From cc7f68045e5f3cfc6c932996af784ab319951426 Mon Sep 17 00:00:00 2001
From: Vladimir Oltean <vladimir.oltean@nxp.com>
Date: Tue, 19 Apr 2022 13:29:20 +0300
Subject: [PATCH 3/6] mreceive: support IPv6
Extend the mreceive program with a generalization of sockets,
addresses and socket options that covers both IPv4 and IPv6.
Most of the lower-level implementation is moved to common.c and exported
through common.h such that it can be reused by msend at a later time.
The makefile rule to link object files into executables is updated to
look at all specified objects rather than just the first, by using $^
instead of $<. Otherwise, common.o would be ignored when linking
mreceive.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
Makefile | 8 +-
common.c | 261 +++++++++++++++++++++++++++++++++++++++++++++++++++++
common.h | 36 ++++++++
mreceive.c | 142 ++++++++++-------------------
4 files changed, 349 insertions(+), 98 deletions(-)
create mode 100644 common.c
create mode 100644 common.h
--- a/Makefile
+++ b/Makefile
@@ -20,8 +20,8 @@ mandir = $(prefix)/share/man/man8
# ttcp is currently not part of the distribution because its not tested
# yet. Please test and let me know at GitHub so I can include it! :)
EXEC := msend mreceive
-OBJS := $(EXEC:=.o)
-DEPS := $(EXEC:=.d)
+OBJS := msend.o mreceive.o common.o
+DEPS := msend.d mreceive.d common.d
MANS = $(addsuffix .8,$(EXEC))
DISTFILES = README.md LICENSE.md
@@ -33,10 +33,10 @@ all: $(EXEC)
.o:
@printf " LINK $@\n"
- @$(CC) $(CFLAGS) $(LDFLAGS) -Wl,-Map,$@.map -o $@ $< $(LDLIBS$(LDLIBS-$(@)))
+ @$(CC) $(CFLAGS) $(LDFLAGS) -Wl,-Map,$@.map -o $@ $^ $(LDLIBS$(LDLIBS-$(@)))
msend: msend.o
-mreceive: mreceive.o
+mreceive: mreceive.o common.o
ttcp: ttcp.o
install: $(EXEC)
--- /dev/null
+++ b/common.c
@@ -0,0 +1,261 @@
+/*
+ * common.c -- Common functions for mreceive.c and msend.c
+ */
+#include <arpa/inet.h>
+#include <net/if.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "common.h"
+
+int ip_address_parse(const char *string, struct ip_address *ip)
+{
+ int ret;
+
+ ret = inet_pton(AF_INET6, string, &ip->addr6);
+ if (ret > 0) {
+ ip->family = AF_INET6;
+ } else {
+ ret = inet_pton(AF_INET, string, &ip->addr);
+ if (ret > 0) {
+ ip->family = AF_INET;
+ } else {
+ fprintf(stderr, "IP address %s not in known format\n",
+ string);
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+int socket_create(struct sock *s, int family, int port)
+{
+ struct sockaddr *serv_addr;
+ int sockopt = 1;
+ int fd, ret;
+
+ memset(s, 0, sizeof(*s));
+
+ if (family == AF_INET) {
+ serv_addr = (struct sockaddr *)&s->udp4;
+ s->udp4.sin_addr.s_addr = htonl(INADDR_ANY);
+ s->udp4.sin_port = htons(port);
+ s->udp4.sin_family = AF_INET;
+ s->addr_size = sizeof(struct sockaddr_in);
+ } else {
+ serv_addr = (struct sockaddr *)&s->udp6;
+ s->udp6.sin6_addr = in6addr_any;
+ s->udp6.sin6_port = htons(port);
+ s->udp6.sin6_family = AF_INET6;
+ s->addr_size = sizeof(struct sockaddr_in6);
+ }
+
+ fd = socket(family, SOCK_DGRAM, 0);
+ if (fd < 0) {
+ perror("socket");
+ return fd;
+ }
+
+ /* avoid EADDRINUSE error on bind() */
+ ret = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &sockopt, sizeof(int));
+ if (ret) {
+ perror("setsockopt() SO_REUSEADDR");
+ close(fd);
+ return ret;
+ }
+
+ ret = bind(fd, serv_addr, s->addr_size);
+ if (ret) {
+ perror("bind");
+ close(fd);
+ return ret;
+ }
+
+ s->fd = fd;
+
+ return 0;
+}
+
+static int igmp_join_by_saddr(struct sock *s, const struct ip_address *mc,
