Re: [dpdk-dev] [PATCH v2] Fix librte_pmd_pcap driver double stop error

["Nicolás Pernas Maradei" <nico@emutex.com>]

Hi,

New in Patch v2:

- Fixes an issue in eth_dev_start/stop where a single interface was 
always opened/closed even though pcap files had been selected for rx/tx 
streams.
- The link_status was not being properly updated in case of using a 
single interface for rx/tx streams.

Nico.

On 2014-10-04 23:24, Nicolás Pernas Maradei wrote:
> From: Nicolás Pernas Maradei <nicolas.pernas.maradei@emutex.com>
> 
> librte_pmd_pcap driver was opening the pcap/interfaces only at init 
> time and
> closing them only when the port was being stopped. This behaviour would 
> cause
> problems (leading to segfault) if the user closed the port 2 times. The 
> first
> time the pcap/interfaces would be normally closed but libpcap would 
> throw an
> error causing a segfault if the closed pcaps/interfaces were closed 
> again.
> This behaviour is solved by re-openning pcaps/interfaces when the port 
> is
> started (only if these weren't open already for example at init time).
> 
> Signed-off-by: Nicolás Pernas Maradei <nico@emutex.com>
> ---
>  lib/librte_pmd_pcap/rte_eth_pcap.c | 271 
> +++++++++++++++++++++++++++++--------
>  1 file changed, 212 insertions(+), 59 deletions(-)
> 
> diff --git a/lib/librte_pmd_pcap/rte_eth_pcap.c
> b/lib/librte_pmd_pcap/rte_eth_pcap.c
> index 19492e8..f12d1e7 100644
> --- a/lib/librte_pmd_pcap/rte_eth_pcap.c
> +++ b/lib/librte_pmd_pcap/rte_eth_pcap.c
> @@ -67,6 +67,8 @@ struct pcap_rx_queue {
>  	struct rte_mempool *mb_pool;
>  	volatile unsigned long rx_pkts;
>  	volatile unsigned long err_pkts;
> +	const char *name;
> +	const char *type;
>  };
> 
>  struct pcap_tx_queue {
> @@ -74,27 +76,32 @@ struct pcap_tx_queue {
>  	pcap_t *pcap;
>  	volatile unsigned long tx_pkts;
>  	volatile unsigned long err_pkts;
> +	const char *name;
> +	const char *type;
>  };
> 
>  struct rx_pcaps {
>  	unsigned num_of_rx;
>  	pcap_t *pcaps[RTE_PMD_RING_MAX_RX_RINGS];
> +	const char *names[RTE_PMD_RING_MAX_RX_RINGS];
> +	const char *types[RTE_PMD_RING_MAX_RX_RINGS];
>  };
> 
>  struct tx_pcaps {
>  	unsigned num_of_tx;
>  	pcap_dumper_t *dumpers[RTE_PMD_RING_MAX_TX_RINGS];
>  	pcap_t *pcaps[RTE_PMD_RING_MAX_RX_RINGS];
> +	const char *names[RTE_PMD_RING_MAX_RX_RINGS];
> +	const char *types[RTE_PMD_RING_MAX_RX_RINGS];
>  };
> 
>  struct pmd_internals {
> +	struct pcap_rx_queue rx_queue[RTE_PMD_RING_MAX_RX_RINGS];
> +	struct pcap_tx_queue tx_queue[RTE_PMD_RING_MAX_TX_RINGS];
>  	unsigned nb_rx_queues;
>  	unsigned nb_tx_queues;
> -
>  	int if_index;
> -
> -	struct pcap_rx_queue rx_queue[RTE_PMD_RING_MAX_RX_RINGS];
> -	struct pcap_tx_queue tx_queue[RTE_PMD_RING_MAX_TX_RINGS];
> +	int single_iface;
>  };
> 
>  const char *valid_arguments[] = {
> @@ -106,6 +113,10 @@ const char *valid_arguments[] = {
>  	NULL
>  };
> 
> +static int open_single_tx_pcap(const char *pcap_filename,
> pcap_dumper_t **dumper);
> +static int open_single_rx_pcap(const char *pcap_filename, pcap_t 
> **pcap);
> +static int open_single_iface(const char *iface, pcap_t **pcap);
> +
>  static struct ether_addr eth_addr = { .addr_bytes = { 0, 0, 0, 0x1,
> 0x2, 0x3 } };
>  static const char *drivername = "Pcap PMD";
>  static struct rte_eth_link pmd_link = {
> @@ -258,6 +269,59 @@ eth_pcap_tx(void *queue,
>  static int
>  eth_dev_start(struct rte_eth_dev *dev)
>  {
> +	unsigned i;
> +	struct pmd_internals *internals = dev->data->dev_private;
> +	struct pcap_tx_queue *tx;
> +	struct pcap_rx_queue *rx;
> +
> +	/* Special iface case. Single pcap is open and shared between tx/rx. 
