trafgen: dev_io: Change read/write to specify struct packet *

Refactor dev_io_ops read & write to specify struct packet *,
it may simplify a bit a caller logic. And it allow to keep
required members within one struct packet object.

Signed-off-by: Vadim Kochan <vadim4j@gmail.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

5 files changed, 49 insertions, 44 deletions

diff --git a/trafgen.c b/trafgen.c
index 207b680..97ac046 100644
--- a/trafgen.c
+++ b/trafgen.c
@@ -684,7 +684,7 @@ static void xmit_slowpath_or_die(struct ctx *ctx, unsigned int cpu, unsigned lon
 	while (likely(sigint == 0 && num > 0 && plen > 0)) {
 		packet_apply_dyn_elements(i);
 retry:
-		ret = dev_io_write(ctx->dev_out, packets[i].payload, packets[i].len);
+		ret = dev_io_write(ctx->dev_out, &packets[i]);
 		if (unlikely(ret < 0)) {
 			if (errno == ENOBUFS) {
 				sched_yield();
@@ -937,27 +937,10 @@ static void xmit_packet_precheck(struct ctx *ctx, unsigned int cpu)
 
 static void pcap_load_packets(struct dev_io *dev)
 {
-	struct timespec tstamp;
-	size_t buf_len;
-	uint8_t *buf;
-	int pkt_len;
+	struct packet *pkt;
 
-	buf_len = round_up(1024 * 1024, RUNTIME_PAGE_SIZE);
-	buf = xmalloc_aligned(buf_len, CO_CACHE_LINE_SIZE);
-
-	while ((pkt_len = dev_io_read(dev, buf, buf_len, &tstamp)) > 0) {
-		struct packet *pkt;
-
-		realloc_packet();
-
-		pkt = current_packet();
-		pkt->len = pkt_len;
-		pkt->payload = xzmalloc(pkt_len);
-		memcpy(pkt->payload, buf, pkt_len);
-		memcpy(&pkt->tstamp, &tstamp, sizeof(tstamp));
-	}
-
-	free(buf);
+	while ((pkt = dev_io_read(dev)) != 0)
+		/* nothing to do */;
 }
 
 static void main_loop(struct ctx *ctx, char *confname, bool slow,
diff --git a/trafgen_conf.h b/trafgen_conf.h
index 2af830d..7e922fe 100644
--- a/trafgen_conf.h
+++ b/trafgen_conf.h
@@ -80,6 +80,6 @@ extern void set_fill(uint8_t val, size_t len);
 extern struct packet *current_packet(void);
 extern uint32_t current_packet_id(void);
 extern struct packet *packet_get(uint32_t id);
-extern void realloc_packet(void);
+extern struct packet *realloc_packet(void);
 
 #endif /* TRAFGEN_CONF */
diff --git a/trafgen_dev.c b/trafgen_dev.c
index d7f1cd5..d613cce 100644
--- a/trafgen_dev.c
+++ b/trafgen_dev.c
@@ -19,6 +19,7 @@
 #include "mac80211.h"
 #include "linktype.h"
 #include "trafgen_dev.h"
+#include "trafgen_conf.h"
 
 static int dev_pcap_open(struct dev_io *dev, const char *name, enum dev_io_mode_t mode)
 {
@@ -36,6 +37,8 @@ static int dev_pcap_open(struct dev_io *dev, const char *name, enum dev_io_mode_
 		}
 
 		dev->pcap_mode = PCAP_MODE_RD;
+		dev->buf_len = round_up(1024 * 1024, RUNTIME_PAGE_SIZE);
+		dev->buf = xmalloc_aligned(dev->buf_len, CO_CACHE_LINE_SIZE);
 	} else if (mode & DEV_IO_OUT) {
 		if (!strncmp("-", name, strlen("-"))) {
 			dev->fd = dup_or_die(fileno(stdout));
@@ -69,26 +72,35 @@ static int dev_pcap_open(struct dev_io *dev, const char *name, enum dev_io_mode_
 	return 0;
 }
 
-static int dev_pcap_read(struct dev_io *dev, uint8_t *buf, size_t len,
-			 struct timespec *tstamp)
+static struct packet *dev_pcap_read(struct dev_io *dev)
 {
+	size_t len = dev->buf_len;
+	uint8_t *buf = dev->buf;
 	pcap_pkthdr_t phdr;
+	struct packet *pkt;
 	size_t pkt_len;
 
 	if (dev->pcap_ops->read_pcap(dev->fd, &phdr, dev->pcap_magic, buf, len) <= 0)
-		return -1;
+		return NULL;
 
 	pkt_len = pcap_get_length(&phdr, dev->pcap_magic);
 	if (!pkt_len)
-		return -1;
+		return NULL;
 
-	pcap_get_tstamp(&phdr, dev->pcap_magic, tstamp);
+	pkt = realloc_packet();
 
-	return pkt_len;
+	pkt->len = pkt_len;
+	pkt->payload = xzmalloc(pkt_len);
+	memcpy(pkt->payload, buf, pkt_len);
+	pcap_get_tstamp(&phdr, dev->pcap_magic, &pkt->tstamp);
+
+	return pkt;
 }
 