+ struct ip_address *saddr)
+{
+ struct ip_mreq mreq = {};
+ int fd = s->fd;
+ int off = 0;
+ int ret;
+
+ memcpy(&mreq.imr_multiaddr, &mc->addr, sizeof(struct in_addr));
+ memcpy(&mreq.imr_interface.s_addr, &saddr->addr,
+ sizeof(struct in_addr));
+
+ ret = setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq));
+ if (ret) {
+ perror("setsockopt() IP_ADD_MEMBERSHIP");
+ return -1;
+ }
+
+ ret = setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, &off, sizeof(int));
+ if (ret) {
+ perror("setsockopt() IP_MULTICAST_LOOP");
+ return -1;
+ }
+
+ return 0;
+}
+
+static int igmp_join_by_if_name(struct sock *s, const struct ip_address *mc,
+ const char *if_name)
+{
+ struct ip_mreqn mreq = {};
+ int fd = s->fd;
+ int if_index;
+ int off = 0;
+ int ret;
+
+ if_index = if_nametoindex(if_name);
+ if (!if_index) {
+ perror("if_nametoindex");
+ return -1;
+ }
+
+ memcpy(&mreq.imr_multiaddr, &mc->addr, sizeof(struct in_addr));
+ mreq.imr_ifindex = if_index;
+
+ ret = setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq));
+ if (ret) {
+ perror("setsockopt() IP_ADD_MEMBERSHIP");
+ return -1;
+ }
+
+ ret = setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, &off, sizeof(int));
+ if (ret) {
+ perror("setsockopt() IP_MULTICAST_LOOP");
+ return -1;
+ }
+
+ return 0;
+}
+
+static int mld_join(struct sock *s, const struct ip_address *mc,
+ const char *if_name)
+{
+ struct ipv6_mreq mreq = {};
+ int if_index, off = 0;
+ int fd = s->fd;
+ int ret;
+
+ if_index = if_nametoindex(if_name);
+ if (!if_index) {
+ perror("if_nametoindex");
+ return -1;
+ }
+
+ memcpy(&mreq.ipv6mr_multiaddr, &mc->addr6, sizeof(struct in6_addr));
+ mreq.ipv6mr_interface = if_index;
+ ret = setsockopt(fd, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &mreq,
+ sizeof(mreq));
+ if (ret) {
+ perror("setsockopt IPV6_ADD_MEMBERSHIP");
+ return -1;
+ }
+
+ ret = setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &off,
+ sizeof(int));
+ if (ret) {
+ perror("setsockopt IPV6_MULTICAST_LOOP");
+ return -1;
+ }
+
+ return 0;
+}
+
+int mc_join(struct sock *s, const struct ip_address *mc, const char *if_name,
+ int num_saddrs, struct ip_address *saddrs)
+{
+ int i, ret;
+
+ if (if_name) {
+ switch (mc->family) {
+ case AF_INET:
+ return igmp_join_by_if_name(s, mc, if_name);
+ case AF_INET6:
+ return mld_join(s, mc, if_name);
+ default:
+ return -1;
+ }
+ }
+
+ if (!num_saddrs) { /* single interface */
+ struct ip_address saddr = {
+ .family = AF_INET,
+ .addr.s_addr = INADDR_ANY,
+ };
+
+ return igmp_join_by_saddr(s, mc, &saddr);
+ }
+
+ for (i = 0; i < num_saddrs; i++) {
+ ret = igmp_join_by_saddr(s, mc, &saddrs[i]);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int igmp_set_ttl(int fd, int ttl)
+{
+ int ret;
+
+ ret = setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(int));
+ if (ret)
+ perror("setsockopt() IP_MULTICAST_TTL");
+
+ return ret;
+}
+
+static int mld_set_hop_limit(int fd, int limit)
+{
+ int ret;
+
+ ret = setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &limit,
+ sizeof(int));
+ if (ret)
+ perror("setsockopt() IPV6_MULTICAST_HOPS");
+
+ return ret;
+}
+
+int mc_set_hop_limit(struct sock *s, int limit)
+{
+ switch (s->addr_size) {
+ case sizeof(struct sockaddr_in):
+ return igmp_set_ttl(s->fd, limit);
+ case sizeof(struct sockaddr_in6):
+ return mld_set_hop_limit(s->fd, limit);
+ default:
+ return -1;
+ }
+}
+
+int mc_recv(struct sock *s, void *buf, size_t len, struct sock *from)