> */
> +	if (internals->single_iface) {
> +		tx = &internals->tx_queue[0];
> +		rx = &internals->rx_queue[0];
> +
> +		if (!tx->pcap && strcmp(tx->type, ETH_PCAP_IFACE_ARG) == 0) {
> +			if (open_single_iface(tx->name, &tx->pcap) < 0)
> +				return -1;
> +			rx->pcap = tx->pcap;
> +		}
> +		goto status_up;
> +	}
> +
> +	/* If not open already, open tx pcaps/dumpers */
> +	for (i = 0; i < internals->nb_tx_queues; i++) {
> +		tx = &internals->tx_queue[i];
> +
> +		if (!tx->dumper && strcmp(tx->type, ETH_PCAP_TX_PCAP_ARG) == 0) {
> +			if (open_single_tx_pcap(tx->name, &tx->dumper) < 0)
> +				return -1;
> +		}
> +
> +		else if (!tx->pcap && strcmp(tx->type, ETH_PCAP_TX_IFACE_ARG) == 0) 
> {
> +			if (open_single_iface(tx->name, &tx->pcap) < 0)
> +				return -1;
> +		}
> +	}
> +
> +	/* If not open already, open rx pcaps */
> +	for (i = 0; i < internals->nb_rx_queues; i++) {
> +		rx = &internals->rx_queue[i];
> +
> +		if (rx->pcap != NULL)
> +			continue;
> +
> +		if (strcmp(rx->type, ETH_PCAP_RX_PCAP_ARG) == 0) {
> +			if (open_single_rx_pcap(rx->name, &rx->pcap) < 0)
> +				return -1;
> +		}
> +
> +		else if (strcmp(rx->type, ETH_PCAP_RX_IFACE_ARG) == 0) {
> +			if (open_single_iface(rx->name, &rx->pcap) < 0)
> +				return -1;
> +		}
> +	}
> +
> +status_up:
> +
>  	dev->data->dev_link.link_status = 1;
>  	return 0;
>  }
> @@ -271,19 +335,44 @@ static void
>  eth_dev_stop(struct rte_eth_dev *dev)
>  {
>  	unsigned i;
> -	pcap_dumper_t *dumper;
> -	pcap_t *pcap;
>  	struct pmd_internals *internals = dev->data->dev_private;
> +	struct pcap_tx_queue *tx;
> +	struct pcap_rx_queue *rx;
> +
> +	/* Special iface case. Single pcap is open and shared between tx/rx. 
> */
> +	if (internals->single_iface) {
> +		tx = &internals->tx_queue[0];
> +		rx = &internals->rx_queue[0];
> +		pcap_close(tx->pcap);
> +		tx->pcap = NULL;
> +		rx->pcap = NULL;
> +		goto status_down;
> +	}
> 
>  	for (i = 0; i < internals->nb_tx_queues; i++) {
> -		dumper = internals->tx_queue[i].dumper;
> -		if(dumper != NULL)
> -			pcap_dump_close(dumper);
> -		pcap = internals->tx_queue[i].pcap;
> -		if(pcap != NULL)
> -			pcap_close(pcap);
> +		tx = &internals->tx_queue[i];
> +
> +		if (tx->dumper != NULL) {
> +			pcap_dump_close(tx->dumper);
> +			tx->dumper = NULL;
> +		}
> +
> +		if (tx->pcap != NULL) {
> +			pcap_close(tx->pcap);
> +			tx->pcap = NULL;
> +		}
> +	}
> +
> +	for (i = 0; i < internals->nb_rx_queues; i++) {
> +		rx = &internals->rx_queue[i];
> +
> +		if (rx->pcap != NULL) {
> +			pcap_close(rx->pcap);
> +			rx->pcap = NULL;
> +		}
>  	}
> 
> +status_down:
>  	dev->data->dev_link.link_status = 0;
>  }
> 
> @@ -415,55 +504,79 @@ static struct eth_dev_ops ops = {
>   * reference of it for use it later on.
