I played a bit with inet sockets and cryo. With few modifications I 
managed to "checkpoint-restart" programs that use UDP sockets to listen
and send data.

This patch improves socket checkpointing in cryo:
* Save/restore socket family: we can checkpoint IPv6 sockets now.
* Save/restore socket type: we can checkpoint UDP sockets too.

Changelog:
----------
* V2:
    - Add helper issockbound() to improve readability of getsockinfo() 
    - Cleaned up a bunch of unneeded casts in getsockinfo()
    - Move socket binding code from restore_sock() to bind_sock()
* V1:
    - Initial version

Simple test programs for UDP sockets available upon request :)

Regards,
Benjamin

Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
---
 cr.c |   93 ++++++++++++++++++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 73 insertions(+), 20 deletions(-)

Index: cryodev/cr.c
===================================================================
--- cryodev.orig/cr.c
+++ cryodev/cr.c
@@ -67,11 +67,15 @@ int pagesize = 0;
 
 typedef struct isockinfo_t {
 	int fdnum;
-	int type;			/* socket type: UDP, TCP */
+	int type;			/* socket type: SOCK_STREAM, SOCK_DGRAM */
+	int family;			/* socket family: AF_INET, AF_INET6 */
 	int mode;			/* bind, listen, connect */
 	int opt;			/* various sockopt */
 	int backlog;			/* for listen(2) */
-	struct sockaddr_in locaddr;	/* for bind(2) */
+	union {
+		struct sockaddr_in  saddr4;
+		struct sockaddr_in6 saddr6;
+	} locaddr;			/* for bind(2) */
 	char tcpstate[TPI_LEN];
 } isockinfo_t;
 
@@ -177,9 +181,25 @@ int getmaps(pid_t pid, memseg_t **p)
 	return nseg;
 }
 
+static int issockbound(struct sockaddr *sa)
+{
+	if (sa->sa_family == AF_INET) {
+		struct sockaddr_in *sin = (struct sockaddr_in *) sa;
+		if (sin->sin_addr.s_addr != INADDR_ANY ||
+		    sin->sin_port != 0)
+			return 1;
+	} else if (sa->sa_family == AF_INET6) {
+		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) sa;
+		if (memcmp(&sin6->sin6_addr, &in6addr_any, 16) != 0 ||
+		    sin6->sin6_port != 0)
+			return 1;
+	}
+	return 0;
+}
+
 int getsockinfo(pid_t pid, pinfo_t *pi, int num)
 {
-	struct sockaddr name;
+	struct sockaddr_storage name;
 	int namelen = (int)sizeof(name), ret = 0;
 	int tpi_len = TPI_LEN;
 	int flag, flaglen;
@@ -188,35 +208,46 @@ int getsockinfo(pid_t pid, pinfo_t *pi, 
 	/* get socketname and see if it is an unix or an inet socket */
 	memset(&name, 0, sizeof(name));
 	PT_GETSOCKNAME(pid, num, &name, &namelen);
-	t_d(name.sa_family);
+	t_d(name.ss_family);
 
-	if (name.sa_family != (sa_family_t)AF_INET) return ret;
+	if (name.ss_family != (sa_family_t)AF_INET &&
+	    name.ss_family != (sa_family_t)AF_INET6)
+		return ret;
 		
 	if (! (pi->si = (isockinfo_t *)realloc(pi->si, sizeof(isockinfo_t) * (pi->ns+1)))) return -1;
 	psi = &pi->si[pi->ns];
-	memset((void *)psi, 0, sizeof(*psi));
+	memset(psi, 0, sizeof(*psi));
 
 	//pi->si[pi->ns].fdnum = num;
 	psi->fdnum = num;
+	psi->family = name.ss_family;
 
 	psi->mode = ISOCK_UNKNOWN;
-	memcpy((void *)&psi->locaddr, (void *)&name, sizeof(name));
-	if (psi->locaddr.sin_addr.s_addr != 0 || psi->locaddr.sin_port != 0) psi->mode |= ISOCK_BIND;
-	
+	memcpy(&psi->locaddr, &name, namelen);
+
+	if (issockbound((struct sockaddr *)&psi->locaddr))
+		psi->mode |= ISOCK_BIND;
+
+	flag = 0;
+	flaglen = sizeof(flag);
+	PT_GETSOCKOPT(pid, num, SOL_SOCKET, SO_TYPE, &flag, &flaglen);
+	if (flag)
+		psi->type = flag;
+
 	flag = 0;
-	flaglen = (int)sizeof(flag);
+	flaglen = sizeof(flag);
 	PT_GETSOCKOPT(pid, num, SOL_SOCKET, SO_REUSEADDR, &flag, &flaglen);
 	if (flag) psi->opt |= ISOCK_REUSEADDR; 
 
 	flag = 0;
-	flaglen = (int)sizeof(flag);
+	flaglen = sizeof(flag);
 	PT_GETSOCKOPT(pid, num, SOL_SOCKET, SO_ACCEPTCONN, &flag, &flaglen);
 	if (flag) {
 		psi->mode |= ISOCK_LISTEN;
 		//t_d(PT_GETSOCKOPT(pid, num, SOL_TCP, TPI_INFO, &tpi_info, &tpi_info_len));
 	}
 
