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