How to generate incremental data value in DPDK - c

Code image
Hello DPDK Users,
I was trying to generate the incremental data value of UDP packets via DPDK.
But when I am transmitting it, I verified the same frames in Wireshark.
The data part of packets is changing illogically.
No sequence can be seen in data.
It is optimized the data value which I was wrote. The last value i tried to write was there in all the bytes of payload, not as expected in incremental order.
Can anyone help me, why is this occurring and what could be the easiest way to generate incremental DPDK packets?
The Code is given in the image file above.

#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>
#include <unistd.h>
#include <inttypes.h>
#include<assert.h>
uint64_t temp1;
uint64_t temp2;
int temp3;
int test_type;
double sec;
time_t start_t,end_t;
double diff_t;
#include<time.h>
#include<signal.h>
#include<linux/kernel.h>
#include <rte_memory.h>
#include <rte_launch.h>
#include <rte_eal.h>
#include <rte_per_lcore.h>
#include <rte_lcore.h>
#include <rte_ethdev.h>
#include <rte_udp.h>
#include <rte_tcp.h>
#include <rte_ip.h>
#include <rte_arp.h>
#include <rte_icmp.h>
#include <rte_cycles.h>
#include <rte_lcore.h>
#include <rte_mbuf.h>
#define RX_RING_SIZE 2028
#define TX_RING_SIZE 2048
#define NUM_MBUFS 8191
#define MBUF_CACHE_SIZE 250
#define BURST_SIZE 32
#define UDP_SRC_PORT 6666
#define UDP_DST_PORT 6666
#define TCP_SRC_PORT 6666
#define TCP_DST_PORT 6666
#define IP_DEFTTL 64
#define IP_VERSION 0x40
#define IP_HDRLEN 0x05
#define IP_VHL_DEF (IP_VERSION | IP_HDRLEN)
#define TX_PACKET_LENGTH 64
#define ETHER_MAX_LEN 1518
#if RTE_BYTE_ORDER == RTE_BIG_ENDIAN
#define RTE_BE_TO_CPU_16(be_16_v) (be_16_v)
#define RTE_CPU_TO_BE_16(cpu_16_v) (cpu_16_v)
#else
#define RTE_BE_TO_CPU_16(be_16_v) \
(uint16_t) ((((be_16_v) & 0xFF) << 8) | ((be_16_v) >> 8))
#define RTE_CPU_TO_BE_16(cpu_16_v) \
(uint16_t) ((((cpu_16_v) & 0xFF) << 8) | ((cpu_16_v) >> 8))
#endif
#define rte_ctrlmbuf_data(m) ((char *)((m)->buf_addr)+(m)->data_off)
// convert a quad-dot IP string to uint32_t IP address
uint32_t string_to_ip(char *s) {
unsigned char a[4];
int rc = sscanf(s, "%d.%d.%d.%d",a+0,a+1,a+2,a+3);
if(rc != 4){
fprintf(stderr, "bad source IP address format. Use like: -s 198.19.111.179\n");
exit(1);
}
return
(uint32_t)(a[0]) << 24 |
(uint32_t)(a[1]) << 16 |
(uint32_t)(a[2]) << 8 |
(uint32_t)(a[3]);
}
// convert six colon separated hex bytes string to uint64_t Ethernet MAC address
uint64_t string_to_mac(char *s) {
unsigned char a[6];
int rc = sscanf(s, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx",
a + 0, a + 1, a + 2, a + 3, a + 4, a + 5);
if(rc !=6 ){
fprintf(stderr, "bad MAC address format. Use like: -m 0a:38:ca:f6:f3:20\n");
exit(1);
}
return
(uint64_t)(a[0]) << 40 |
(uint64_t)(a[1]) << 32 |
(uint64_t)(a[2]) << 24 |
(uint64_t)(a[3]) << 16 |
(uint64_t)(a[4]) << 8 |
(uint64_t)(a[5]);
}
uint64_t DST_MAC;
uint32_t IP_SRC_ADDR,IP_DST_ADDR;
static const struct rte_eth_conf port_conf_default = {
.rxmode = { .max_rx_pkt_len = RTE_ETHER_MAX_LEN }
};
static struct rte_ipv4_hdr pkt_ip_hdr;
static struct rte_udp_hdr pkt_udp_hdr;
struct rte_ether_addr my_addr;
struct rte_mempool *mbuf_pool;
struct rte_data_hdr pkt_data_hdr;
static void setup_pkt_udp_ip_headers(struct rte_ipv4_hdr *ip_hdr,
struct rte_udp_hdr *pudp_hdr,
uint16_t pkt_data_len)
{
uint16_t *ptr16;
uint32_t ip_cksum;
uint16_t pkt_len;
int sizeof_=sizeof(struct rte_udp_hdr);
int sizeof__=sizeof(struct rte_ipv4_hdr);
//initialize udp headers
pkt_len = (uint16_t) (pkt_data_len + sizeof_);
pudp_hdr->src_port = rte_cpu_to_be_16(UDP_SRC_PORT);
pudp_hdr->dst_port = rte_cpu_to_be_16(UDP_DST_PORT);
pudp_hdr->dgram_len = RTE_CPU_TO_BE_16(pkt_len);
pudp_hdr->dgram_cksum = 32; // No udp checksum.
//Initialize IP header.
pkt_len = (uint16_t) (pkt_len + sizeof__);
ip_hdr->version_ihl = IP_VHL_DEF;
ip_hdr->type_of_service = 0;
ip_hdr->fragment_offset = 0;
ip_hdr->time_to_live = IP_DEFTTL;
ip_hdr->next_proto_id = IPPROTO_UDP;
ip_hdr->packet_id = 0;
ip_hdr->total_length = RTE_CPU_TO_BE_16(pkt_len);
ip_hdr->src_addr = rte_cpu_to_be_32(IP_SRC_ADDR);
ip_hdr->dst_addr = rte_cpu_to_be_32(IP_DST_ADDR);
//Compute IP header checksum.
ptr16 = (unaligned_uint16_t*) ip_hdr;
ip_cksum = 0;
ip_cksum += ptr16[0]; ip_cksum += ptr16[1];
ip_cksum += ptr16[2]; ip_cksum += ptr16[3];
ip_cksum += ptr16[4];
ip_cksum += ptr16[6]; ip_cksum += ptr16[7];
ip_cksum += ptr16[8]; ip_cksum += ptr16[9];
//Reduce 32 bit checksum to 16 bits and complement it.