-	namelen = (int)sizeof(name);
+	namelen = sizeof(name);
 	if (PT_GETPEERNAME(pid, num, &name, &namelen) == 0) {
 		t_d(psi->mode |= ISOCK_CONNECT);
 		t_d(PT_GETSOCKOPT(pid, num, SOL_TCP, TPI_TCP_STATE, pi->si[pi->ns].tcpstate, &tpi_len));
@@ -859,6 +890,31 @@ error:
 	return -1;
 }
 
+static void bind_sock(pid_t pid, isockinfo_t *isockinfo)
+{
+	int len;
+	struct sockaddr *sa;
+	struct sockaddr_in sin;
+	struct sockaddr_in6 sin6;
+
+	if (isockinfo->family == AF_INET) {
+		len = sizeof(sin);
+		memcpy(&sin, &isockinfo->locaddr.saddr4, len);
+		if (isockinfo->mode & ISOCK_CONNECT)
+			sin6.sin6_port = htons(0);
+		sa = (struct sockaddr *) &sin;
+	} else if (isockinfo->family == AF_INET6) {
+		len = sizeof(sin6);
+		memcpy(&sin6, &isockinfo->locaddr.saddr6, len);
+		if (isockinfo->mode & ISOCK_CONNECT)
+			sin.sin_port = htons(0);
+		sa = (struct sockaddr *) &sin6;
+	} else
+		ERROR("Unsupported socket family: %d\n",
+		      isockinfo->family);
+	t_d(PT_BIND(pid, isockinfo->fdnum, sa, len));
+}
+
 int restore_sock(int fd, pid_t pid)
 {
 	char item[64];
@@ -873,21 +929,18 @@ int restore_sock(int fd, pid_t pid)
 		else ITEM_SET(isockinfo, isockinfo_t);
 		else break;	// unknown item
 
-		t_d(sock = PT_SOCKET(pid, AF_INET, SOCK_STREAM, 0));
+		t_d(sock = PT_SOCKET(pid, isockinfo->family, isockinfo->type, 0));
 		if (sock < 0) {
 			ERROR("PT_SOCKET(%d, %d, %d, %d) errno=%d: %s",
-				pid, AF_INET, SOCK_STREAM, 0, sock, strerror(-sock)); 
+			      pid, isockinfo->family, isockinfo->type, 0,
+			      sock, strerror(-sock));
 		}
 		t_d(PT_DUP2(pid, sock, isockinfo->fdnum));
 		if (sock != isockinfo->fdnum) t_d(PT_CLOSE(pid, sock));
 		
-		if (isockinfo->mode & ISOCK_BIND) {
-			struct sockaddr_in sin;
+		if (isockinfo->mode & ISOCK_BIND)
+			bind_sock(pid, isockinfo);
 
-			memcpy((void *)&sin, (void *)&isockinfo->locaddr, sizeof(sin));
-			if (isockinfo->mode & ISOCK_CONNECT) sin.sin_port = htons(0);
-			t_d(PT_BIND(pid, isockinfo->fdnum, &sin, sizeof(sin)));
-		}
 		if (isockinfo->mode & ISOCK_LISTEN) {
 			t_d(PT_LISTEN(pid, isockinfo->fdnum, 64));	//FIXME: get backlog from TPI_INFO
 		}

-- 
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Quoting Benjamin Thery (benjamin.thery@bull.net):
> I played a bit with inet sockets and cryo. With few modifications I 
> managed to "checkpoint-restart" programs that use UDP sockets to listen
> and send data.
> 
> This patch improves socket checkpointing in cryo:
> * Save/restore socket family: we can checkpoint IPv6 sockets now.
> * Save/restore socket type: we can checkpoint UDP sockets too.
> 
> Changelog:
> ----------
> * V2:
>     - Add helper issockbound() to improve readability of getsockinfo() 
>     - Cleaned up a bunch of unneeded casts in getsockinfo()
>     - Move socket binding code from restore_sock() to bind_sock()
> * V1:
>     - Initial version
> 
> Simple test programs for UDP sockets available upon request :)
> 
> Regards,
> Benjamin
> 
> Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>

Applied, thanks.

Please do send the test programs, and I'll add them under cryo/tests.