+{
+ from->addr_size = sizeof(struct sockaddr_in6);
+
+ return recvfrom(s->fd, buf, len, 0, (struct sockaddr *)&(from->udp6),
+ &from->addr_size);
+}
+
+int socket_get_port(const struct sock *s)
+{
+ switch (s->addr_size) {
+ case sizeof(struct sockaddr_in):
+ return ntohs(s->udp4.sin_port);
+ case sizeof(struct sockaddr_in6):
+ return ntohs(s->udp6.sin6_port);
+ default:
+ return 0;
+ }
+}
--- /dev/null
+++ b/common.h
@@ -0,0 +1,36 @@
+/*
+ * common.h -- Common header for mreceive.c and msend.c
+ */
+#ifndef _COMMON_H
+#define _COMMON_H
+
+#include <netinet/in.h>
+#include <netinet/ip.h>
+#include <netinet/ip6.h>
+
+struct ip_address {
+ int family;
+ union {
+ struct in_addr addr;
+ struct in6_addr addr6;
+ };
+};
+
+struct sock {
+ socklen_t addr_size;
+ union {
+ struct sockaddr_in udp4;
+ struct sockaddr_in6 udp6;
+ };
+ int fd;
+};
+
+int ip_address_parse(const char *string, struct ip_address *ip);
+int socket_create(struct sock *s, int family, int port);
+int mc_join(struct sock *s, const struct ip_address *mc, const char *if_name,
+ int num_saddrs, struct ip_address *saddrs);
+int mc_set_hop_limit(struct sock *s, int limit);
+int mc_recv(struct sock *s, void *buf, size_t len, struct sock *from);
+int socket_get_port(const struct sock *s);
+
+#endif
--- a/mreceive.c
+++ b/mreceive.c
@@ -28,6 +28,8 @@
#include <arpa/inet.h>
#include <sys/time.h>
+#include "common.h"
+
#define TRUE 1
#define FALSE 0
#ifndef INVALID_SOCKET
@@ -43,7 +45,7 @@
char *TEST_ADDR = "224.1.1.1";
int TEST_PORT = 4444;
-unsigned long IP[MAXIP];
+struct ip_address IP[MAXIP];
int NUM = 0;
void printHelp(void)
@@ -62,52 +64,12 @@ Usage: mreceive [-g GROUP] [-p PORT] [-i
-h Print the command usage.\n\n", VERSION);
}
-static void igmp_join_by_saddr(int s, in_addr_t multiaddr, in_addr_t interface)
-{
- struct ip_mreq mreq;
- int ret;
-
- mreq.imr_multiaddr.s_addr = multiaddr;
- mreq.imr_interface.s_addr = interface;
-
- ret = setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP,
- (char *)&mreq, sizeof(mreq));
- if (ret == SOCKET_ERROR) {
- printf("setsockopt() IP_ADD_MEMBERSHIP failed.\n");
- exit(1);
- }
-}
-
-static void igmp_join_by_if_name(int s, in_addr_t multicast,
- const char *if_name)
-{
- struct ip_mreqn mreq = {};
- int if_index;
- int ret;
-
- if_index = if_nametoindex(if_name);
- if (!if_index) {
- perror("if_nametoindex");
- exit(1);
- }
-
- mreq.imr_multiaddr.s_addr = multicast;
- mreq.imr_ifindex = if_index;
-
- ret = setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq));
- if (ret) {
- perror("setsockopt() IP_ADD_MEMBERSHIP");
- exit(1);
- }
-}
-
int main(int argc, char *argv[])
{
- struct sockaddr_in stLocal, stFrom;
unsigned char achIn[BUFSIZE];
- const char *if_name;
- int s, i;
- int iTmp, iRet;
+ const char *if_name = NULL;
+ struct ip_address mc;
+ struct sock s, from;
int ipnum = 0;
int ii;
unsigned int numreceived;
@@ -116,6 +78,8 @@ int main(int argc, char *argv[])
int starttime;
int curtime;
struct timeval tv;
+ int ret;
+ int i;
/*
if( argc < 2 ) {
@@ -152,7 +116,10 @@ int main(int argc, char *argv[])
} else if (strcmp(argv[ii], "-i") == 0) {
ii++;
if ((ii < argc) && !(strchr(argv[ii], '-'))) {
- IP[ipnum] = inet_addr(argv[ii]);
+ ret = ip_address_parse(argv[ii], &IP[ipnum]);
+ if (ret)
+ exit(1);
+
ii++;
ipnum++;
}
@@ -177,73 +144,59 @@ int main(int argc, char *argv[])
}
}
- /* get a datagram socket */
- s = socket(AF_INET, SOCK_DGRAM, 0);
- if (s == INVALID_SOCKET) {
- printf("socket() failed.\n");