ip_cksum = ((ip_cksum & 0xFFFF0000) >> 16) +
(ip_cksum & 0x0000FFFF);
if (ip_cksum > 65535)
ip_cksum -= 65535;
ip_cksum = (~ip_cksum) & 0x0000FFFF;
if (ip_cksum == 0)
ip_cksum = 0xFFFF;
ip_hdr->hdr_checksum = (uint16_t) ip_cksum;
}
union {
uint64_t as_int;
struct rte_ether_addr as_addr;
} dst_eth_addr;
static void packetsend_withSequence()
{
int counter=1;
int pkt_drop_counter=0;
struct rte_ether_hdr eth_hdr;
struct rte_mbuf *pkt=NULL;
struct rte_mbuf *pkts_burst[1];
struct rte_mbuf *m;
char *data;
char temppacketdata[100];
while(1){
pkt = rte_pktmbuf_alloc(mbuf_pool);
if(pkt == NULL) {printf("trouble at rte_mbuf_raw_alloc\n");}
data = rte_pktmbuf_append(pkt, TX_PACKET_LENGTH);
if(data == NULL ) {printf("trouble at data alloc\n");}
// set up addresses
printf("\n rte_pktmbuf_pkt_len is %d", rte_pktmbuf_pkt_len(pkt));
dst_eth_addr.as_int=rte_cpu_to_be_64(DST_MAC);
rte_ether_addr_copy(&dst_eth_addr,&eth_hdr.d_addr);
rte_ether_addr_copy(&my_addr, &eth_hdr.s_addr);
eth_hdr.ether_type = rte_cpu_to_be_16(RTE_ETHER_TYPE_IPV4);
memset(temppacketdata,0x0,sizeof(temppacketdata));
memcpy(temppacketdata, &eth_hdr,(size_t)sizeof(eth_hdr)); //copy eth header
memcpy(temppacketdata+(size_t)sizeof(eth_hdr), &pkt_ip_hdr,(size_t)sizeof(pkt_ip_hdr)); //copy IP header
memcpy(temppacketdata+(size_t)sizeof(eth_hdr)+(size_t)sizeof(pkt_ip_hdr), &pkt_udp_hdr,(size_t)sizeof(pkt_udp_hdr)); //copy UDP header
memcpy(temppacketdata+(size_t)sizeof(eth_hdr)+(size_t)sizeof(pkt_ip_hdr)+(size_t)sizeof(pkt_udp_hdr), &counter,(size_t)sizeof(counter)); //copy int data
memcpy(data,temppacketdata,rte_pktmbuf_pkt_len(pkt));
pkts_burst[0] = pkt;
const uint16_t nb_tx = rte_eth_tx_burst(0, 0, pkts_burst,1);
if (unlikely(nb_tx < 1))
{
pkt_drop_counter++;
rte_pktmbuf_free(pkt); // This frees chained segs
}
else{
counter++;
printf("%d",nb_tx);
}
if(counter > 1000)
break;
}
printf(" pkt_drop_counter = %d counter =%d",pkt_drop_counter,counter);
}
// Initialize Port
static inline int
port_init(uint16_t port, struct rte_mempool *mbuf_pool)
{
struct rte_eth_conf port_conf = port_conf_default;
const uint16_t rx_rings = 1, tx_rings = 1;
uint16_t nb_rxd = RX_RING_SIZE;
uint16_t nb_txd = TX_RING_SIZE;
int retval;
uint16_t q;
struct rte_eth_dev_info dev_info;
struct rte_eth_txconf txconf;
if (!rte_eth_dev_is_valid_port(port))
return -1;
rte_eth_dev_info_get(port, &dev_info);
if (dev_info.tx_offload_capa & DEV_TX_OFFLOAD_MBUF_FAST_FREE)
port_conf.txmode.offloads |=
DEV_TX_OFFLOAD_MBUF_FAST_FREE;
/* Configure the Ethernet device. */
retval = rte_eth_dev_configure(port, rx_rings, tx_rings, &port_conf);
if (retval != 0)
return retval;
retval = rte_eth_dev_adjust_nb_rx_tx_desc(port, &nb_rxd, &nb_txd);
if (retval != 0)
return retval;
txconf = dev_info.default_txconf;
txconf.offloads = port_conf.txmode.offloads;
//Allocate and set up 1 TX queue
for (q = 0; q < tx_rings; q++) {
retval = rte_eth_tx_queue_setup(port, q, nb_txd,
rte_eth_dev_socket_id(port), &txconf);
if (retval < 0)
return retval;
}
/* Allocate and set up 1 RX queue per Ethernet port. */
for (q = 0; q < rx_rings; q++) {
retval = rte_eth_rx_queue_setup(port, q, nb_rxd,
rte_eth_dev_socket_id(port), NULL, mbuf_pool);
if (retval < 0)
return retval;
}
/* Start the Ethernet port. */
retval = rte_eth_dev_start(port);
if (retval < 0)
return retval;
/* get the port MAC address. */
rte_eth_macaddr_get(port, &my_addr);
printf("Port %u MAC: %02" PRIx8 " %02" PRIx8 " %02" PRIx8
" %02" PRIx8 " %02" PRIx8 " %02" PRIx8 "\n",
port,
my_addr.addr_bytes[0], my_addr.addr_bytes[1],
my_addr.addr_bytes[2], my_addr.addr_bytes[3],
my_addr.addr_bytes[4], my_addr.addr_bytes[5]);
return 0;
}
int main(int argc, char **argv)
{
int ret,c;
uint16_t pkt_data_len;
int mac_flag=0,ip_src_flag=0,ip_dst_flag=0;
ret = rte_eal_init(argc, argv);
if (ret < 0)
rte_panic("Cannot init EAL\n");
argc -= ret;
argv += ret;
while ((c = getopt(argc, argv, "m:s:d:h")) != -1)
switch(c) {
case 'm':
// note, not quite sure why last two bytes are zero, but that is how DPDK likes it
DST_MAC=0ULL;
DST_MAC=string_to_mac(optarg)<<16;
mac_flag=1;
break;
case 's':
IP_SRC_ADDR=string_to_ip(optarg);
ip_src_flag=1;
break;
case 'd':
IP_DST_ADDR=string_to_ip(optarg);
ip_dst_flag=1;
break;
case 'h':
printf("usage -- -m [dst MAC] -s [src IP] -d [dst IP]\n");
exit(0);
break;
}
if(mac_flag==0) {
fprintf(stderr, "missing -m for destination MAC adress\n");
exit(1);
}
if(ip_src_flag==0) {
fprintf(stderr, "missing -s for IP source adress\n");
exit(1);
}
if(ip_dst_flag==0) {
fprintf(stderr, "missing -d for IP destination adress\n");
exit(1);
}
/* Creates a new mempool in memory to hold the mbufs. */
mbuf_pool = rte_pktmbuf_pool_create("MBUF_POOL", NUM_MBUFS,
MBUF_CACHE_SIZE, 0, RTE_MBUF_DEFAULT_BUF_SIZE, rte_socket_id());
if (mbuf_pool == NULL)
rte_exit(EXIT_FAILURE, "Cannot create mbuf pool\n");
// initialize port 0
if (port_init(0,mbuf_pool) != 0)
rte_exit(EXIT_FAILURE, "Cannot init port 0\n");
/* Initialize all ports. */
if (port_init(1, mbuf_pool) != 0)
rte_exit(EXIT_FAILURE, "Cannot init port %"PRIu16 "\n",
1);
pkt_data_len = (uint16_t) (TX_PACKET_LENGTH - (sizeof(struct rte_ether_hdr) +
sizeof(struct rte_ipv4_hdr) +
sizeof(struct rte_udp_hdr)));
setup_pkt_udp_ip_headers(&pkt_ip_hdr, &pkt_udp_hdr, pkt_data_len);
packetsend_withSequence();
// send_packet();
return(0);
}

Related

interrupts not working in KVM x86 16-bit guest

I'm writing a Linux KVM hypervisor for x86 16-bit guests running in real mode. When doing interrupt calls (int ... instruction), I've encountered the KVM_INTERNAL_ERROR_SIMUL_EX error on Linux kernel 3.13.0. The same code is running fine on Linux kernel 3.16.0. Am I missing something? Is there a workaround I can add to my code to make it work with Linux kernel 3.13.0 (and possibly earlier)?
The test guest calls int 0x18 ... int 0x4f, all of which is handled in the hypervisor (C code after KVM_RUN has returned). When it's working correctly, all of the interrupt calls work. On Linux kernel 3.13.0, int 0x21 starts failing (and then int 0x22, int 0x23 and int 0x24 would also fail).
I was trying to write the shortest example C code to demonstrate the problem, here it is:
/* Based on: https://gist.github.com/zserge/d68683f17c68709818f8baab0ded2d15
* Based on: https://gist.githubusercontent.com/zserge/d68683f17c68709818f8baab0ded2d15/raw/b79033254b092ec9121bb891938b27dd128030d7/kvm-host-simple.c
*
* Compile: gcc -ansi -pedantic -s -O2 -W -Wall -o kvm16 kvm16.c && ./kvm16
*
* Expected correct output (e.g. on Linux 3.16.0 compiled for i386 (i686)):
*
* ...
* info: int 0x4f iret to: ...
* info: success, exiting
*
* Failure output (e.g. on Linux 3.13.0 compiled for amd64 (x86_64)):
*
* info: int 0x20 iret to: cs=0x0070 ip=0x0013
* fatal: KVM internal error suberror=2
*
* // Encounter unexpected simultaneous exceptions.
