/*
   * Copyright (c) 2017 Pure Storage, Inc.
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   * notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   * notice, this list of conditions and the following disclaimer in the
   * documentation and/or other materials provided with the distribution.
   * 3. The name of the author may not be used to endorse or promote
   * products derived from this software without specific prior written
   * permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #ifdef HAVE_CONFIG_H
  #include "config.h"
  #endif
  
  #include "pcap-int.h"
  #include "pcap-rdmasniff.h"
  
  #include <infiniband/verbs.h>
  #include <stdlib.h>
  #include <string.h>
  #include <sys/time.h>
  
  #if !defined(IBV_FLOW_ATTR_SNIFFER)
  #define IBV_FLOW_ATTR_SNIFFER	3
  #endif
  
  static const int RDMASNIFF_NUM_RECEIVES = 128;
  static const int RDMASNIFF_RECEIVE_SIZE = 10000;
  
  struct pcap_rdmasniff {
  	struct ibv_device *		rdma_device;
  	struct ibv_context *		context;
  	struct ibv_comp_channel *	channel;
  	struct ibv_pd *			pd;
  	struct ibv_cq *			cq;
  	struct ibv_qp *			qp;
  	struct ibv_flow *               flow;
  	struct ibv_mr *			mr;
  	u_char *			oneshot_buffer;
  	unsigned			port_num;
  	int                             cq_event;
  	u_int                           packets_recv;
  };
  
  static int
  rdmasniff_stats(pcap_t *handle, struct pcap_stat *stat)
  {
  	struct pcap_rdmasniff *priv = handle->priv;
  
  	stat->ps_recv = priv->packets_recv;
  	stat->ps_drop = 0;
  	stat->ps_ifdrop = 0;
  
  	return 0;
  }
  
  static void
  rdmasniff_cleanup(pcap_t *handle)
  {
  	struct pcap_rdmasniff *priv = handle->priv;
  
  	ibv_dereg_mr(priv->mr);
  	ibv_destroy_flow(priv->flow);
  	ibv_destroy_qp(priv->qp);
  	ibv_destroy_cq(priv->cq);
  	ibv_dealloc_pd(priv->pd);
  	ibv_destroy_comp_channel(priv->channel);
  	ibv_close_device(priv->context);
  	free(priv->oneshot_buffer);
  
  	pcap_cleanup_live_common(handle);
  }
  
  static void
  rdmasniff_post_recv(pcap_t *handle, uint64_t wr_id)
  {
  	struct pcap_rdmasniff *priv = handle->priv;
  	struct ibv_sge sg_entry;
  	struct ibv_recv_wr wr, *bad_wr;
  
  	sg_entry.length = RDMASNIFF_RECEIVE_SIZE;
  	sg_entry.addr = (uintptr_t) handle->buffer + RDMASNIFF_RECEIVE_SIZE * wr_id;
  	sg_entry.lkey = priv->mr->lkey;
  
  	wr.wr_id = wr_id;
  	wr.num_sge = 1;
  	wr.sg_list = &sg_entry;
  	wr.next = NULL;
  
  	ibv_post_recv(priv->qp, &wr, &bad_wr);
  }
  
  static int
  rdmasniff_read(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user)
  {
  	struct pcap_rdmasniff *priv = handle->priv;
  	struct ibv_cq *ev_cq;
  	void *ev_ctx;
  	struct ibv_wc wc;
  	struct pcap_pkthdr pkth;
  	u_char *pktd;
  	int count = 0;
  
  	if (!priv->cq_event) {
  		while (ibv_get_cq_event(priv->channel, &ev_cq, &ev_ctx) < 0) {
  			if (errno != EINTR) {
  				return PCAP_ERROR;
  			}
  			if (handle->break_loop) {
  				handle->break_loop = 0;
  				return PCAP_ERROR_BREAK;
  			}
  		}
  		ibv_ack_cq_events(priv->cq, 1);
  		ibv_req_notify_cq(priv->cq, 0);
  		priv->cq_event = 1;
  	}
  
  	while (count < max_packets || PACKET_COUNT_IS_UNLIMITED(max_packets)) {
  		if (ibv_poll_cq(priv->cq, 1, &wc) != 1) {
  			priv->cq_event = 0;
  			break;
  		}
  
  		if (wc.status != IBV_WC_SUCCESS) {
  			fprintf(stderr, "failed WC wr_id %lld status %d/%s\n",
  				(unsigned long long) wc.wr_id,
  				wc.status, ibv_wc_status_str(wc.status));
  			continue;
  		}
  
  		pkth.len = wc.byte_len;
  		pkth.caplen = min(pkth.len, (u_int)handle->snapshot);
  		gettimeofday(&pkth.ts, NULL);
  