+ ret = ip_address_parse(TEST_ADDR, &mc);
+ if (ret)
exit(1);
- }
- /* avoid EADDRINUSE error on bind() */
- iTmp = TRUE;
- iRet = setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (char *)&iTmp, sizeof(iTmp));
- if (iRet == SOCKET_ERROR) {
- printf("setsockopt() SO_REUSEADDR failed.\n");
+ if (mc.family == AF_INET6 && ipnum) {
+ printf("Joining IPv6 groups by source address not supported, use -I\n");
exit(1);
}
- /* name the socket */
- stLocal.sin_family = AF_INET;
- stLocal.sin_addr.s_addr = htonl(INADDR_ANY);
- stLocal.sin_port = htons(TEST_PORT);
- iRet = bind(s, (struct sockaddr *)&stLocal, sizeof(stLocal));
- if (iRet == SOCKET_ERROR) {
- printf("bind() failed.\n");
+ if (mc.family == AF_INET6 && !if_name) {
+ printf("-I is mandatory with IPv6\n");
exit(1);
}
- /* join the multicast group. */
- if (if_name) {
- igmp_join_by_if_name(s, inet_addr(TEST_ADDR), if_name);
- } else {
- if (!ipnum) { /* single interface */
- igmp_join_by_saddr(s, inet_addr(TEST_ADDR), INADDR_ANY);
- } else {
- for (i = 0; i < ipnum; i++) {
- igmp_join_by_saddr(s, inet_addr(TEST_ADDR),
- IP[i]);
- }
- }
- }
+ /* get a datagram socket */
+ ret = socket_create(&s, mc.family, TEST_PORT);
+ if (ret)
+ exit(1);
- /* set TTL to traverse up to multiple routers */
- iTmp = TTL_VALUE;
- iRet = setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL, (char *)&iTmp, sizeof(iTmp));
- if (iRet == SOCKET_ERROR) {
- printf("setsockopt() IP_MULTICAST_TTL failed.\n");
+ /* join the multicast group. */
+ ret = mc_join(&s, &mc, if_name, ipnum, IP);
+ if (ret)
exit(1);
- }
- /* disable loopback */
- /* iTmp = TRUE; */
- iTmp = FALSE;
- iRet = setsockopt(s, IPPROTO_IP, IP_MULTICAST_LOOP, (char *)&iTmp, sizeof(iTmp));
- if (iRet == SOCKET_ERROR) {
- printf("setsockopt() IP_MULTICAST_LOOP failed.\n");
+ /* set TTL to traverse up to multiple routers */
+ ret = mc_set_hop_limit(&s, TTL_VALUE);
+ if (ret)
exit(1);
- }
printf("Now receiving from multicast group: %s\n", TEST_ADDR);
for (i = 0;; i++) {
- socklen_t addr_size = sizeof(struct sockaddr_in);
+ char from_buf[INET6_ADDRSTRLEN];
static int iCounter = 1;
+ const char *addr_str;
/* receive from the multicast address */
- iRet = recvfrom(s, achIn, BUFSIZE, 0, (struct sockaddr *)&stFrom, &addr_size);
- if (iRet < 0) {
- printf("recvfrom() failed.\n");
+ ret = mc_recv(&s, achIn, BUFSIZE, &from);
+ if (ret < 0) {
+ perror("recvfrom");
+ exit(1);
+ }
+
+ if (mc.family == AF_INET) {
+ addr_str = inet_ntop(AF_INET, &from.udp4.sin_addr,
+ from_buf, INET6_ADDRSTRLEN);
+ } else {
+ addr_str = inet_ntop(AF_INET6, &from.udp6.sin6_addr,
+ from_buf, INET6_ADDRSTRLEN);
+ }
+ if (!addr_str) {
+ perror("inet_ntop");
exit(1);
}
@@ -256,7 +209,8 @@ int main(int argc, char *argv[])
numreceived =
(unsigned int)achIn[0] + ((unsigned int)(achIn[1]) << 8) + ((unsigned int)(achIn[2]) << 16) +
((unsigned int)(achIn[3]) >> 24);
- fprintf(stdout, "%5d\t%s:%5d\t%d.%03d\t%5d\n", iCounter, inet_ntoa(stFrom.sin_addr), ntohs(stFrom.sin_port),
+ fprintf(stdout, "%5d\t%s:%5d\t%d.%03d\t%5d\n", iCounter,
+ from_buf, socket_get_port(&from),
curtime / 1000000, (curtime % 1000000) / 1000, numreceived);
fflush(stdout);
rcvCountNew = numreceived;
@@ -276,7 +230,7 @@ int main(int argc, char *argv[])
rcvCountOld = rcvCountNew;
} else {
printf("Receive msg %d from %s:%d: %s\n",
- iCounter, inet_ntoa(stFrom.sin_addr), ntohs(stFrom.sin_port), achIn);
+ iCounter, from_buf, socket_get_port(&from), achIn);
}
iCounter++;
}