* #define KVM_INTERNAL_ERROR_SIMUL_EX 2
*/
#define _GNU_SOURCE
#include <fcntl.h>
#include <linux/kvm.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <unistd.h>
#define INT_NUM 0x21 /* Also works for INT_NUM == 0x20. */
int main(int argc, char *argv[]) {
int kvm_fd, vm_fd, vcpu_fd;
void *mem;
struct kvm_userspace_memory_region region;
struct kvm_run *run;
struct kvm_regs regs;
struct kvm_sregs sregs;
(void)argc; (void)argv;
if ((kvm_fd = open("/dev/kvm", O_RDWR)) < 0) {
perror("failed to open /dev/kvm");
return 1;
}
if ((vm_fd = ioctl(kvm_fd, KVM_CREATE_VM, 0)) < 0) {
perror("failed to create vm");
return 1;
}
if ((mem = mmap(NULL, 0x1000, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE, -1, 0)) == NULL) {
perror("mmap");
return 1;
}
memset(&region, 0, sizeof(region));
region.slot = 0;
region.guest_phys_addr = 0;
region.memory_size = 0x1000;
region.userspace_addr = (uintptr_t)mem;
if (ioctl(vm_fd, KVM_SET_USER_MEMORY_REGION, &region) < 0) {
perror("KVM_SET_USER_MEMORY_REGION");
return 1;
}
{ /* 8086 real mode machine code. */
char *p = (char*)mem + 0x700;
unsigned int_num;
for (int_num = 0; int_num < 0x100; ++int_num) {
*(unsigned short*)((char*)mem + int_num * 4) = int_num; /* Interrupt vector INT_NUM offset := INT_NUM. */
*(unsigned short*)((char*)mem + int_num * 4 + 2) = 0x54; /* Interrupt vector INT_NUM segment := 0x54. */
}
*p++ = (char)0xf4; /* hlt. */
for (int_num = 0x18; int_num < 0x50; ++int_num) {
*p++ = (char)0xcd; /* int int_num. */
*p++ = (char)int_num;
}
*p++ = (char)0xf4;
}
memset((char*)mem + 0x540, '\xf4', 0x100); /* 256 times hlt. Interrupt vectors point here. */
if ((vcpu_fd = ioctl(vm_fd, KVM_CREATE_VCPU, 0)) < 0) {
perror("KVM_CREATE_VCPU");
return 1;
}
{
int kvm_run_mmap_size = ioctl(kvm_fd, KVM_GET_VCPU_MMAP_SIZE, 0);
if (kvm_run_mmap_size < 0) {
perror("KVM_GET_VCPU_MMAP_SIZE");
return 1;
}
run = (struct kvm_run *)mmap(
NULL, kvm_run_mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED, vcpu_fd, 0);
if (run == NULL) {
perror("mmap kvm_run");
return 1;
}
}
memset(&regs, '\0', sizeof(regs));
if (ioctl(vcpu_fd, KVM_GET_SREGS, &sregs) < 0) {
perror("KVM_GET_SREGS");
return 1;
}
{
int fd = open("kvm16.sregs", O_CREAT | O_WRONLY | O_TRUNC, 0644);
if (fd < 0) {
perror("open");
return 1;
}
if (write(fd, &sregs, sizeof(sregs)) != sizeof(sregs)) {
perror("write");
return 1;
}
if (close(fd) != 0) {
perror("close");
return 1;
}
}
sregs.cs.base = (sregs.cs.selector = 0x70) << 4;
sregs.ds.base = (sregs.ds.selector = sregs.cs.selector) << 4;
sregs.es.base = (sregs.es.selector = sregs.cs.selector) << 4;
sregs.ss.base = (sregs.ss.selector = sregs.cs.selector) << 4;
if (ioctl(vcpu_fd, KVM_GET_REGS, &regs) < 0) {
perror("KVM_GET_REGS");
return 1;
}
regs.rflags = 1 << 1; /* Reserved bit in EFLAGS. Even needed after KVM_GET_REGS. */
regs.rip = 0;
regs.rsp = 0x1000 - 0x700;
if (ioctl(vcpu_fd, KVM_SET_SREGS, &sregs) < 0) {
perror("KVM_SET_SREGS");
return 1;
}
if (ioctl(vcpu_fd, KVM_SET_REGS, &regs) < 0) {
perror("KVM_SET_REGS");
return 1;
}
for (;;) {
int ret = ioctl(vcpu_fd, KVM_RUN, 0);
unsigned short cs, ip;
if (ret < 0) {
perror("KVM_RUN");
return 1;
}
if (ioctl(vcpu_fd, KVM_GET_SREGS, &sregs) < 0) {
perror("KVM_GET_SREGS");
return 1;
}
if (ioctl(vcpu_fd, KVM_GET_REGS, &regs) < 0) {
perror("KVM_GET_REGS");
return 1;
}
cs = sregs.cs.selector;
ip = regs.rip;
if (run->exit_reason == KVM_EXIT_HLT) {
fprintf(stderr, "info: hlt: cs=0x%04x ip=0x%04x\n", cs, ip - 1);
if (cs == 0x70) {
if (ip != 0 + 1) {
fprintf(stderr, "info: success, exiting\n");
return 0; /* EXIT_SUCCESS after the second `hlt' in the code. */
}
} else if (cs == 0x54) { /* Simulate iret. */
const char *csip_ptr = (const char*)mem + ((unsigned short)sregs.ss.selector << 4) + (unsigned short)regs.rsp;
const unsigned short int_ip = ((const unsigned short*)csip_ptr)[0];
const unsigned short int_cs = ((const unsigned short*)csip_ptr)[1];
const unsigned short int_flags = ((const unsigned short*)csip_ptr)[2];
fprintf(stderr, "info: int 0x%02x iret to: cs=0x%04x ip=0x%04x\n", ip - 1, int_cs, int_ip);
sregs.cs.base = (sregs.cs.selector = int_cs) << 4;
regs.rip = int_ip;
if (int_flags & (1 << 9)) regs.rflags |= (1 << 9); /* Set IF back to 1 if it was 1. */
regs.rsp += 6; /* pop ip, pop cs, popfw . */
if (ioctl(vcpu_fd, KVM_SET_SREGS, &sregs) < 0) {
perror("KVM_SET_SREGS");
return 1;
}
if (ioctl(vcpu_fd, KVM_SET_REGS, &regs) < 0) {
perror("KVM_SET_REGS");
return 1;
}
} else {
fprintf(stderr, "fatal: unexpected hlt: cs=0x%04x ip=0x%04x\n", cs, ip - 1);
return 5;
}
} else if (run->exit_reason == KVM_EXIT_INTERNAL_ERROR) {
fprintf(stderr, "fatal: KVM internal error suberror=%d\n", (unsigned)run->internal.suberror);
return 4;
} else {
fprintf(stderr, "fatal: unexpected KVM exit: exit_reason=%d cs=0x%04x ip=0x%04x\n", run->exit_reason, cs, ip);
return 2;
}
}
}

Execute mmap on Linux kernel

I'm trying to enable pull-ups on Raspberry pi and the easier way to do it it's executing raspi-gpio set <gpio> <pu/pd>, the problem is that for some reason I can't do it with call_usermodehelper (it doesn't throw any error, but it does nothing).
