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_SET_MEM_TABLE, vhost_user_set_mem_table) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_SET_LOG_BASE, vhost_user_set_log_base) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_SET_LOG_FD, vhost_user_set_log_fd) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_SET_VRING_NUM, vhost_user_set_vring_num) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_SET_VRING_ADDR, vhost_user_set_vring_addr) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_SET_VRING_BASE, vhost_user_set_vring_base) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_GET_VRING_BASE, vhost_user_get_vring_base) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_SET_VRING_KICK, vhost_user_set_vring_kick) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_SET_VRING_CALL, vhost_user_set_vring_call) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_SET_VRING_ERR, vhost_user_set_vring_err) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_GET_PROTOCOL_FEATURES, vhost_user_get_protocol_features) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_SET_PROTOCOL_FEATURES, vhost_user_set_protocol_features) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_GET_QUEUE_NUM, vhost_user_get_queue_num) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_SET_VRING_ENABLE, vhost_user_set_vring_enable) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_SEND_RARP, vhost_user_send_rarp) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_NET_SET_MTU, vhost_user_net_set_mtu) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_SET_SLAVE_REQ_FD, vhost_user_set_req_fd) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_IOTLB_MSG, vhost_user_iotlb_msg) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_POSTCOPY_ADVISE, vhost_user_set_postcopy_advise) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_POSTCOPY_LISTEN, vhost_user_set_postcopy_listen) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_POSTCOPY_END, vhost_user_postcopy_end) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_GET_INFLIGHT_FD, vhost_user_get_inflight_fd) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_SET_INFLIGHT_FD, vhost_user_set_inflight_fd) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_SET_STATUS, vhost_user_set_status) \
-VHOST_MESSAGE_HANDLER(VHOST_USER_GET_STATUS, vhost_user_get_status)
-
-#define VHOST_MESSAGE_HANDLER(id, handler) \
-       [id] = { #id, handler },
+VHOST_MESSAGE_HANDLER(VHOST_USER_NONE, NULL, false) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_GET_FEATURES, vhost_user_get_features, false) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_SET_FEATURES, vhost_user_set_features, false) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_SET_OWNER, vhost_user_set_owner, false) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_RESET_OWNER, vhost_user_reset_owner, false) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_SET_MEM_TABLE, vhost_user_set_mem_table, true) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_SET_LOG_BASE, vhost_user_set_log_base, true) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_SET_LOG_FD, vhost_user_set_log_fd, true) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_SET_VRING_NUM, vhost_user_set_vring_num, false) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_SET_VRING_ADDR, vhost_user_set_vring_addr, false) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_SET_VRING_BASE, vhost_user_set_vring_base, false) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_GET_VRING_BASE, vhost_user_get_vring_base, false) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_SET_VRING_KICK, vhost_user_set_vring_kick, true) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_SET_VRING_CALL, vhost_user_set_vring_call, true) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_SET_VRING_ERR, vhost_user_set_vring_err, true) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_GET_PROTOCOL_FEATURES, vhost_user_get_protocol_features, false) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_SET_PROTOCOL_FEATURES, vhost_user_set_protocol_features, false) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_GET_QUEUE_NUM, vhost_user_get_queue_num, false) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_SET_VRING_ENABLE, vhost_user_set_vring_enable, false) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_SEND_RARP, vhost_user_send_rarp, false) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_NET_SET_MTU, vhost_user_net_set_mtu, false) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_SET_SLAVE_REQ_FD, vhost_user_set_req_fd, true) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_IOTLB_MSG, vhost_user_iotlb_msg, false) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_POSTCOPY_ADVISE, vhost_user_set_postcopy_advise, false) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_POSTCOPY_LISTEN, vhost_user_set_postcopy_listen, false) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_POSTCOPY_END, vhost_user_postcopy_end, false) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_GET_INFLIGHT_FD, vhost_user_get_inflight_fd, false) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_SET_INFLIGHT_FD, vhost_user_set_inflight_fd, true) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_SET_STATUS, vhost_user_set_status, false) \
+VHOST_MESSAGE_HANDLER(VHOST_USER_GET_STATUS, vhost_user_get_status, false)
+
+#define VHOST_MESSAGE_HANDLER(id, handler, accepts_fd) \
+       [id] = { #id, handler, accepts_fd },
 static vhost_message_handler_t vhost_message_handlers[] = {
        VHOST_MESSAGE_HANDLERS
 };
@@ -3030,7 +2966,12 @@ vhost_user_msg_handler(int vid, int fd)
        if (msg_handler == NULL || msg_handler->callback == NULL)
                goto skip_to_post_handle;
 
-       ret = msg_handler->callback(&dev, &ctx, fd);
+       if (!msg_handler->accepts_fd && validate_msg_fds(dev, &ctx, 0) != 0) {
+               ret = RTE_VHOST_MSG_RESULT_ERR;
+       } else {
+               ret = msg_handler->callback(&dev, &ctx, fd);
+       }
+
        switch (ret) {
        case RTE_VHOST_MSG_RESULT_ERR:
                VHOST_LOG_CONFIG(ERR, "(%s) processing %s failed.\n",