[Qemu-devel] [RFC 18/19] fuzz: Add virtio-net tx and ctrl fuzz targets

[Oleinik, Alexander]

These virtio-net fuzz targets use libqos abstractions to virtio-net
virtqueues.

Signed-off-by: Alexander Oleinik <address@hidden>
---
 tests/fuzz/virtio-net-fuzz.c | 226 +++++++++++++++++++++++++++++++++++
 1 file changed, 226 insertions(+)
 create mode 100644 tests/fuzz/virtio-net-fuzz.c

diff --git a/tests/fuzz/virtio-net-fuzz.c b/tests/fuzz/virtio-net-fuzz.c
new file mode 100644
index 0000000000..4b6c788498
--- /dev/null
+++ b/tests/fuzz/virtio-net-fuzz.c
@@ -0,0 +1,226 @@
+#include "qemu/osdep.h"
+#include "qemu/units.h"
+#include "qapi/error.h"
+#include "qemu-common.h"
+#include "exec/memory.h"
+#include "sysemu/sysemu.h"
+#include "qemu/main-loop.h"
+
+#include "hw/virtio/virtio-net.h"
+#include "hw/virtio/virtio.h"
+#include "tests/libqos/virtio-net.h"
+#include "fuzzer_hooks.h"
+
+#include "fuzz.h"
+#include "qos_fuzz.h"
+
+typedef struct vq_action {
+    uint8_t queue;
+    uint8_t length;
+    uint8_t write;
+    uint8_t next;
+    bool kick;
+} vq_action;
+
+static void virtio_net_ctrl_fuzz(const unsigned char *Data, size_t Size)
+{
+    uint64_t req_addr[10];
+    int reqi =0;
+    uint32_t free_head;
+
+    QGuestAllocator *t_alloc = qos_alloc;
+
+    QVirtioNet *net_if = qos_obj;
+    QVirtioDevice *dev = net_if->vdev;
+    QVirtQueue *q;
+    vq_action vqa;
+    int iters=0;
+    while(true) {
+        if(Size < sizeof(vqa)) {
+            break;
+        }
+        vqa = *((vq_action*)Data);
+        Data += sizeof(vqa);
+        Size -= sizeof(vqa);
+
+        q = net_if->queues[2];
+
+        vqa.length = vqa.length >= Size ? Size :  vqa.length;
+
+        req_addr[reqi] = guest_alloc(t_alloc, vqa.length);
+        memwrite(req_addr[reqi], Data, vqa.length);
+        if(iters == 0)
+            free_head = qvirtqueue_add(q, req_addr[reqi], vqa.length, 
vqa.write , vqa.next) ;
+        else
+            qvirtqueue_add(q, req_addr[reqi], vqa.length, vqa.write , 
vqa.next) ;
+        iters++;
+        reqi++;
+        if(iters==10)
+            break;
+        Data += vqa.length;
+        Size -= vqa.length;
+    }
+    if(iters){
+        qvirtqueue_kick(dev, q, free_head);
+        qtest_clock_step_next(s);
+        main_loop_wait(false);
+        for(int i =0; i<reqi; i++)
+            guest_free(t_alloc, req_addr[i]);
+    }
+    qtest_clear_rxbuf(s);
+    qos_object_queue_destroy(qos_obj);
+}
+
+static void virtio_net_ctrl_fuzz_multi(const unsigned char *Data, size_t Size)
+{
+    uint64_t req_addr[10];
+    int reqi =0;
+    uint32_t free_head;
+
+    QGuestAllocator *t_alloc = qos_alloc;
+
+    QVirtioNet *net_if = qos_obj;
+    QVirtioDevice *dev = net_if->vdev;
+    QVirtQueue *q;
+    vq_action vqa;
+    int iters=0;
+    while(Size >= sizeof(vqa)) {
+        vqa = *((vq_action*)Data);
+        Data += sizeof(vqa);
+        Size -= sizeof(vqa);
+        if(vqa.kick && free_head)
+        {
+            qvirtqueue_kick(dev, q, free_head);
+            qtest_clock_step_next(s);
+            main_loop_wait(false);
+            for(int i =0; i<reqi; i++)
+                guest_free(t_alloc, req_addr[i]);
+            reqi = 0;
+        }
+        else {
+            q = net_if->queues[2];
+
+            vqa.length = vqa.length >= Size ? Size :  vqa.length;
+
+            req_addr[reqi] = guest_alloc(t_alloc, vqa.length);
+            memwrite(req_addr[reqi], Data, vqa.length);
+            if(iters == 0)
+                free_head = qvirtqueue_add(q, req_addr[reqi], vqa.length, 
vqa.write , vqa.next) ;