As an alternative I've been looking at raspi-gpio source code and I have a functional C code that enables pull-ups (this code prints the GPIO CPU and enable GPIO26's pull-ups):
#include <stdio.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdlib.h>
#include <ctype.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <time.h>
// From https://github.com/RPi-Distro/raspi-gpio/blob/master/raspi-gpio.c
#define PULL_UNSET -1
#define PULL_NONE 0
#define PULL_DOWN 1
#define PULL_UP 2
#define GPIO_BASE_OFFSET 0x00200000
#define GPPUD 37
#define GPPUDCLK0 38
uint32_t getGpioRegBase(void) {
const char *revision_file = "/proc/device-tree/system/linux,revision";
uint8_t revision[4] = { 0 };
uint32_t cpu = 0;
FILE *fd;
if ((fd = fopen(revision_file, "rb")) == NULL)
{
printf("Can't open '%s'\n", revision_file);
}
else
{
if (fread(revision, 1, sizeof(revision), fd) == 4)
cpu = (revision[2] >> 4) & 0xf;
else
printf("Revision data too short\n");
fclose(fd);
}
printf("CPU: %d\n", cpu);
switch (cpu) {
case 0: // BCM2835 [Pi 1 A; Pi 1 B; Pi 1 B+; Pi Zero; Pi Zero W]
return 0x20000000 + GPIO_BASE_OFFSET;
case 1: // BCM2836 [Pi 2 B]
case 2: // BCM2837 [Pi 3 B; Pi 3 B+; Pi 3 A+]
return 0x3f000000 + GPIO_BASE_OFFSET;
case 3: // BCM2711 [Pi 4 B]
return 0xfe000000 + GPIO_BASE_OFFSET;
default:
printf("Unrecognised revision code\n");
exit(1);
}
}
volatile uint32_t *getBase(uint32_t reg_base) {
int fd;
if ((fd = open ("/dev/mem", O_RDWR | O_SYNC | O_CLOEXEC) ) < 0) return NULL;
return (uint32_t *)mmap(0, /*chip->reg_size*/ 0x1000,
PROT_READ|PROT_WRITE, MAP_SHARED,
fd, reg_base);
}
void setPull(volatile uint32_t *base, unsigned int gpio, int pull) {
int clkreg = GPPUDCLK0 + (gpio / 32);
int clkbit = 1 << (gpio % 32);
base[GPPUD] = pull;
usleep(10);
base[clkreg] = clkbit;
usleep(10);
base[GPPUD] = 0;
usleep(10);
base[clkreg] = 0;
usleep(10);
}
int main() {
uint32_t reg_base = getGpioRegBase();
volatile uint32_t *base = getBase(reg_base);
if (base == NULL || base == (uint32_t *)-1) {
printf("Base error");
return 1;
}
printf("Base: %p\n", base);
setPull(base, 26, PULL_UP);
return 0;
}
Now obviously I need to convert that code to kernel code. I've been doing great with delays and files, but I have no idea what to do with mmap (I've never seen it before and I don't know exactly what it does, all I know it's that it maps memory).
#include <linux/types.h> // uint_32
#include <linux/fs.h> // filp_open/filp_close
#include <linux/delay.h> // delay
#define PULL_DOWN 1
#define PULL_UP 2
#define GPIO_BASE_OFFSET 0x00200000
#define GPPUD 37
#define GPPUDCLK0 38
static uint32_t getGpioRegBase(bool *error) {
uint8_t revision[4] = { 0 };
uint32_t cpu = 0;
struct file *fd;
ssize_t rc = 0;
if (IS_ERR(( fd = filp_open("/proc/device-tree/system/linux,revision", O_RDONLY | O_SYNC | O_CLOEXEC, 0) ))) {
*error = true;
return 0;
}
if ((rc = kernel_read(fd, revision, sizeof(revision), 0)) == 4) cpu = (revision[2] >> 4) & 0xf;
else {
*error = true;
return 0;
}
filp_close(fd, NULL);
*error = false;
switch (cpu) {
case 0: // BCM2835 [Pi 1 A; Pi 1 B; Pi 1 B+; Pi Zero; Pi Zero W]
return 0x20000000 + GPIO_BASE_OFFSET;
case 1: // BCM2836 [Pi 2 B]
case 2: // BCM2837 [Pi 3 B; Pi 3 B+; Pi 3 A+]
return 0x3f000000 + GPIO_BASE_OFFSET;
case 3: // BCM2711 [Pi 4 B]
return 0xfe000000 + GPIO_BASE_OFFSET;
default:
*error = true;
return 0;
}
}
static volatile uint32_t *getBase(uint32_t reg_base) {
struct file *fd;
volatile uint32_t *r;
if (IS_ERR(( fd = filp_open("/dev/mem", O_RDWR | O_SYNC | O_CLOEXEC, 0) ))) return NULL;
r = (uint32_t*)mmap(0, 0x1000, PROT_READ|PROT_WRITE, MAP_SHARED, fd, reg_base);
filp_close(fd, NULL); // TODO the original didn't have this
return r;
}
static void setPull(volatile uint32_t *base, uint32_t gpio, int pull) {
int clkreg = GPPUDCLK0 + (gpio / 32);
int clkbit = 1 << (gpio % 32);
base[GPPUD] = pull;
udelay(10);
base[clkreg] = clkbit;
udelay(10);
base[GPPUD] = 0;
udelay(10);
base[clkreg] = 0;
udelay(10);
}
/**
* Equivalent to 'raspi-gpio set <gpio> <pu/pd>'
* #param gpio Valid GPIO pin
* #param pull PULL_DOWN/PULL_UP
*/
static int setGpioPull(uint32_t gpio, int pull) {
bool error;
uint32_t reg_base;
volatile uint32_t *base;
reg_base = getGpioRegBase(&error);
if (error) return -1;
base = getBase(reg_base);
if (base == NULL || base == (uint32_t*)-1) return -1;
setPull(base, gpio, pull);
return 0;
}
All I've found it's a function declaration (int (*mmap) (struct file *filp, struct vm_area_struct *vma)), but I don't know how to send any of the arguments nor the return value that mmap (caddr_t addr, size_t len, int prot, int flags, int fd, off_t offset) uses.
Thanks in advance!
Mmap was accessing to "/dev/mem", after some more questions I've found that that file connects user-space with kernel-space (and LKM it's on kernel space, so no need to access to it). In this case, ioremap does the job.
Here's the final code:
#include <linux/types.h> // uint_32
#include <linux/fs.h> // filp_open/filp_close
#include <linux/delay.h> // udelay
#include <linux/io.h> // ioremap?
#define PULL_DOWN 1
#define PULL_UP 2
/**
* Equivalent to 'raspi-gpio set <gpio> <pu/pd>'
* #param gpio Valid GPIO pin
* #param pull PULL_DOWN/PULL_UP
*/
static int setGpioPull(uint32_t gpio, int pull);
/****************************
*** PRIVATE FUNCTIONS ***
****************************/
#define GPIO_BASE_OFFSET 0x00200000
#define GPPUD 37
#define GPPUDCLK0 38
static uint32_t getGpioRegBase(bool *error) {
uint8_t revision[4] = { 0 };
uint32_t cpu = 0;
struct file *fd;
ssize_t rc = 0;
if (IS_ERR(( fd = filp_open("/proc/device-tree/system/linux,revision", O_RDONLY | O_SYNC | O_CLOEXEC, 0) ))) {
*error = true;
return 0;
}
if ((rc = kernel_read(fd, revision, sizeof(revision), 0)) == 4) cpu = (revision[2] >> 4) & 0xf;
else {
*error = true;
return 0;
}
filp_close(fd, NULL);
*error = false;
switch (cpu) {
case 0: // BCM2835 [Pi 1 A; Pi 1 B; Pi 1 B+; Pi Zero; Pi Zero W]
return 0x20000000 + GPIO_BASE_OFFSET;
case 1: // BCM2836 [Pi 2 B]
case 2: // BCM2837 [Pi 3 B; Pi 3 B+; Pi 3 A+]
return 0x3f000000 + GPIO_BASE_OFFSET;
case 3: // BCM2711 [Pi 4 B]
return 0xfe000000 + GPIO_BASE_OFFSET;
default:
*error = true;
return 0;
}
}
static void setPull(volatile uint32_t *base, uint32_t gpio, int pull) {
int clkreg = GPPUDCLK0 + (gpio / 32);
int clkbit = 1 << (gpio % 32);
base[GPPUD] = pull;
udelay(10);
base[clkreg] = clkbit;
udelay(10);
base[GPPUD] = 0;
udelay(10);
base[clkreg] = 0;
udelay(10);
}
static int setGpioPull(uint32_t gpio, int pull) {
bool error;
uint32_t reg_base;
volatile uint32_t *base;
reg_base = getGpioRegBase(&error);
if (error) return -1;
base = (uint32_t*)ioremap(reg_base, 0x1000);
if (base == NULL || base == (uint32_t*)-1) return -1;
setPull(base, gpio, pull);
iounmap(base);
return 0;
}

Issue while reading registers from modbus slave written in pymodbus and modbus master in C

I am trying to create a modbus master slave model. I have written modbus slave using pymodbus and modbus master is using c libmodbus.
