1 /* 2 * Copyright (c) 2015 FUJITSU LIMITED 3 * Author: Yang Hongyang <yanghy@cn.fujitsu.com> 4 * 5 * This work is licensed under the terms of the GNU GPL, version 2 or 6 * later. See the COPYING file in the top-level directory. 7 */ 8 9 #include "qemu/osdep.h" 10 #include "net/filter.h" 11 #include "net/queue.h" 12 #include "qemu-common.h" 13 #include "qemu/timer.h" 14 #include "qemu/iov.h" 15 #include "qapi/qmp/qerror.h" 16 #include "qapi-visit.h" 17 #include "qom/object.h" 18 19 #define TYPE_FILTER_BUFFER "filter-buffer" 20 21 #define FILTER_BUFFER(obj) \ 22 OBJECT_CHECK(FilterBufferState, (obj), TYPE_FILTER_BUFFER) 23 24 typedef struct FilterBufferState { 25 NetFilterState parent_obj; 26 27 NetQueue *incoming_queue; 28 uint32_t interval; 29 QEMUTimer release_timer; 30 } FilterBufferState; 31 32 static void filter_buffer_flush(NetFilterState *nf) 33 { 34 FilterBufferState *s = FILTER_BUFFER(nf); 35 36 if (!qemu_net_queue_flush(s->incoming_queue)) { 37 /* Unable to empty the queue, purge remaining packets */ 38 qemu_net_queue_purge(s->incoming_queue, nf->netdev); 39 } 40 } 41 42 static void filter_buffer_release_timer(void *opaque) 43 { 44 NetFilterState *nf = opaque; 45 FilterBufferState *s = FILTER_BUFFER(nf); 46 47 /* 48 * Note: filter_buffer_flush() drops packets that can't be sent 49 * TODO: We should leave them queued. But currently there's no way 50 * for the next filter or receiver to notify us that it can receive 51 * more packets. 52 */ 53 filter_buffer_flush(nf); 54 /* Timer rearmed to fire again in s->interval microseconds. */ 55 timer_mod(&s->release_timer, 56 qemu_clock_get_us(QEMU_CLOCK_VIRTUAL) + s->interval); 57 } 58 59 /* filter APIs */ 60 static ssize_t filter_buffer_receive_iov(NetFilterState *nf, 61 NetClientState *sender, 62 unsigned flags, 63 const struct iovec *iov, 64 int iovcnt, 65 NetPacketSent *sent_cb) 66 { 67 FilterBufferState *s = FILTER_BUFFER(nf); 68 69 /* 70 * We return size when buffer a packet, the sender will take it as 71 * a already sent packet, so sent_cb should not be called later. 72 * 73 * FIXME: Even if the guest can't receive packets for some reasons, 74 * the filter can still accept packets until its internal queue is full. 75 * For example: 76 * For some reason, receiver could not receive more packets 77 * (.can_receive() returns zero). Without a filter, at most one packet 78 * will be queued in incoming queue and sender's poll will be disabled 79 * unit its sent_cb() was called. With a filter, it will keep receiving 80 * the packets without caring about the receiver. This is suboptimal. 81 * May need more thoughts (e.g keeping sent_cb). 82 */ 83 qemu_net_queue_append_iov(s->incoming_queue, sender, flags, 84 iov, iovcnt, NULL); 85 return iov_size(iov, iovcnt); 86 } 87 88 static void filter_buffer_cleanup(NetFilterState *nf) 89 { 90 FilterBufferState *s = FILTER_BUFFER(nf); 91 92 if (s->interval) { 93 timer_del(&s->release_timer); 94 } 95 96 /* flush packets */ 97 if (s->incoming_queue) { 98 filter_buffer_flush(nf); 99 g_free(s->incoming_queue); 100 } 101 } 102 103 static void filter_buffer_setup(NetFilterState *nf, Error **errp) 104 { 105 FilterBufferState *s = FILTER_BUFFER(nf); 106 107 /* 108 * We may want to accept zero interval when VM FT solutions like MC 109 * or COLO use this filter to release packets on demand. 110 */ 111 if (!s->interval) { 112 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "interval", 113 "a non-zero interval"); 114 return; 115 } 116 117 s->incoming_queue = qemu_new_net_queue(qemu_netfilter_pass_to_next, nf); 118 if (s->interval) { 119 timer_init_us(&s->release_timer, QEMU_CLOCK_VIRTUAL, 120 filter_buffer_release_timer, nf); 121 /* Timer armed to fire in s->interval microseconds. */ 122 timer_mod(&s->release_timer, 123 qemu_clock_get_us(QEMU_CLOCK_VIRTUAL) + s->interval); 124 } 125 } 126 127 static void filter_buffer_class_init(ObjectClass *oc, void *data) 128 { 129 NetFilterClass *nfc = NETFILTER_CLASS(oc); 130 131 nfc->setup = filter_buffer_setup; 132 nfc->cleanup = filter_buffer_cleanup; 133 nfc->receive_iov = filter_buffer_receive_iov; 134 } 135 136 static void filter_buffer_get_interval(Object *obj, Visitor *v, void *opaque, 137 const char *name, Error **errp) 138 { 139 FilterBufferState *s = FILTER_BUFFER(obj); 140 uint32_t value = s->interval; 141 142 visit_type_uint32(v, &value, name, errp); 143 } 144 145 static void filter_buffer_set_interval(Object *obj, Visitor *v, void *opaque, 146 const char *name, Error **errp) 147 { 148 FilterBufferState *s = FILTER_BUFFER(obj); 149 Error *local_err = NULL; 150 uint32_t value; 151 152 visit_type_uint32(v, &value, name, &local_err); 153 if (local_err) { 154 goto out; 155 } 156 if (!value) { 157 error_setg(&local_err, "Property '%s.%s' requires a positive value", 158 object_get_typename(obj), name); 159 goto out; 160 } 161 s->interval = value; 162 163 out: 164 error_propagate(errp, local_err); 165 } 166 167 static void filter_buffer_init(Object *obj) 168 { 169 object_property_add(obj, "interval", "int", 170 filter_buffer_get_interval, 171 filter_buffer_set_interval, NULL, NULL, NULL); 172 } 173 174 static const TypeInfo filter_buffer_info = { 175 .name = TYPE_FILTER_BUFFER, 176 .parent = TYPE_NETFILTER, 177 .class_init = filter_buffer_class_init, 178 .instance_init = filter_buffer_init, 179 .instance_size = sizeof(FilterBufferState), 180 }; 181 182 static void register_types(void) 183 { 184 type_register_static(&filter_buffer_info); 185 } 186 187 type_init(register_types); 188