>   */
>  static int
> -open_rx_pcap(const char *key __rte_unused, const char *value, void 
> *extra_args)
> +open_rx_pcap(const char *key, const char *value, void *extra_args)
>  {
>  	unsigned i;
>  	const char *pcap_filename = value;
>  	struct rx_pcaps *pcaps = extra_args;
> -	pcap_t *rx_pcap;
> +	pcap_t *pcap = NULL;
> 
>  	for (i = 0; i < pcaps->num_of_rx; i++) {
> -		if ((rx_pcap = pcap_open_offline(pcap_filename, errbuf)) == NULL) {
> -			RTE_LOG(ERR, PMD, "Couldn't open %s: %s\n", pcap_filename, errbuf);
> +		if (open_single_rx_pcap(pcap_filename, &pcap) < 0)
>  			return -1;
> -		}
> -		pcaps->pcaps[i] = rx_pcap;
> +
> +		pcaps->pcaps[i] = pcap;
> +		pcaps->names[i] = pcap_filename;
> +		pcaps->types[i] = key;
>  	}
> 
>  	return 0;
>  }
> 
> +static int
> +open_single_rx_pcap(const char *pcap_filename, pcap_t **pcap)
> +{
> +	if ((*pcap = pcap_open_offline(pcap_filename, errbuf)) == NULL) {
> +		RTE_LOG(ERR, PMD, "Couldn't open %s: %s\n", pcap_filename, errbuf);
> +		return -1;
> +	}
> +	return 0;
> +}
> +
>  /*
>   * Opens a pcap file for writing and stores a reference to it
>   * for use it later on.
>   */
>  static int
> -open_tx_pcap(const char *key __rte_unused, const char *value, void 
> *extra_args)
> +open_tx_pcap(const char *key, const char *value, void *extra_args)
>  {
>  	unsigned i;
>  	const char *pcap_filename = value;
>  	struct tx_pcaps *dumpers = extra_args;
> -	pcap_t *tx_pcap;
>  	pcap_dumper_t *dumper;
> 
>  	for (i = 0; i < dumpers->num_of_tx; i++) {
> -		/*
> -		 * We need to create a dummy empty pcap_t to use it
> -		 * with pcap_dump_open(). We create big enough an Ethernet
> -		 * pcap holder.
> -		 */
> -		if ((tx_pcap = pcap_open_dead(DLT_EN10MB, 
> RTE_ETH_PCAP_SNAPSHOT_LEN))
> -				== NULL) {
> -			RTE_LOG(ERR, PMD, "Couldn't create dead pcap\n");
> +		if (open_single_tx_pcap(pcap_filename, &dumper) < 0)
>  			return -1;
> -		}
> 
> -		/* The dumper is created using the previous pcap_t reference */
> -		if ((dumper = pcap_dump_open(tx_pcap, pcap_filename)) == NULL) {
> -			RTE_LOG(ERR, PMD, "Couldn't open %s for writing.\n", 
> pcap_filename);
> -			return -1;
> -		}
>  		dumpers->dumpers[i] = dumper;
> +		dumpers->names[i] = pcap_filename;
> +		dumpers->types[i] = key;
> +	}
> +
> +	return 0;
> +}
> +
> +static int
> +open_single_tx_pcap(const char *pcap_filename, pcap_dumper_t **dumper)
> +{
> +	pcap_t *tx_pcap;
> +	/*
> +	 * We need to create a dummy empty pcap_t to use it
> +	 * with pcap_dump_open(). We create big enough an Ethernet
> +	 * pcap holder.