Slave is having a bunch of register set and register 0 is having value as
register 0, number of register 2, type hex, value 45565345
register 2, number of register 4, type hex, value 10002
I am using modbus over TCP
Below is the c code
/*
* Copyright © 2008-2014 Stéphane Raimbault <stephane.raimbault#gmail.com>
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <modbus.h>
#include "unit-test.h"
const int EXCEPTION_RC = 2;
enum {
TCP,
TCP_PI,
RTU
};
int test_server(modbus_t *ctx, int use_backend);
int send_crafted_request(modbus_t *ctx, int function,
uint8_t *req, int req_size,
uint16_t max_value, uint16_t bytes,
int backend_length, int backend_offset);
int equal_dword(uint16_t *tab_reg, const uint32_t value);
#define BUG_REPORT(_cond, _format, _args ...) \
printf("\nLine %d: assertion error for '%s': " _format "\n", __LINE__, # _cond, ## _args)
#define ASSERT_TRUE(_cond, _format, __args...) { \
if (_cond) { \
printf("OK\n"); \
} else { \
BUG_REPORT(_cond, _format, ## __args); \
goto close; \
} \
};
int equal_dword(uint16_t *tab_reg, const uint32_t value) {
return ((tab_reg[0] == (value >> 16)) && (tab_reg[1] == (value & 0xFFFF)));
}
int main(int argc, char *argv[])
{
const int NB_REPORT_SLAVE_ID = 10;
uint8_t *tab_rp_bits = NULL;
uint16_t *tab_rp_registers = NULL;
uint16_t *tab_rp_registers_bad = NULL;
modbus_t *ctx = NULL;
int i;
uint8_t value;
int nb_points;
int rc;
float real;
uint32_t old_response_to_sec;
uint32_t old_response_to_usec;
uint32_t new_response_to_sec;
uint32_t new_response_to_usec;
uint32_t old_byte_to_sec;
uint32_t old_byte_to_usec;
int use_backend;
int success = FALSE;
int old_slave;
if (argc > 1) {
if (strcmp(argv[1], "tcp") == 0) {
use_backend = TCP;
} else if (strcmp(argv[1], "tcppi") == 0) {
use_backend = TCP_PI;
} else if (strcmp(argv[1], "rtu") == 0) {
use_backend = RTU;
} else {
printf("Usage:\n %s [tcp|tcppi|rtu] - Modbus client for unit testing\n\n", argv[0]);
exit(1);
}
} else {
/* By default */
use_backend = TCP;
}
if (use_backend == TCP) {
ctx = modbus_new_tcp("127.0.0.1", 1520);
} else if (use_backend == TCP_PI) {
ctx = modbus_new_tcp_pi("::1", "1520");
} else {
ctx = modbus_new_rtu("/dev/ttyUSB1", 115200, 'N', 8, 1);
}
if (ctx == NULL) {
fprintf(stderr, "Unable to allocate libmodbus context\n");
return -1;
}
modbus_set_debug(ctx, TRUE);
modbus_set_error_recovery(ctx,
MODBUS_ERROR_RECOVERY_LINK |
MODBUS_ERROR_RECOVERY_PROTOCOL);
if (use_backend == RTU) {
modbus_set_slave(ctx, SERVER_ID);
}
modbus_get_response_timeout(ctx, &old_response_to_sec, &old_response_to_usec);
if (modbus_connect(ctx) == -1) {
fprintf(stderr, "Connection failed: %s\n", modbus_strerror(errno));
modbus_free(ctx);
return -1;
}
modbus_get_response_timeout(ctx, &new_response_to_sec, &new_response_to_usec);
printf("** UNIT TESTING **\n");
rc = modbus_read_registers(ctx, 0x02,
2, tab_rp_registers);
printf(" value %d" , tab_rp_registers[0]);
modbus_close(ctx);
modbus_free(ctx);
ctx = NULL;
close:
/* Free the memory */
free(tab_rp_bits);
free(tab_rp_registers);
/* Close the connection */
modbus_close(ctx);
modbus_free(ctx);
return (success) ? 0 : -1;
}
/* Send crafted requests to test server resilience
and ensure proper exceptions are returned. */
int test_server(modbus_t *ctx, int use_backend)
{
int rc;
int i;
/* Read requests */
const int READ_RAW_REQ_LEN = 6;
const int slave = (use_backend == RTU) ? SERVER_ID : MODBUS_TCP_SLAVE;
uint8_t read_raw_req[] = {
slave,
/* function, address, 5 values */
MODBUS_FC_READ_HOLDING_REGISTERS,
UT_REGISTERS_ADDRESS >> 8, UT_REGISTERS_ADDRESS & 0xFF,
0x0, 0x05
};
/* Write and read registers request */
const int RW_RAW_REQ_LEN = 13;
uint8_t rw_raw_req[] = {
slave,
/* function, addr to read, nb to read */
MODBUS_FC_WRITE_AND_READ_REGISTERS,
/* Read */
UT_REGISTERS_ADDRESS >> 8, UT_REGISTERS_ADDRESS & 0xFF,
(MODBUS_MAX_WR_READ_REGISTERS + 1) >> 8,
(MODBUS_MAX_WR_READ_REGISTERS + 1) & 0xFF,
/* Write */
0, 0,
0, 1,
/* Write byte count */
1 * 2,
/* One data to write... */
0x12, 0x34
};
const int WRITE_RAW_REQ_LEN = 13;
uint8_t write_raw_req[] = {
slave,
/* function will be set in the loop */
MODBUS_FC_WRITE_MULTIPLE_REGISTERS,
/* Address */
UT_REGISTERS_ADDRESS >> 8, UT_REGISTERS_ADDRESS & 0xFF,
/* 3 values, 6 bytes */
0x00, 0x03, 0x06,
/* Dummy data to write */
0x02, 0x2B, 0x00, 0x01, 0x00, 0x64
};
const int INVALID_FC = 0x42;
const int INVALID_FC_REQ_LEN = 6;
uint8_t invalid_fc_raw_req[] = {
slave, 0x42, 0x00, 0x00, 0x00, 0x00
};
int req_length;
uint8_t rsp[MODBUS_TCP_MAX_ADU_LENGTH];
int tab_read_function[] = {
MODBUS_FC_READ_COILS,
MODBUS_FC_READ_DISCRETE_INPUTS,
MODBUS_FC_READ_HOLDING_REGISTERS,
MODBUS_FC_READ_INPUT_REGISTERS
};
int tab_read_nb_max[] = {
MODBUS_MAX_READ_BITS + 1,
MODBUS_MAX_READ_BITS + 1,
MODBUS_MAX_READ_REGISTERS + 1,
MODBUS_MAX_READ_REGISTERS + 1
};
int backend_length;
int backend_offset;
if (use_backend == RTU) {
backend_length = 3;
backend_offset = 1;
} else {
backend_length = 7;
backend_offset = 7;
}
printf("\nTEST RAW REQUESTS:\n");
uint32_t old_response_to_sec;
uint32_t old_response_to_usec;
/* This requests can generate flushes server side so we need a higher
* response timeout than the server. The server uses the defined response
* timeout to sleep before flushing.
* The old timeouts are restored at the end.
