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 "qapi/error.h" 13 #include "qemu-common.h" 14 #include "qemu/timer.h" 15 #include "qemu/iov.h" 16 #include "qapi/qapi-builtin-visit.h" 17 #include "qapi/qmp/qerror.h" 18 #include "qom/object.h" 19 20 #define TYPE_FILTER_BUFFER "filter-buffer" 21 22 #define FILTER_BUFFER(obj) \ 23 OBJECT_CHECK(FilterBufferState, (obj), TYPE_FILTER_BUFFER) 24 25 typedef struct FilterBufferState { 26 NetFilterState parent_obj; 27 28 NetQueue *incoming_queue; 29 uint32_t interval; 30 QEMUTimer release_timer; 31 } FilterBufferState; 32 33 static void filter_buffer_flush(NetFilterState *nf) 34 { 35 FilterBufferState *s = FILTER_BUFFER(nf); 36 37 if (!qemu_net_queue_flush(s->incoming_queue)) { 38 /* Unable to empty the queue, purge remaining packets */ 39 qemu_net_queue_purge(s->incoming_queue, nf->netdev); 40 } 41 } 42 43 static void filter_buffer_release_timer(void *opaque) 44 { 45 NetFilterState *nf = opaque; 46 FilterBufferState *s = FILTER_BUFFER(nf); 47 48 /* 49 * Note: filter_buffer_flush() drops packets that can't be sent 50 * TODO: We should leave them queued. But currently there's no way 51 * for the next filter or receiver to notify us that it can receive 52 * more packets. 53 */ 54 filter_buffer_flush(nf); 55 /* Timer rearmed to fire again in s->interval microseconds. */ 56 timer_mod(&s->release_timer, 57 qemu_clock_get_us(QEMU_CLOCK_VIRTUAL) + s->interval); 58 } 59 60 /* filter APIs */ 61 static ssize_t filter_buffer_receive_iov(NetFilterState *nf, 62 NetClientState *sender, 63 unsigned flags, 64 const struct iovec *iov, 65 int iovcnt, 66 NetPacketSent *sent_cb) 67 { 68 FilterBufferState *s = FILTER_BUFFER(nf); 69 70 /* 71 * We return size when buffer a packet, the sender will take it as 72 * a already sent packet, so sent_cb should not be called later. 73 * 74 * FIXME: Even if the guest can't receive packets for some reasons, 75 * the filter can still accept packets until its internal queue is full. 76 * For example: 77 * For some reason, receiver could not receive more packets 78 * (.can_receive() returns zero). Without a filter, at most one packet 79 * will be queued in incoming queue and sender's poll will be disabled 80 * unit its sent_cb() was called. With a filter, it will keep receiving 81 * the packets without caring about the receiver. This is suboptimal. 82 * May need more thoughts (e.g keeping sent_cb). 83 */ 84 qemu_net_queue_append_iov(s->incoming_queue, sender, flags, 85 iov, iovcnt, NULL); 86 return iov_size(iov, iovcnt); 87 } 88 89 static void filter_buffer_cleanup(NetFilterState *nf) 90 { 91 FilterBufferState *s = FILTER_BUFFER(nf); 92 93 if (s->interval) { 94 timer_del(&s->release_timer); 95 } 96 97 /* flush packets */ 98 if (s->incoming_queue) { 99 filter_buffer_flush(nf); 100 g_free(s->incoming_queue); 101 } 102 } 103 104 static void filter_buffer_setup_timer(NetFilterState *nf) 105 { 106 FilterBufferState *s = FILTER_BUFFER(nf); 107 108 if (s->interval) { 109 timer_init_us(&s->release_timer, QEMU_CLOCK_VIRTUAL, 110 filter_buffer_release_timer, nf); 111 /* Timer armed to fire in s->interval microseconds. */ 112 timer_mod(&s->release_timer, 113 qemu_clock_get_us(QEMU_CLOCK_VIRTUAL) + s->interval); 114 } 115 } 116 117 static void filter_buffer_setup(NetFilterState *nf, Error **errp) 118 { 119 FilterBufferState *s = FILTER_BUFFER(nf); 120 121 /* 122 * We may want to accept zero interval when VM FT solutions like MC 123 * or COLO use this filter to release packets on demand. 124 */ 125 if (!s->interval) { 126 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "interval", 127 "a non-zero interval"); 128 return; 129 } 130 131 s->incoming_queue = qemu_new_net_queue(qemu_netfilter_pass_to_next, nf); 132 filter_buffer_setup_timer(nf); 133 } 134 135 static void filter_buffer_status_changed(NetFilterState *nf, Error **errp) 136 { 137 FilterBufferState *s = FILTER_BUFFER(nf); 138 139 if (!nf->on) { 140 if (s->interval) { 141 timer_del(&s->release_timer); 142 } 143 filter_buffer_flush(nf); 144 } else { 145 filter_buffer_setup_timer(nf); 146 } 147 } 148 149 static void filter_buffer_class_init(ObjectClass *oc, void *data) 150 { 151 NetFilterClass *nfc = NETFILTER_CLASS(oc); 152 153 nfc->setup = filter_buffer_setup; 154 nfc->cleanup = filter_buffer_cleanup; 155 nfc->receive_iov = filter_buffer_receive_iov; 156 nfc->status_changed = filter_buffer_status_changed; 157 } 158 159 static void filter_buffer_get_interval(Object *obj, Visitor *v, 160 const char *name, void *opaque, 161 Error **errp) 162 { 163 FilterBufferState *s = FILTER_BUFFER(obj); 164 uint32_t value = s->interval; 165 166 visit_type_uint32(v, name, &value, errp); 167 } 168 169 static void filter_buffer_set_interval(Object *obj, Visitor *v, 170 const char *name, void *opaque, 171 Error **errp) 172 { 173 FilterBufferState *s = FILTER_BUFFER(obj); 174 Error *local_err = NULL; 175 uint32_t value; 176 177 visit_type_uint32(v, name, &value, &local_err); 178 if (local_err) { 179 goto out; 180 } 181 if (!value) { 182 error_setg(&local_err, "Property '%s.%s' requires a positive value", 183 object_get_typename(obj), name); 184 goto out; 185 } 186 s->interval = value; 187 188 out: 189 error_propagate(errp, local_err); 190 } 191 192 static void filter_buffer_init(Object *obj) 193 { 194 object_property_add(obj, "interval", "uint32", 195 filter_buffer_get_interval, 196 filter_buffer_set_interval, NULL, NULL, NULL); 197 } 198 199 static const TypeInfo filter_buffer_info = { 200 .name = TYPE_FILTER_BUFFER, 201 .parent = TYPE_NETFILTER, 202 .class_init = filter_buffer_class_init, 203 .instance_init = filter_buffer_init, 204 .instance_size = sizeof(FilterBufferState), 205 }; 206 207 static void register_types(void) 208 { 209 type_register_static(&filter_buffer_info); 210 } 211 212 type_init(register_types); 213