> +	 */
> +
> +	if ((tx_pcap = pcap_open_dead(DLT_EN10MB, RTE_ETH_PCAP_SNAPSHOT_LEN))
> +			== NULL) {
> +		RTE_LOG(ERR, PMD, "Couldn't create dead pcap\n");
> +		return -1;
> +	}
> +
> +	/* The dumper is created using the previous pcap_t reference */
> +	if ((*dumper = pcap_dump_open(tx_pcap, pcap_filename)) == NULL) {
> +		RTE_LOG(ERR, PMD, "Couldn't open %s for writing.\n", pcap_filename);
> +		return -1;
>  	}
> 
>  	return 0;
> @@ -488,13 +601,19 @@ open_iface_live(const char *iface, pcap_t **pcap) 
> {
>   * Opens an interface for reading and writing
>   */
>  static inline int
> -open_rx_tx_iface(const char *key __rte_unused, const char *value,
> void *extra_args)
> +open_rx_tx_iface(const char *key, const char *value, void *extra_args)
>  {
>  	const char *iface = value;
> -	pcap_t **pcap = extra_args;
> +	struct rx_pcaps *pcaps = extra_args;
> +	pcap_t *pcap = NULL;
> 
> -	if(open_iface_live(iface, pcap) < 0)
> +	if (open_single_iface(iface, &pcap) < 0)
>  		return -1;
> +
> +	pcaps->pcaps[0] = pcap;
> +	pcaps->names[0] = iface;
> +	pcaps->types[0] = key;
> +
>  	return 0;
>  }
> 
> @@ -502,7 +621,7 @@ open_rx_tx_iface(const char *key __rte_unused,
> const char *value, void *extra_ar
>   * Opens a NIC for reading packets from it
>   */
>  static inline int
> -open_rx_iface(const char *key __rte_unused, const char *value, void
> *extra_args)
> +open_rx_iface(const char *key, const char *value, void *extra_args)
>  {
>  	unsigned i;
>  	const char *iface = value;
> @@ -510,9 +629,11 @@ open_rx_iface(const char *key __rte_unused, const
> char *value, void *extra_args)
>  	pcap_t *pcap = NULL;
> 
>  	for (i = 0; i < pcaps->num_of_rx; i++) {
> -		if(open_iface_live(iface, &pcap) < 0)
> +		if (open_single_iface(iface, &pcap) < 0)
>  			return -1;
>  		pcaps->pcaps[i] = pcap;
> +		pcaps->names[i] = iface;
> +		pcaps->types[i] = key;
>  	}
> 
>  	return 0;
> @@ -521,8 +642,8 @@ open_rx_iface(const char *key __rte_unused, const
> char *value, void *extra_args)
>  /*
>   * Opens a NIC for writing packets to it
>   */
> -static inline int
> -open_tx_iface(const char *key __rte_unused, const char *value, void
> *extra_args)
> +static int
> +open_tx_iface(const char *key, const char *value, void *extra_args)
>  {
>  	unsigned i;
>  	const char *iface = value;
> @@ -530,14 +651,26 @@ open_tx_iface(const char *key __rte_unused,
> const char *value, void *extra_args)
>  	pcap_t *pcap;
> 
>  	for (i = 0; i < pcaps->num_of_tx; i++) {
> -		if(open_iface_live(iface, &pcap) < 0)
> +		if (open_single_iface(iface, &pcap) < 0)
>  			return -1;
>  		pcaps->pcaps[i] = pcap;
> +		pcaps->names[i] = iface;
> +		pcaps->types[i] = key;
>  	}
> 
>  	return 0;
>  }
> 
> +static int
> +open_single_iface(const char *iface, pcap_t **pcap)
> +{
> +	if (open_iface_live(iface, pcap) < 0) {
> +		RTE_LOG(ERR, PMD, "Couldn't open interface %s\n", iface);
> +		return -1;
> +	}
> +
> +	return 0;
> +}
> 
>  static int
>  rte_pmd_init_internals(const char *name, const unsigned nb_rx_queues,
> @@ -623,9 +756,10 @@ rte_pmd_init_internals(const char *name, const
> unsigned nb_rx_queues,
>  }
> 
>  static int
> -rte_eth_from_pcaps_n_dumpers(const char *name, pcap_t * const 
> rx_queues[],
> +rte_eth_from_pcaps_n_dumpers(const char *name,
> +		struct rx_pcaps *rx_queues,
>  		const unsigned nb_rx_queues,
> -		pcap_dumper_t * const tx_queues[],
> +		struct tx_pcaps *tx_queues,
>  		const unsigned nb_tx_queues,
>  		const unsigned numa_node,
>  		struct rte_kvargs *kvlist)