*/
modbus_get_response_timeout(ctx, &old_response_to_sec, &old_response_to_usec);
modbus_set_response_timeout(ctx, 0, 600000);
req_length = modbus_send_raw_request(ctx, read_raw_req, READ_RAW_REQ_LEN);
printf("* modbus_send_raw_request: ");
ASSERT_TRUE(req_length == (backend_length + 5), "FAILED (%d)\n", req_length);
printf("* modbus_receive_confirmation: ");
rc = modbus_receive_confirmation(ctx, rsp);
ASSERT_TRUE(rc == (backend_length + 12), "FAILED (%d)\n", rc);
/* Try to read more values than a response could hold for all data
types. */
for (i=0; i<4; i++) {
rc = send_crafted_request(ctx, tab_read_function[i],
read_raw_req, READ_RAW_REQ_LEN,
tab_read_nb_max[i], 0,
backend_length, backend_offset);
if (rc == -1)
goto close;
}
/* Modbus write and read multiple registers */
rc = send_crafted_request(ctx, MODBUS_FC_WRITE_AND_READ_REGISTERS,
rw_raw_req, RW_RAW_REQ_LEN,
MODBUS_MAX_WR_READ_REGISTERS + 1, 0,
backend_length, backend_offset);
if (rc == -1)
goto close;
/* Modbus write multiple registers with large number of values but a set a
small number of bytes in requests (not nb * 2 as usual). */
rc = send_crafted_request(ctx, MODBUS_FC_WRITE_MULTIPLE_REGISTERS,
write_raw_req, WRITE_RAW_REQ_LEN,
MODBUS_MAX_WRITE_REGISTERS + 1, 6,
backend_length, backend_offset);
if (rc == -1)
goto close;
rc = send_crafted_request(ctx, MODBUS_FC_WRITE_MULTIPLE_COILS,
write_raw_req, WRITE_RAW_REQ_LEN,
MODBUS_MAX_WRITE_BITS + 1, 6,
backend_length, backend_offset);
if (rc == -1)
goto close;
/* Test invalid function code */
modbus_send_raw_request(ctx, invalid_fc_raw_req, INVALID_FC_REQ_LEN * sizeof(uint8_t));
rc = modbus_receive_confirmation(ctx, rsp);
printf("Return an exception on unknown function code: ");
ASSERT_TRUE(rc == (backend_length + EXCEPTION_RC) &&
rsp[backend_offset] == (0x80 + INVALID_FC), "")
modbus_set_response_timeout(ctx, old_response_to_sec, old_response_to_usec);
return 0;
close:
modbus_set_response_timeout(ctx, old_response_to_sec, old_response_to_usec);
return -1;
}
int send_crafted_request(modbus_t *ctx, int function,
uint8_t *req, int req_len,
uint16_t max_value, uint16_t bytes,
int backend_length, int backend_offset)
{
uint8_t rsp[MODBUS_TCP_MAX_ADU_LENGTH];
int j;
for (j=0; j<2; j++) {
int rc;
req[1] = function;
if (j == 0) {
/* Try to read or write zero values on first iteration */
req[4] = 0x00;
req[5] = 0x00;
if (bytes) {
/* Write query */
req[6] = 0x00;
}
} else {
/* Try to read or write max values + 1 on second iteration */
req[4] = (max_value >> 8) & 0xFF;
req[5] = max_value & 0xFF;
if (bytes) {
/* Write query (nb values * 2 to convert in bytes for registers) */
req[6] = bytes;
}
}
modbus_send_raw_request(ctx, req, req_len * sizeof(uint8_t));
if (j == 0) {
printf("* try function 0x%X: %s 0 values: ", function, bytes ? "write": "read");
} else {
printf("* try function 0x%X: %s %d values: ", function, bytes ? "write": "read",
max_value);
}
rc = modbus_receive_confirmation(ctx, rsp);
ASSERT_TRUE(rc == (backend_length + EXCEPTION_RC) &&
rsp[backend_offset] == (0x80 + function) &&
rsp[backend_offset + 1] == MODBUS_EXCEPTION_ILLEGAL_DATA_VALUE, "");
}
return 0;
close:
return -1;
}
I am getting below output from modbus master
Connecting to 127.0.0.1:1520
** UNIT TESTING **
[00][01][00][00][00][06][FF][03][00][02][00][02]
Waiting for a confirmation...
<00><01><00><00><00><07><FF><03><04><00><01><00><02>
Segmentation fault (core dumped)
Output on modbus slave
DEBUG:pymodbus.server.async:Client Connected [IPv4Address(type='TCP', host='127.0.0.1', port=1520)]
DEBUG:pymodbus.server.async:Data Received: 0x0 0x1 0x0 0x0 0x0 0x6 0xff 0x3 0x0 0x2 0x0 0x2
DEBUG:pymodbus.framer.socket_framer:Processing: 0x0 0x1 0x0 0x0 0x0 0x6 0xff 0x3 0x0 0x2 0x0 0x2
DEBUG:pymodbus.factory:Factory Request[3]
DEBUG:pymodbus.datastore.context:validate[3] 3:2
DEBUG:pymodbus.datastore.context:getValues[3] 3:2
DEBUG:pymodbus.datastore.context:xxxxxxxxxxxxxxxxxxxxxxxxx
DEBUG:pymodbus.datastore.context:[1, 2]
DEBUG:pymodbus.server.async:send: 000100000007ff030400010002
DEBUG:pymodbus.server.async:Client Disconnected: [Failure instance: Traceback (failure with no frames): <class 'twisted.internet.error.ConnectionDone'>: Connection was closed cleanly.
I am trying to retrieve value of the register. Not sure why I am not getting the value
I have never used this stack but RTFM says:
int modbus_read_registers(modbus_t *ctx, int addr, int nb, uint16_t *dest);
...
You must take care to allocate enough memory to store the results in dest (at least nb * sizeof(uint16_t)).
But tab_rp_registers is set to NULL and never allocated.

DPDK create a packet for transmission

I am new to DPDK and trying to create a packet to send it from one DPDK enabled machine to another connected directly via an ethernet. I modified an example/rxtx_callbacks/main.c provided with DPDK at both side. However, I am not receiving anything at the receiver. What wrong am I doing?
Modified function at transmitter: lcore_main is modified:
static __attribute__((noreturn)) void lcore_main()
{
uint16_t port;
struct ether_hdr *eth_hdr;
struct ether_addr daddr;
daddr.addr_bytes[0] = 116;
daddr.addr_bytes[1] = 225;
daddr.addr_bytes[2] = 228;
daddr.addr_bytes[3] = 204;
daddr.addr_bytes[4] = 106;
daddr.addr_bytes[5] = 82;
//rte_eth_macaddr_get(portid, &addr);
struct ipv4_hdr *ipv4_hdr;
int32_t i;
int ret;
RTE_ETH_FOREACH_DEV(port)
if (rte_eth_dev_socket_id(port) > 0 &&
rte_eth_dev_socket_id(port) !=
(int)rte_socket_id())
printf("WARNING, port %u is on remote NUMA node to "
"polling thread.\n\tPerformance will "
"not be optimal.\n", port);
printf("\nCore %u forwarding packets. [Ctrl+C to quit]\n",
rte_lcore_id());
//struct rte_mbuf *m_head = rte_pktmbuf_alloc(mbuf_pool);
struct rte_mbuf *m_head[BURST_SIZE];
for (;;) {
RTE_ETH_FOREACH_DEV(port) {
if(rte_pktmbuf_alloc_bulk(mbuf_pool, m_head, BURST_SIZE)!=0)
{
printf("Allocation problem\n");
}
for(i = 0; i < BURST_SIZE; i++) {
eth_hdr = rte_pktmbuf_mtod(m_head[i], struct ether_hdr *);
//eth_hdr = (struct ether_hdr *)rte_pktmbuf_append(m_head[i],
// sizeof(struct ether_hdr));
eth_hdr->ether_type = htons(ETHER_TYPE_IPv4);
rte_memcpy(&(eth_hdr->s_addr), &addr, sizeof(struct ether_addr));
rte_memcpy(&(eth_hdr->d_addr), &daddr, sizeof(struct ether_addr));
}
const uint16_t nb_tx = rte_eth_tx_burst(port, 0, m_head, BURST_SIZE);
if (unlikely(nb_tx < BURST_SIZE)) {
uint16_t buf;
for (buf = nb_tx; buf < BURST_SIZE; buf++)
rte_pktmbuf_free(m_head[buf]);
}
}
}
}
receiver side RTE_ETH_FOREACH_DEV of tx part is modified to:
RTE_ETH_FOREACH_DEV(port) {
struct rte_mbuf *bufs[BURST_SIZE];
const uint16_t nb_rx = rte_eth_rx_burst(port, bufs, BURST_SIZE);
//printf("Number of Packets received %d\n", nb_rx);
for(i = 0; i < nb_rx; i++) {
//ipv4_hdr = rte_pktmbuf_mtod_offset(bufs[i], struct ipv4_hdr *,
// sizeof(struct ether_hdr));
//printf("Packet ip received %d\n", ipv4_hdr->src_addr);
eth_hdr = rte_pktmbuf_mtod(bufs[i], struct ether_hdr *);
printf("Packet ip received %d\n", eth_hdr->ether_type);
}
if (unlikely(nb_rx == 0))
continue;
const uint16_t nb_tx = 0; // = rte_eth_tx_burst(port ^ 1, 0, bufs, nb_rx);
if (unlikely(nb_tx < nb_rx)) {
uint16_t buf;
for (buf = nb_tx; buf < nb_rx; buf++)
rte_pktmbuf_free(bufs[buf]);
}
}
Please let me know if I missed something.