-static int dev_pcap_write(struct dev_io *dev, const uint8_t *buf, size_t len)
+static int dev_pcap_write(struct dev_io *dev, const struct packet *pkt)
 {
+	uint8_t *buf = pkt->payload;
+	size_t len = pkt->len;
 	struct timeval time;
 	pcap_pkthdr_t phdr;
 	int ret;
@@ -130,8 +142,13 @@ static int dev_pcap_write(struct dev_io *dev, const uint8_t *buf, size_t len)
 
 static void dev_pcap_close(struct dev_io *dev)
 {
-	if (dev->pcap_mode == PCAP_MODE_WR)
+	if (dev->pcap_mode == PCAP_MODE_WR) {
 		dev->pcap_ops->fsync_pcap(dev->fd);
+	} else if (dev->pcap_mode == PCAP_MODE_RD) {
+		free(dev->buf);
+		dev->buf_len = 0;
+		dev->buf = NULL;
+	}
 
 	if (dev->pcap_ops->prepare_close_pcap)
 		dev->pcap_ops->prepare_close_pcap(dev->fd, dev->pcap_mode);
@@ -155,13 +172,15 @@ static int dev_net_open(struct dev_io *dev, const char *name, enum dev_io_mode_t
 	return 0;
 }
 
-static int dev_net_write(struct dev_io *dev, const uint8_t *buf, size_t len)
+static int dev_net_write(struct dev_io *dev, const struct packet *pkt)
 {
 	struct sockaddr_ll saddr = {
 		.sll_family = PF_PACKET,
 		.sll_halen = ETH_ALEN,
 		.sll_ifindex = dev->ifindex,
 	};
+	uint8_t *buf = pkt->payload;
+	size_t len = pkt->len;
 
 	return sendto(dev->fd, buf, len, 0, (struct sockaddr *) &saddr, sizeof(saddr));
 }
@@ -221,27 +240,26 @@ struct dev_io *dev_io_open(const char *name, enum dev_io_mode_t mode)
 	return dev;
 };
 
-int dev_io_write(struct dev_io *dev, const uint8_t *buf, size_t len)
+int dev_io_write(struct dev_io *dev, const struct packet *pkt)
 {
 	bug_on(!dev);
 	bug_on(!dev->ops);
 
 	if (dev->ops->write)
-		return dev->ops->write(dev, buf, len);
+		return dev->ops->write(dev, pkt);
 
 	return 0;
 }
 
-int dev_io_read(struct dev_io *dev, uint8_t *buf, size_t len,
-		struct timespec *tstamp)
+struct packet *dev_io_read(struct dev_io *dev)
 {
 	bug_on(!dev);
 	bug_on(!dev->ops);
 
 	if (dev->ops->read)
-		return dev->ops->read(dev, buf, len, tstamp);
+		return dev->ops->read(dev);
 
-	return 0;
+	return NULL;
 }
 
 const char *dev_io_name_get(struct dev_io *dev)
diff --git a/trafgen_dev.h b/trafgen_dev.h
index 686a577..6708eb8 100644
--- a/trafgen_dev.h
+++ b/trafgen_dev.h
@@ -12,6 +12,7 @@ enum dev_io_mode_t {
 };
 
 struct dev_io_ops;
+struct packet;
 
 struct dev_io {
 	int fd;
@@ -23,6 +24,8 @@ struct dev_io {
 	uint32_t pcap_magic;
 	bool is_initialized;
 	enum pcap_mode pcap_mode;
+	size_t buf_len;
+	uint8_t *buf;
 
 	const struct pcap_file_ops *pcap_ops;
 	const struct dev_io_ops *ops;
@@ -30,16 +33,15 @@ struct dev_io {
 
 struct dev_io_ops {
 	int(*open) (struct dev_io *dev, const char *name, enum dev_io_mode_t mode);
-	int(*write) (struct dev_io *dev, const uint8_t *buf, size_t len);
-	int(*read) (struct dev_io *dev, uint8_t *buf, size_t len, struct timespec *tstamp);
+	int(*write) (struct dev_io *dev, const struct packet *pkt);
+	struct packet *(*read) (struct dev_io *dev);
 	int(*set_link_type) (struct dev_io *dev, int link_type);
 	void(*close) (struct dev_io *dev);
 };
 
 extern struct dev_io *dev_io_open(const char *name, enum dev_io_mode_t mode);
-extern int dev_io_write(struct dev_io *dev, const uint8_t *buf, size_t len);
-extern int dev_io_read(struct dev_io *dev, uint8_t *buf, size_t len,
-		       struct timespec *tstamp);
+extern int dev_io_write(struct dev_io *dev, const struct packet *pkt);
+extern struct packet *dev_io_read(struct dev_io *dev);
 extern int dev_io_ifindex_get(struct dev_io *dev);
 extern int dev_io_fd_get(struct dev_io *dev);
 extern const char *dev_io_name_get(struct dev_io *dev);
diff --git a/trafgen_parser.y b/trafgen_parser.y
index 656c4f6..74015b5 100644
--- a/trafgen_parser.y
+++ b/trafgen_parser.y
@@ -167,10 +167,10 @@ static inline void __setup_new_csum16(struct csum16 *s, off_t from, off_t to,
 	s->which = which;
 }
 
-void realloc_packet(void)
+struct packet *realloc_packet(void)
 {
 	if (test_ignore())
-		return;
+		return NULL;
 
 	plen++;
 	packets = xrealloc(packets, plen * sizeof(*packets));
@@ -184,6 +184,8 @@ void realloc_packet(void)
 	__init_new_randomizer_slot(&packet_dyn[packetd_last]);
 	__init_new_csum_slot(&packet_dyn[packetd_last]);
 	__init_new_fields_slot(&packet_dyn[packetd_last]);
+
+	return &packets[packet_last];
 }
 
 struct packet *current_packet(void)