+            else
+                qvirtqueue_add(q, req_addr[reqi], vqa.length, vqa.write , 
vqa.next) ;
+            iters++;
+            reqi++;
+            if(iters==10)
+                break;
+            Data += vqa.length;
+            Size -= vqa.length;
+        }
+    }
+    qtest_clear_rxbuf(s);
+    qos_object_queue_destroy(qos_obj);
+}
+
+int *sv;
+static void virtio_net_tx_fuzz(const unsigned char *Data, size_t Size)
+{
+    uint64_t req_addr[10];
+    int reqi =0;
+    uint32_t free_head;
+
+    QGuestAllocator *t_alloc = qos_alloc;
+
+    QVirtioNet *net_if = qos_obj;
+    QVirtioDevice *dev = net_if->vdev;
+    QVirtQueue *q;
+    vq_action vqa;
+    int iters=0;
+    while(true) {
+        if(Size < sizeof(vqa)) {
+            break;
+        }
+        vqa = *((vq_action*)Data);
+        Data += sizeof(vqa);
+        Size -= sizeof(vqa);
+
+        q = net_if->queues[1];
+
+        vqa.length = vqa.length >= Size ? Size :  vqa.length;
+
+        req_addr[reqi] = guest_alloc(t_alloc, vqa.length);
+        memwrite(req_addr[reqi], Data, vqa.length);
+        if(iters == 0)
+            free_head = qvirtqueue_add(q, req_addr[reqi], vqa.length, 
vqa.write , vqa.next) ;
+        else
+            qvirtqueue_add(q, req_addr[reqi], vqa.length, vqa.write , 
vqa.next) ;
+        iters++;
+        reqi++;
+        if(iters==10)
+            break;
+        Data += vqa.length;
+        Size -= vqa.length;
+    }
+    if(iters){
+        qvirtqueue_kick(dev, q, free_head);
+        qtest_clock_step_next(s);
+        main_loop_wait(false);
+        for(int i =0; i<reqi; i++)
+            guest_free(t_alloc, req_addr[i]);
+    }
+    qtest_clear_rxbuf(s);
+    qos_object_queue_destroy(qos_obj);
+}
+
+static void *virtio_net_test_setup_socket(GString *cmd_line, void *arg)
+{
+    if(!sv){
+        sv = g_new(int, 2);
+        int ret = socketpair(PF_UNIX, SOCK_STREAM, 0, sv);
+        fcntl(sv[0], F_SETFL, O_NONBLOCK);
+        g_assert_cmpint(ret, !=, -1);
+    }
+    g_string_append_printf(cmd_line, " -netdev socket,fd=%d,id=hs0 ", sv[1]);
+    return arg;
+}
+
+static void fuzz_fork(const unsigned char *Data, size_t Size){
+    if (fork() == 0) {
+        virtio_net_ctrl_fuzz(Data, Size);
+        counter_shm_store();
+        _Exit(0);
+    } 
+    else {
+        wait(NULL);
+        counter_shm_load();
+    }
+}
+
+static void fork_pre_main(void) {
+    qos_setup();
+    counter_shm_init();
+}
+
+static void register_virtio_net_fuzz_targets(void)
+{
+    QOSGraphTestOptions opts = {
+        .before = virtio_net_test_setup_socket,
+    };
+    fuzz_add_qos_target("virtio-net-ctrl-fuzz", "virtio-net ctrl virtqueue 
fuzzer",
+            "virtio-net", &opts, &qos_setup, NULL, NULL, &reboot,
+            &qos_init_path, &virtio_net_ctrl_fuzz, NULL);
+
+    fuzz_add_qos_target("virtio-net-ctrl-multi-fuzz", "virtio-net ctrl 
virtqueue \
+            fuzzer with multiple kicks",
+            "virtio-net", &opts, &qos_setup, NULL, NULL, &reboot,
+            &qos_init_path, &virtio_net_ctrl_fuzz_multi, NULL);
+
+    fuzz_add_qos_target("virtio-net-tx-fuzz", "virtio-net tx virtqueue fuzzer",
+            "virtio-net", &opts, &qos_setup, NULL, NULL, &reboot,
+            &qos_init_path, &virtio_net_tx_fuzz, NULL);
+
+    // TODO: This doesn't work. Possibly due to threading..
+    fuzz_add_qos_target("virtio-net-fork", "virtio-net tx virtqueue",
+            "virtio-net", &opts, &fork_pre_main, &qos_init_path, NULL, NULL,
+            NULL, &fuzz_fork, NULL);
+}
+
+fuzz_target_init(register_virtio_net_fuzz_targets);
-- 
2.20.1