There are few issues with the code:
eth_hdr = rte_pktmbuf_mtod(m_head[i], struct ether_hdr *);
Unlike rte_pktmbuf_append(), the rte_pktmbuf_mtod() does not change the packet length, so it should be set manually before the tx.
eth_hdr->ether_type = htons(ETHER_TYPE_IPv4);
If we set ETHER_TYPE_IPv4, a correct IPv4 header must follow. So we need either to add the header or to change the ether_type.
rte_memcpy(&(eth_hdr->s_addr), &addr, sizeof(struct ether_addr));
Where is the source address comes from?
const uint16_t nb_tx = rte_eth_tx_burst(port, 0, m_head, BURST_SIZE);
Looks like we transmit a burst of zero-sized packets with invalid IPv4 headers. Please also make sure the source/destination addresses are correct.
As suggested by #andriy-berestovsky, I used rte_eth_stats_get() and it shows packets are present in ethernet ring via the field ipackets but rte_eth_rx_burst is not returning any packets. Full code is included here, please let me know what I am doing wrong. (I am using testpmd at transmitter side)
#include <stdint.h>
#include <inttypes.h>
#include <rte_eal.h>
#include <rte_ethdev.h>
#include <rte_ether.h>
#include <rte_cycles.h>
#include <rte_lcore.h>
#include <rte_ip.h>
#include <rte_mbuf.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <signal.h>
#define MAX_SOURCE_SIZE (0x100000)
#define RX_RING_SIZE 1024
#define TX_RING_SIZE 1024
#define NUM_MBUFS 8191
#define MBUF_CACHE_SIZE 250
#define BURST_SIZE 32
static const struct rte_eth_conf port_conf_default = {
.rxmode = {
.max_rx_pkt_len = ETHER_MAX_LEN,
},
};
static struct {
uint64_t total_cycles;
uint64_t total_pkts;
} latency_numbers;
static volatile bool force_quit;
struct rte_mempool *mbuf_pool;
static void
signal_handler(int signum)
{
struct rte_eth_stats eth_stats;
int i;
if (signum == SIGINT || signum == SIGTERM) {
printf("\n\nSignal %d received, preparing to exit...\n",
signum);
RTE_ETH_FOREACH_DEV(i) {
rte_eth_stats_get(i, &eth_stats);
printf("Total number of packets received %llu, dropped rx full %llu and rest= %llu, %llu, %llu\n", eth_stats.ipackets, eth_stats.imissed, eth_stats.ierrors, eth_stats.rx_nombuf, eth_stats.q_ipackets[0]);
}
force_quit = true;
}
}
struct ether_addr addr;
/*
* Initialises a given port using global settings and with the rx buffers
* coming from the mbuf_pool passed as parameter
*/
static inline int
port_init(uint16_t port, struct rte_mempool *mbuf_pool)
{
struct rte_eth_conf port_conf = port_conf_default;
const uint16_t rx_rings = 1, tx_rings = 1;
uint16_t nb_rxd = RX_RING_SIZE;
uint16_t nb_txd = TX_RING_SIZE;
int retval;
uint16_t q;
struct rte_eth_dev_info dev_info;
struct rte_eth_txconf txconf;
if (!rte_eth_dev_is_valid_port(port))
return -1;
rte_eth_dev_info_get(port, &dev_info);
if (dev_info.tx_offload_capa & DEV_TX_OFFLOAD_MBUF_FAST_FREE)
port_conf.txmode.offloads |=
DEV_TX_OFFLOAD_MBUF_FAST_FREE;
retval = rte_eth_dev_configure(port, rx_rings, tx_rings, &port_conf);
if (retval != 0)
return retval;
retval = rte_eth_dev_adjust_nb_rx_tx_desc(port, &nb_rxd, &nb_txd);
if (retval != 0) {
printf("Error in adjustment\n");
return retval;
}
for (q = 0; q < rx_rings; q++) {
retval = rte_eth_rx_queue_setup(port, q, nb_rxd,
rte_eth_dev_socket_id(port), NULL, mbuf_pool);
if (retval < 0) {
printf("RX queue setup prob\n");
return retval;
}
}
txconf = dev_info.default_txconf;
txconf.offloads = port_conf.txmode.offloads;
for (q = 0; q < tx_rings; q++) {
retval = rte_eth_tx_queue_setup(port, q, nb_txd,
rte_eth_dev_socket_id(port), &txconf);
if (retval < 0)
return retval;
}
retval = rte_eth_dev_start(port);
if (retval < 0) {
printf("Error in start\n");
return retval;
}
rte_eth_macaddr_get(port, &addr);
printf("Port %u MAC: %02"PRIx8" %02"PRIx8" %02"PRIx8
" %02"PRIx8" %02"PRIx8" %02"PRIx8"\n",
(unsigned)port,
addr.addr_bytes[0], addr.addr_bytes[1],
addr.addr_bytes[2], addr.addr_bytes[3],
addr.addr_bytes[4], addr.addr_bytes[5]);
rte_eth_promiscuous_enable(port);
return 0;
}
/*
* Main thread that does the work, reading from INPUT_PORT
* and writing to OUTPUT_PORT
*/
static __attribute__((noreturn)) void
lcore_main(void)
{
uint16_t port;
struct ether_hdr *eth_hdr;
//struct ether_addr addr;
//rte_eth_macaddr_get(portid, &addr);
struct ipv4_hdr *ipv4_hdr;
int32_t i;
RTE_ETH_FOREACH_DEV(port)
{
if (rte_eth_dev_socket_id(port) > 0 &&
rte_eth_dev_socket_id(port) !=
(int)rte_socket_id())
printf("WARNING, port %u is on remote NUMA node to "
"polling thread.\n\tPerformance will "
"not be optimal.\n", port);
}
printf("\nCore %u forwarding packets. [Ctrl+C to quit]\n",
rte_lcore_id());
for (;;) {
RTE_ETH_FOREACH_DEV(port) {
struct rte_mbuf *bufs[BURST_SIZE];
const uint16_t nb_rx = rte_eth_rx_burst(port, 0,bufs, BURST_SIZE);
for(i = 0; i < nb_rx; i++) {
ipv4_hdr = rte_pktmbuf_mtod_offset(bufs[i], struct ipv4_hdr *, sizeof(struct ether_hdr));
printf("Packet ip received %d\n", ipv4_hdr->src_addr);
}
if (unlikely(nb_rx == 0))
continue;
const uint16_t nb_tx = 0; // = rte_eth_tx_burst(port ^ 1, 0, bufs, nb_rx);
if (unlikely(nb_tx < nb_rx)) {
uint16_t buf;
for (buf = nb_tx; buf < nb_rx; buf++)
rte_pktmbuf_free(bufs[buf]);
}
}
if(force_quit)
break;
}
}
/* Main function, does initialisation and calls the per-lcore functions */
int
main(int argc, char *argv[])
{
uint16_t nb_ports;
uint16_t portid, port;
/* init EAL */
int ret = rte_eal_init(argc, argv);
if (ret < 0)
rte_exit(EXIT_FAILURE, "Error with EAL initialization\n");
argc -= ret;
argv += ret;
force_quit = false;
signal(SIGINT, signal_handler);
signal(SIGTERM, signal_handler);
nb_ports = rte_eth_dev_count_avail();
printf("size ordered %lld\n", NUM_MBUFS *nb_ports);
mbuf_pool = rte_pktmbuf_pool_create("MBUF_POOL",
NUM_MBUFS * nb_ports, MBUF_CACHE_SIZE, 0,
RTE_MBUF_DEFAULT_BUF_SIZE, rte_socket_id());
if (nb_ports < 1)
rte_exit(EXIT_FAILURE, "Error: number of ports must be greater than %d\n", nb_ports);
if (mbuf_pool == NULL)
rte_exit(EXIT_FAILURE, "Cannot create mbuf pool\n");
// initialize all ports
RTE_ETH_FOREACH_DEV(portid)
if (port_init(portid, mbuf_pool) != 0)
rte_exit(EXIT_FAILURE, "Cannot init port %"PRIu8"\n",
portid);
if (rte_lcore_count() > 1)
printf("\nWARNING: Too much enabled lcores - "
"App uses only 1 lcore\n");
// call lcore_main on master core only
lcore_main();
return 0;
}
It seems to be a problem of ethernet card with ubuntu 14.04. With ubuntu 16.04 it is working fine.

