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ip_frag: refactor IPv4 fragmentation into a proper library
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Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
[Thomas: add in doxygen]
Acked-by: Thomas Monjalon <thomas.monjalon@6wind.com>
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@anatolyburakov
anatolyburakov authored and Thomas Monjalon committed Jun 16, 2014
1 parent 601e279 commit 4c38e55
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Showing 7 changed files with 272 additions and 183 deletions.
1 change: 1 addition & 0 deletions doc/doxy-api-index.md
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Expand Up @@ -78,6 +78,7 @@ There are many libraries, so their headers may be grouped by topics:
[SCTP] (@ref rte_sctp.h),
[TCP] (@ref rte_tcp.h),
[UDP] (@ref rte_udp.h),
[frag/reass] (@ref rte_ip_frag.h),
[LPM route] (@ref rte_lpm.h),
[ACL] (@ref rte_acl.h)

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1 change: 1 addition & 0 deletions doc/doxy-api.conf
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Expand Up @@ -35,6 +35,7 @@ INPUT = doc/doxy-api-index.md \
lib/librte_distributor \
lib/librte_ether \
lib/librte_hash \
lib/librte_ip_frag \
lib/librte_kni \
lib/librte_kvargs \
lib/librte_lpm \
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11 changes: 11 additions & 0 deletions examples/ipv4_frag/main.c
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Expand Up @@ -74,6 +74,17 @@
#include "rte_ip_frag.h"
#include "main.h"

/*
* Default byte size for the IPv4 Maximum Transfer Unit (MTU).
* This value includes the size of IPv4 header.
*/
#define IPV4_MTU_DEFAULT ETHER_MTU

/*
* Default payload in bytes for the IPv4 packet.
*/
#define IPV4_DEFAULT_PAYLOAD (IPV4_MTU_DEFAULT - sizeof(struct ipv4_hdr))

#define RTE_LOGTYPE_L3FWD RTE_LOGTYPE_USER1

#define MBUF_SIZE (2048 + sizeof(struct rte_mbuf) + RTE_PKTMBUF_HEADROOM)
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9 changes: 9 additions & 0 deletions lib/librte_ip_frag/Makefile
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Expand Up @@ -31,6 +31,15 @@

include $(RTE_SDK)/mk/rte.vars.mk

# library name
LIB = librte_ip_frag.a

CFLAGS += -O3
CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR)

#source files
SRCS-$(CONFIG_RTE_LIBRTE_IP_FRAG) += rte_ipv4_fragmentation.c

# install this header file
SYMLINK-$(CONFIG_RTE_LIBRTE_IP_FRAG)-include += rte_ip_frag.h
SYMLINK-$(CONFIG_RTE_LIBRTE_IP_FRAG)-include += ipv4_frag_tbl.h
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190 changes: 7 additions & 183 deletions lib/librte_ip_frag/rte_ip_frag.h
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Expand Up @@ -31,9 +31,8 @@
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#ifndef __INCLUDE_RTE_IPV4_FRAG_H__
#define __INCLUDE_RTE_IPV4_FRAG_H__
#include <rte_ip.h>
#ifndef _RTE_IP_FRAG_H__
#define _RTE_IP_FRAG_H__

/**
* @file
Expand All @@ -43,67 +42,6 @@
*
*/

/*
* Default byte size for the IPv4 Maximum Transfer Unit (MTU).
* This value includes the size of IPv4 header.
*/
#define IPV4_MTU_DEFAULT ETHER_MTU

/*
* Default payload in bytes for the IPv4 packet.
*/
#define IPV4_DEFAULT_PAYLOAD (IPV4_MTU_DEFAULT - sizeof(struct ipv4_hdr))

/*
* MAX number of fragments per packet allowed.
*/
#define IPV4_MAX_FRAGS_PER_PACKET 0x80


/* Debug on/off */
#ifdef RTE_IPV4_FRAG_DEBUG

#define RTE_IPV4_FRAG_ASSERT(exp) \
if (!(exp)) { \
rte_panic("function %s, line%d\tassert \"" #exp "\" failed\n", \
__func__, __LINE__); \
}

#else /*RTE_IPV4_FRAG_DEBUG*/

#define RTE_IPV4_FRAG_ASSERT(exp) do { } while(0)

#endif /*RTE_IPV4_FRAG_DEBUG*/

/* Fragment Offset */
#define IPV4_HDR_DF_SHIFT 14
#define IPV4_HDR_MF_SHIFT 13
#define IPV4_HDR_FO_SHIFT 3

#define IPV4_HDR_DF_MASK (1 << IPV4_HDR_DF_SHIFT)
#define IPV4_HDR_MF_MASK (1 << IPV4_HDR_MF_SHIFT)

#define IPV4_HDR_FO_MASK ((1 << IPV4_HDR_FO_SHIFT) - 1)

static inline void __fill_ipv4hdr_frag(struct ipv4_hdr *dst,
const struct ipv4_hdr *src, uint16_t len, uint16_t fofs,
uint16_t dofs, uint32_t mf)
{
rte_memcpy(dst, src, sizeof(*dst));
fofs = (uint16_t)(fofs + (dofs >> IPV4_HDR_FO_SHIFT));
fofs = (uint16_t)(fofs | mf << IPV4_HDR_MF_SHIFT);
dst->fragment_offset = rte_cpu_to_be_16(fofs);
dst->total_length = rte_cpu_to_be_16(len);
dst->hdr_checksum = 0;
}

static inline void __free_fragments(struct rte_mbuf *mb[], uint32_t num)
{
uint32_t i;
for (i = 0; i != num; i++)
rte_pktmbuf_free(mb[i]);
}