  		pktd = (u_char *) handle->buffer + wc.wr_id * RDMASNIFF_RECEIVE_SIZE;
  
  		if (handle->fcode.bf_insns == NULL ||
  		    bpf_filter(handle->fcode.bf_insns, pktd, pkth.len, pkth.caplen)) {
  			callback(user, &pkth, pktd);
  			++priv->packets_recv;
  			++count;
  		}
  
  		rdmasniff_post_recv(handle, wc.wr_id);
  
  		if (handle->break_loop) {
  			handle->break_loop = 0;
  			return PCAP_ERROR_BREAK;
  		}
  	}
  
  	return count;
  }
  
  static void
  rdmasniff_oneshot(u_char *user, const struct pcap_pkthdr *h, const u_char *bytes)
  {
  	struct oneshot_userdata *sp = (struct oneshot_userdata *) user;
  	pcap_t *handle = sp->pd;
  	struct pcap_rdmasniff *priv = handle->priv;
  
  	*sp->hdr = *h;
  	memcpy(priv->oneshot_buffer, bytes, h->caplen);
  	*sp->pkt = priv->oneshot_buffer;
  }
  
  static int
  rdmasniff_activate(pcap_t *handle)
  {
  	struct pcap_rdmasniff *priv = handle->priv;
  	struct ibv_qp_init_attr qp_init_attr;
  	struct ibv_qp_attr qp_attr;
  	struct ibv_flow_attr flow_attr;
  	struct ibv_port_attr port_attr;
  	int i;
  
  	priv->context = ibv_open_device(priv->rdma_device);
  	if (!priv->context) {
  		pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
  			      "Failed to open device %s", handle->opt.device);
  		goto error;
  	}
  
  	priv->pd = ibv_alloc_pd(priv->context);
  	if (!priv->pd) {
  		pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
  			      "Failed to alloc PD for device %s", handle->opt.device);
  		goto error;
  	}
  
  	priv->channel = ibv_create_comp_channel(priv->context);
  	if (!priv->channel) {
  		pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
  			      "Failed to create comp channel for device %s", handle->opt.device);
  		goto error;
  	}
  
  	priv->cq = ibv_create_cq(priv->context, RDMASNIFF_NUM_RECEIVES,
  				 NULL, priv->channel, 0);
  	if (!priv->cq) {
  		pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
  			      "Failed to create CQ for device %s", handle->opt.device);
  		goto error;
  	}
  
  	ibv_req_notify_cq(priv->cq, 0);
  
  	memset(&qp_init_attr, 0, sizeof qp_init_attr);
  	qp_init_attr.send_cq = qp_init_attr.recv_cq = priv->cq;
  	qp_init_attr.cap.max_recv_wr = RDMASNIFF_NUM_RECEIVES;
  	qp_init_attr.cap.max_recv_sge = 1;
  	qp_init_attr.qp_type = IBV_QPT_RAW_PACKET;
  	priv->qp = ibv_create_qp(priv->pd, &qp_init_attr);
  	if (!priv->qp) {
  		pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
  			      "Failed to create QP for device %s", handle->opt.device);
  		goto error;
  	}
  
  	memset(&qp_attr, 0, sizeof qp_attr);
  	qp_attr.qp_state = IBV_QPS_INIT;
  	qp_attr.port_num = priv->port_num;
  	if (ibv_modify_qp(priv->qp, &qp_attr, IBV_QP_STATE | IBV_QP_PORT)) {
  		pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
  			      "Failed to modify QP to INIT for device %s", handle->opt.device);
  		goto error;
  	}
  
  	memset(&qp_attr, 0, sizeof qp_attr);
  	qp_attr.qp_state = IBV_QPS_RTR;
  	if (ibv_modify_qp(priv->qp, &qp_attr, IBV_QP_STATE)) {
  		pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
  			      "Failed to modify QP to RTR for device %s", handle->opt.device);
  		goto error;
  	}
  
  	memset(&flow_attr, 0, sizeof flow_attr);
  	flow_attr.type = IBV_FLOW_ATTR_SNIFFER;
  	flow_attr.size = sizeof flow_attr;
  	flow_attr.port = priv->port_num;
  	priv->flow = ibv_create_flow(priv->qp, &flow_attr);
  	if (!priv->flow) {
  		pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
  			      "Failed to create flow for device %s", handle->opt.device);
  		goto error;
  	}
  
  	handle->bufsize = RDMASNIFF_NUM_RECEIVES * RDMASNIFF_RECEIVE_SIZE;
  	handle->buffer = malloc(handle->bufsize);
  	if (!handle->buffer) {
  		pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
  			      "Failed to allocate receive buffer for device %s", handle->opt.device);
  		goto error;
  	}
  