socket programming FD_ISSET() method usage

so I'm new to socket programming, and I was asked to write the server side that sends data to a client according to a certain request. I'm trying to server multiple clients at the same time. When a client first connects, the server accepts with no troubles whatsoever, but when a client sends a certain request, I get stuck in an infinity loop and it's not clear at all to me why the server keeps sending the same info to the client over and over and over again, below is my code for the server side:
#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>
#include <math.h>
#include <windows.h>
#include <winsock.h>
#include <string.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <io.h>
#include <fstream>
#include <vector>
#define MAX_CONNECTION 100
#ifndef max
#define max(a,b) ((a) < (b) ? (a) : (b))
#endif
typedef struct connection{
char ipaddr[16];
int port;
int sd;
} connection;
static unsigned short SERVER_PORT = 4118;
int main(int argc, char* argv[])
{
int maxfd =-1;
fd_set rset, allset;
connection client[MAX_CONNECTION];
int passiveSock; /* Main Server Socket */
struct sockaddr_in servSock_in;
#ifdef WIN32
WSADATA wsaData;
WSAStartup(0x0101, &wsaData);
#endif
int port;
if (argc > 1)
port = atoi(argv[1]);
else
port = SERVER_PORT;
for(int i=0; i < MAX_CONNECTION ; i++)
client[i].sd = -1;
memset((char *)&servSock_in, 0, sizeof(servSock_in));
servSock_in.sin_family = PF_INET;
servSock_in.sin_addr.s_addr = htonl(INADDR_ANY);
servSock_in.sin_port = htons((u_short)port);
passiveSock = socket(PF_INET, SOCK_STREAM, 0);
if (passiveSock < 0) {
fprintf(stderr, "I am too tired... I failed to open gate...\n");
return -1;
}
if (bind(passiveSock, (struct sockaddr *)&servSock_in, sizeof(servSock_in)) < 0){
fprintf(stderr, "I couldn't attach gate to port...\n");
return -1;
}
if (listen(passiveSock, 5) < 0) {
fprintf(stderr, "I am not hearing anything...\n");
return -1;
}
FD_SET(passiveSock, &allset);
maxfd = max(maxfd, passiveSock);
struct sockaddr_in cliSock_in;
int cliSockLen;
int connectedSock;
cliSockLen = sizeof(cliSock_in);
printf("\n Waiting for an incoming connection at port number %d", port);
int bytesread = 0;
for (;;)
{
//FD_ZERO(&allset);
rset = allset;
int nready = select(maxfd+1,&rset, NULL, NULL, NULL);
if(FD_ISSET(passiveSock, &rset)){
printf("In the first if");
connectedSock = accept(passiveSock, (struct sockaddr *)&cliSock_in, &cliSockLen);
/* if an error occurs while accepting */
if (connectedSock == -1) {
printf("\n Server: Accept error (errno = %d: %s)\n", errno, strerror(errno));
continue;
}
for (int i=0; i<MAX_CONNECTION; i++)
if (client[i].sd < 0){
client[i].sd=connectedSock;
strcpy(client[i].ipaddr, inet_ntoa(cliSock_in.sin_addr));
client[i].port= ntohs(cliSock_in.sin_port);
printf("\n Server: connection established with %s:%d\n",
client[i].ipaddr, client[i].port);
break;
}
FD_SET(connectedSock, &allset);
maxfd = max(maxfd, connectedSock);
}
else{
for(int j = 0 ; j < MAX_CONNECTION; j++){
connectedSock = client[j].sd;
printf("connectedSock is %d", connectedSock);
if(connectedSock < 0)
continue;
if(FD_ISSET(client[j].sd, &rset)){
unsigned char buffer[66000];
int index = 0;
bytesread = recv(connectedSock, (char *)buffer, 66000, 0);
int type;
type = (buffer[0] & 0xE0) >> 5;
if (type == 0)
{
char fname[100];
int i = 0;
int length = (buffer[i++] & 0x1F);
memcpy(&fname[0], &buffer[i], length);
fname[length] = '\0';
i += length;
int fs = 0;
fs += (buffer[i++] << 8) & 0xff00;
fs += buffer[i++];
char* filedata = (char*)malloc(fs*sizeof(char));
memcpy(&filedata[0], &buffer[i], fs);
filedata[fs] = '\0';
for (int i = 0; i < fs; i++)
printf("%c", filedata[i]);
printf("type=%d,length=%d,data=%s,fs=%d,filedata=%s", type, length, fname, fs, filedata);
std::ofstream of;
of.open(fname, std::ios::binary);
for (int i = 0; i < fs; i++)
of.write(filedata + i, 1);
of.close();
unsigned char rep;
int reptype = 0;
rep = (unsigned char)(reptype & 0x07);
send(connectedSock, (char*)(&rep), 1, 0);
}
else if (type == 1)
{
char fname[100];
int i = 0;
int length = (buffer[i++] & 0x1F);
memcpy(&fname[0], &buffer[i], length);
fname[length] = '\0';
i += length;
std::ifstream t;
int fs;
t.open(fname, std::ios::binary);
std::vector<char> vec((
std::istreambuf_iterator<char>(t)),
(std::istreambuf_iterator<char>()));// open input file
t.close();
fs = vec.size();
char* filedata = (char*)malloc(fs*sizeof(char)); // allocate memory for a buffer of appropriate dimension
filedata = &vec[0];
filedata[fs] = '\0';
i = 0;
unsigned char* repbuffer = (unsigned char*)malloc(3 + length + fs);
repbuffer[i] = (unsigned char)(type & 0x07);
repbuffer[i] = repbuffer[i] << 5;
repbuffer[i] = repbuffer[i] | (length & 0x0000003F);
i++;
memcpy(&repbuffer[i], fname, length);
i = i + length;
printf("sizeof fs=%d", sizeof(fs));
repbuffer[i++] = (unsigned char)((fs & 0xff00) >> 8);
repbuffer[i++] = (unsigned char)(fs & 0xff);
memcpy(&repbuffer[i], filedata, fs);
printf("sizeof buffer=%d", sizeof(repbuffer));
i = i + fs;
// printf("the buffer contains %s\n",&repbuffer[11]);
if (send(connectedSock, (char*)repbuffer, i, 0) == -1)
{
printf("A local error was detected while sending data! (errno = %d: %s)\n", errno, strerror(errno));
return -1;
}
}
else if (type == 2)
{
char fname[100],nfname[100];
int i = 0;
int length = (buffer[i++] & 0x1F);
memcpy(&fname[0], &buffer[i], length);
fname[length] = '\0';
i += length;
int nlength = (buffer[i++] & 0x1F);
memcpy(&nfname[0], &buffer[i], nlength);
nfname[nlength] = '\0';
rename(fname,nfname);
}
else if (type == 3)
{
char rep[32];
strcpy(rep, "bye change get help put");
int length = strlen(rep);
unsigned char* repbuffer = (unsigned char*)malloc(1 + length);
int type = 6;
repbuffer[0] = (unsigned char)(type & 0x07);
repbuffer[0] = repbuffer[0] << 5;
repbuffer[0] = repbuffer[0] | (length & 0x0000003F);
memcpy(&repbuffer[1], rep, length);
if (send(connectedSock, (char*)repbuffer, length+1, 0) == -1)
{
perror("A local error was detected while sending data!!");
return -1;
}
}
else if (type == 4)
{
closesocket(connectedSock);
}
break;
}
}
}
}
closesocket(passiveSock);
WSACleanup();
return 0;
}
I feel there's something wrong with the usage of FD_ISSET() method, I've been trying to figure out the error for 2 hours now, pleeassse help

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