> @@ -645,25 +779,35 @@ rte_eth_from_pcaps_n_dumpers(const char *name,
> pcap_t * const rx_queues[],
>  		return -1;
> 
>  	for (i = 0; i < nb_rx_queues; i++) {
> -		internals->rx_queue->pcap = rx_queues[i];
> +		internals->rx_queue->pcap = rx_queues->pcaps[i];
> +		internals->rx_queue->name = rx_queues->names[i];
> +		internals->rx_queue->type = rx_queues->types[i];
>  	}
>  	for (i = 0; i < nb_tx_queues; i++) {
> -		internals->tx_queue->dumper = tx_queues[i];
> +		internals->tx_queue->dumper = tx_queues->dumpers[i];
> +		internals->tx_queue->name = tx_queues->names[i];
> +		internals->tx_queue->type = tx_queues->types[i];
>  	}
> 
> +	/* using multiple pcaps/interfaces */
> +	internals->single_iface = 0;
> +
>  	eth_dev->rx_pkt_burst = eth_pcap_rx;
>  	eth_dev->tx_pkt_burst = eth_pcap_tx_dumper;
> 
>  	return 0;
>  }
> 
> +	struct rx_pcaps pcaps;
>  static int
> -rte_eth_from_pcaps(const char *name, pcap_t * const rx_queues[],
> +rte_eth_from_pcaps(const char *name,
> +		struct rx_pcaps *rx_queues,
>  		const unsigned nb_rx_queues,
> -		pcap_t * const tx_queues[],
> +		struct tx_pcaps *tx_queues,
>  		const unsigned nb_tx_queues,
>  		const unsigned numa_node,
> -		struct rte_kvargs *kvlist)
> +		struct rte_kvargs *kvlist,
> +		int single_iface)
>  {
>  	struct pmd_internals *internals = NULL;
>  	struct rte_eth_dev *eth_dev = NULL;
> @@ -680,12 +824,19 @@ rte_eth_from_pcaps(const char *name, pcap_t *
> const rx_queues[],
>  		return -1;
> 
>  	for (i = 0; i < nb_rx_queues; i++) {
> -		internals->rx_queue->pcap = rx_queues[i];
> +		internals->rx_queue->pcap = rx_queues->pcaps[i];
> +		internals->rx_queue->name = rx_queues->names[i];
> +		internals->rx_queue->type = rx_queues->types[i];
>  	}
>  	for (i = 0; i < nb_tx_queues; i++) {
> -		internals->tx_queue->pcap = tx_queues[i];
> +		internals->tx_queue->pcap = tx_queues->pcaps[i];
> +		internals->tx_queue->name = tx_queues->names[i];
> +		internals->tx_queue->type = tx_queues->types[i];
>  	}
> 
> +	/* store wether we are using a single interface for rx/tx or not */
> +	internals->single_iface = single_iface;
> +
>  	eth_dev->rx_pkt_burst = eth_pcap_rx;
>  	eth_dev->tx_pkt_burst = eth_pcap_tx;
> 
> @@ -721,12 +872,14 @@ rte_pmd_pcap_devinit(const char *name, const char 
> *params)
>  	if (rte_kvargs_count(kvlist, ETH_PCAP_IFACE_ARG) == 1) {
> 
>  		ret = rte_kvargs_process(kvlist, ETH_PCAP_IFACE_ARG,
> -				&open_rx_tx_iface, &pcaps.pcaps[0]);
> +				&open_rx_tx_iface, &pcaps);
>  		if (ret < 0)
>  			return -1;
> -
> -		return rte_eth_from_pcaps(name, pcaps.pcaps, 1, pcaps.pcaps, 1,
> -				numa_node, kvlist);
> +		dumpers.pcaps[0] = pcaps.pcaps[0];
> +		dumpers.names[0] = pcaps.names[0];
> +		dumpers.types[0] = pcaps.types[0];
> +		return rte_eth_from_pcaps(name, &pcaps, 1, &dumpers, 1,
> +				numa_node, kvlist, 1);
>  	}
> 
>  	/*
> @@ -766,11 +919,11 @@ rte_pmd_pcap_devinit(const char *name, const char 
> *params)
>  		return -1;
> 
>  	if (using_dumpers)
> -		return rte_eth_from_pcaps_n_dumpers(name, pcaps.pcaps, 
> pcaps.num_of_rx,
> -				dumpers.dumpers, dumpers.num_of_tx, numa_node, kvlist);
> +		return rte_eth_from_pcaps_n_dumpers(name, &pcaps, pcaps.num_of_rx,
> +				&dumpers, dumpers.num_of_tx, numa_node, kvlist);
> 
> -	return rte_eth_from_pcaps(name, pcaps.pcaps, pcaps.num_of_rx, 
> dumpers.pcaps,
> -			dumpers.num_of_tx, numa_node, kvlist);
> +	return rte_eth_from_pcaps(name, &pcaps, pcaps.num_of_rx, &dumpers,
> +			dumpers.num_of_tx, numa_node, kvlist, 0);
> 
>  }