  	priv->oneshot_buffer = malloc(RDMASNIFF_RECEIVE_SIZE);
  	if (!priv->oneshot_buffer) {
  		pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
  			      "Failed to allocate oneshot buffer for device %s", handle->opt.device);
  		goto error;
  	}
  
  	priv->mr = ibv_reg_mr(priv->pd, handle->buffer, handle->bufsize, IBV_ACCESS_LOCAL_WRITE);
  	if (!priv->mr) {
  		pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
  			      "Failed to register MR for device %s", handle->opt.device);
  		goto error;
  	}
  
  
  	for (i = 0; i < RDMASNIFF_NUM_RECEIVES; ++i) {
  		rdmasniff_post_recv(handle, i);
  	}
  
  	if (!ibv_query_port(priv->context, priv->port_num, &port_attr) &&
  	    port_attr.link_layer == IBV_LINK_LAYER_INFINIBAND) {
  		handle->linktype = DLT_INFINIBAND;
  	} else {
  		handle->linktype = DLT_EN10MB;
  	}
  
  	if (handle->snapshot <= 0 || handle->snapshot > RDMASNIFF_RECEIVE_SIZE)
  		handle->snapshot = RDMASNIFF_RECEIVE_SIZE;
  
  	handle->offset = 0;
  	handle->read_op = rdmasniff_read;
  	handle->stats_op = rdmasniff_stats;
  	handle->cleanup_op = rdmasniff_cleanup;
  	handle->setfilter_op = install_bpf_program;
  	handle->setdirection_op = NULL;
  	handle->set_datalink_op = NULL;
  	handle->getnonblock_op = pcap_getnonblock_fd;
  	handle->setnonblock_op = pcap_setnonblock_fd;
  	handle->oneshot_callback = rdmasniff_oneshot;
  	handle->selectable_fd = priv->channel->fd;
  
  	return 0;
  
  error:
  	if (priv->mr) {
  		ibv_dereg_mr(priv->mr);
  	}
  
  	if (priv->flow) {
  		ibv_destroy_flow(priv->flow);
  	}
  
  	if (priv->qp) {
  		ibv_destroy_qp(priv->qp);
  	}
  
  	if (priv->cq) {
  		ibv_destroy_cq(priv->cq);
  	}
  
  	if (priv->channel) {
  		ibv_destroy_comp_channel(priv->channel);
  	}
  
  	if (priv->pd) {
  		ibv_dealloc_pd(priv->pd);
  	}
  
  	if (priv->context) {
  		ibv_close_device(priv->context);
  	}
  
  	if (priv->oneshot_buffer) {
  		free(priv->oneshot_buffer);
  	}
  
  	return PCAP_ERROR;
  }
  
  pcap_t *
  rdmasniff_create(const char *device, char *ebuf, int *is_ours)
  {
  	struct pcap_rdmasniff *priv;
  	struct ibv_device **dev_list;
  	int numdev;
  	size_t namelen;
  	const char *port;
  	unsigned port_num;
  	int i;
  	pcap_t *p = NULL;
  
  	*is_ours = 0;
  
  	dev_list = ibv_get_device_list(&numdev);
  	if (!dev_list || !numdev) {
  		return NULL;
  	}
  
  	namelen = strlen(device);
  
  	port = strchr(device, ':');
  	if (port) {
  		port_num = strtoul(port + 1, NULL, 10);
  		if (port_num > 0) {
  			namelen = port - device;
  		} else {
  			port_num = 1;
  		}
  	} else {
  		port_num = 1;
  	}
  
  	for (i = 0; i < numdev; ++i) {
  		if (strlen(dev_list[i]->name) == namelen &&
  		    !strncmp(device, dev_list[i]->name, namelen)) {
  			*is_ours = 1;
  
  			p = pcap_create_common(ebuf, sizeof (struct pcap_rdmasniff));
  			if (p) {
  				p->activate_op = rdmasniff_activate;
  				priv = p->priv;
  				priv->rdma_device = dev_list[i];
  				priv->port_num = port_num;
  			}
  			break;
  		}
  	}
  
  	ibv_free_device_list(dev_list);
  	return p;
  }
  
  int
  rdmasniff_findalldevs(pcap_if_list_t *devlistp, char *err_str)
  {
  	struct ibv_device **dev_list;
  	int numdev;
  	int i;
  	int ret = 0;
  
  	dev_list = ibv_get_device_list(&numdev);
  	if (!dev_list || !numdev) {
  		return 0;
  	}
  
  	for (i = 0; i < numdev; ++i) {
  		/*
  		 * XXX - do the notions of "up", "running", or
  		 * "connected" apply here?
  		 */
  		if (!add_dev(devlistp, dev_list[i]->name, 0, "RDMA sniffer", err_str)) {
  			ret = -1;
  			goto out;
  		}
  	}
  
  out:
  	ibv_free_device_list(dev_list);
  	return ret;
  }