/**
* IPv4 fragmentation.
*
Expand All @@ -113,6 +51,8 @@ static inline void __free_fragments(struct rte_mbuf *mb[], uint32_t num)
* The input packet.
* @param pkts_out
* Array storing the output fragments.
* @param nb_pkts_out
* Number of fragments.
* @param mtu_size
* Size in bytes of the Maximum Transfer Unit (MTU) for the outgoing IPv4
* datagrams. This value includes the size of the IPv4 header.
Expand All @@ -123,129 +63,13 @@ static inline void __free_fragments(struct rte_mbuf *mb[], uint32_t num)
* @return
* Upon successful completion - number of output fragments placed
* in the pkts_out array.
* Otherwise - (-1) * <errno>.
* Otherwise - (-1) * errno.
*/
static inline int32_t rte_ipv4_fragmentation(struct rte_mbuf *pkt_in,
int32_t rte_ipv4_fragmentation(struct rte_mbuf *pkt_in,
struct rte_mbuf **pkts_out,
uint16_t nb_pkts_out,
uint16_t mtu_size,
struct rte_mempool *pool_direct,
struct rte_mempool *pool_indirect)
{
struct rte_mbuf *in_seg = NULL;
struct ipv4_hdr *in_hdr;
uint32_t out_pkt_pos, in_seg_data_pos;
uint32_t more_in_segs;
uint16_t fragment_offset, flag_offset, frag_size;

frag_size = (uint16_t)(mtu_size - sizeof(struct ipv4_hdr));

/* Fragment size should be a multiply of 8. */
RTE_IPV4_FRAG_ASSERT((frag_size & IPV4_HDR_FO_MASK) == 0);

/* Fragment size should be a multiply of 8. */
RTE_IPV4_FRAG_ASSERT(IPV4_MAX_FRAGS_PER_PACKET * frag_size >=
(uint16_t)(pkt_in->pkt.pkt_len - sizeof (struct ipv4_hdr)));

in_hdr = (struct ipv4_hdr*) pkt_in->pkt.data;
flag_offset = rte_cpu_to_be_16(in_hdr->fragment_offset);

/* If Don't Fragment flag is set */
if (unlikely ((flag_offset & IPV4_HDR_DF_MASK) != 0))
return (-ENOTSUP);

/* Check that pkts_out is big enough to hold all fragments */
if (unlikely (frag_size * nb_pkts_out <
(uint16_t)(pkt_in->pkt.pkt_len - sizeof (struct ipv4_hdr))))
return (-EINVAL);

in_seg = pkt_in;
in_seg_data_pos = sizeof(struct ipv4_hdr);
out_pkt_pos = 0;
fragment_offset = 0;

more_in_segs = 1;
while (likely(more_in_segs)) {
struct rte_mbuf *out_pkt = NULL, *out_seg_prev = NULL;
uint32_t more_out_segs;
struct ipv4_hdr *out_hdr;

/* Allocate direct buffer */
out_pkt = rte_pktmbuf_alloc(pool_direct);
if (unlikely(out_pkt == NULL)) {
__free_fragments(pkts_out, out_pkt_pos);
return (-ENOMEM);
}

/* Reserve space for the IP header that will be built later */
out_pkt->pkt.data_len = sizeof(struct ipv4_hdr);
out_pkt->pkt.pkt_len = sizeof(struct ipv4_hdr);

out_seg_prev = out_pkt;
more_out_segs = 1;
while (likely(more_out_segs && more_in_segs)) {
struct rte_mbuf *out_seg = NULL;
uint32_t len;

/* Allocate indirect buffer */
out_seg = rte_pktmbuf_alloc(pool_indirect);
if (unlikely(out_seg == NULL)) {
rte_pktmbuf_free(out_pkt);
__free_fragments(pkts_out, out_pkt_pos);
return (-ENOMEM);
}
out_seg_prev->pkt.next = out_seg;
out_seg_prev = out_seg;

/* Prepare indirect buffer */
rte_pktmbuf_attach(out_seg, in_seg);
len = mtu_size - out_pkt->pkt.pkt_len;
if (len > (in_seg->pkt.data_len - in_seg_data_pos)) {
len = in_seg->pkt.data_len - in_seg_data_pos;
}
out_seg->pkt.data = (char*) in_seg->pkt.data + (uint16_t)in_seg_data_pos;
out_seg->pkt.data_len = (uint16_t)len;
out_pkt->pkt.pkt_len = (uint16_t)(len +
out_pkt->pkt.pkt_len);
out_pkt->pkt.nb_segs += 1;
in_seg_data_pos += len;

/* Current output packet (i.e. fragment) done ? */
if (unlikely(out_pkt->pkt.pkt_len >= mtu_size)) {
more_out_segs = 0;
}

/* Current input segment done ? */
if (unlikely(in_seg_data_pos == in_seg->pkt.data_len)) {
in_seg = in_seg->pkt.next;
in_seg_data_pos = 0;

if (unlikely(in_seg == NULL)) {
more_in_segs = 0;
}
}
}

/* Build the IP header */

out_hdr = (struct ipv4_hdr*) out_pkt->pkt.data;

__fill_ipv4hdr_frag(out_hdr, in_hdr,
(uint16_t)out_pkt->pkt.pkt_len,
flag_offset, fragment_offset, more_in_segs);

fragment_offset = (uint16_t)(fragment_offset +
out_pkt->pkt.pkt_len - sizeof(struct ipv4_hdr));

out_pkt->ol_flags |= PKT_TX_IP_CKSUM;
out_pkt->pkt.vlan_macip.f.l3_len = sizeof(struct ipv4_hdr);

/* Write the fragment to the output list */
pkts_out[out_pkt_pos] = out_pkt;
out_pkt_pos ++;
}

return (out_pkt_pos);
}
struct rte_mempool *pool_indirect);

#endif

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