-serge

> ---
>  cr.c |   93 ++++++++++++++++++++++++++++++++++++++++++++++++++++---------------
>  1 file changed, 73 insertions(+), 20 deletions(-)
> 
> Index: cryodev/cr.c
> ===================================================================
> --- cryodev.orig/cr.c
> +++ cryodev/cr.c
> @@ -67,11 +67,15 @@ int pagesize = 0;
> 
>  typedef struct isockinfo_t {
>  	int fdnum;
> -	int type;			/* socket type: UDP, TCP */
> +	int type;			/* socket type: SOCK_STREAM, SOCK_DGRAM */
> +	int family;			/* socket family: AF_INET, AF_INET6 */
>  	int mode;			/* bind, listen, connect */
>  	int opt;			/* various sockopt */
>  	int backlog;			/* for listen(2) */
> -	struct sockaddr_in locaddr;	/* for bind(2) */
> +	union {
> +		struct sockaddr_in  saddr4;
> +		struct sockaddr_in6 saddr6;
> +	} locaddr;			/* for bind(2) */
>  	char tcpstate[TPI_LEN];
>  } isockinfo_t;
> 
> @@ -177,9 +181,25 @@ int getmaps(pid_t pid, memseg_t **p)
>  	return nseg;
>  }
> 
> +static int issockbound(struct sockaddr *sa)
> +{
> +	if (sa->sa_family == AF_INET) {
> +		struct sockaddr_in *sin = (struct sockaddr_in *) sa;
> +		if (sin->sin_addr.s_addr != INADDR_ANY ||
> +		    sin->sin_port != 0)
> +			return 1;
> +	} else if (sa->sa_family == AF_INET6) {
> +		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) sa;
> +		if (memcmp(&sin6->sin6_addr, &in6addr_any, 16) != 0 ||
> +		    sin6->sin6_port != 0)
> +			return 1;
> +	}
> +	return 0;
> +}
> +
>  int getsockinfo(pid_t pid, pinfo_t *pi, int num)
>  {
> -	struct sockaddr name;
> +	struct sockaddr_storage name;
>  	int namelen = (int)sizeof(name), ret = 0;
>  	int tpi_len = TPI_LEN;
>  	int flag, flaglen;
> @@ -188,35 +208,46 @@ int getsockinfo(pid_t pid, pinfo_t *pi, 
>  	/* get socketname and see if it is an unix or an inet socket */
>  	memset(&name, 0, sizeof(name));
>  	PT_GETSOCKNAME(pid, num, &name, &namelen);
> -	t_d(name.sa_family);
> +	t_d(name.ss_family);
> 
> -	if (name.sa_family != (sa_family_t)AF_INET) return ret;
> +	if (name.ss_family != (sa_family_t)AF_INET &&
> +	    name.ss_family != (sa_family_t)AF_INET6)
> +		return ret;
>  		
>  	if (! (pi->si = (isockinfo_t *)realloc(pi->si, sizeof(isockinfo_t) * (pi->ns+1)))) return -1;
>  	psi = &pi->si[pi->ns];
> -	memset((void *)psi, 0, sizeof(*psi));
> +	memset(psi, 0, sizeof(*psi));
> 
>  	//pi->si[pi->ns].fdnum = num;
>  	psi->fdnum = num;
> +	psi->family = name.ss_family;
> 
>  	psi->mode = ISOCK_UNKNOWN;
> -	memcpy((void *)&psi->locaddr, (void *)&name, sizeof(name));
> -	if (psi->locaddr.sin_addr.s_addr != 0 || psi->locaddr.sin_port != 0) psi->mode |= ISOCK_BIND;
> -	
> +	memcpy(&psi->locaddr, &name, namelen);
> +
> +	if (issockbound((struct sockaddr *)&psi->locaddr))
> +		psi->mode |= ISOCK_BIND;
> +
> +	flag = 0;
> +	flaglen = sizeof(flag);
> +	PT_GETSOCKOPT(pid, num, SOL_SOCKET, SO_TYPE, &flag, &flaglen);
> +	if (flag)
> +		psi->type = flag;
> +
>  	flag = 0;
> -	flaglen = (int)sizeof(flag);
> +	flaglen = sizeof(flag);
>  	PT_GETSOCKOPT(pid, num, SOL_SOCKET, SO_REUSEADDR, &flag, &flaglen);
>  	if (flag) psi->opt |= ISOCK_REUSEADDR; 
> 
>  	flag = 0;
> -	flaglen = (int)sizeof(flag);
> +	flaglen = sizeof(flag);
>  	PT_GETSOCKOPT(pid, num, SOL_SOCKET, SO_ACCEPTCONN, &flag, &flaglen);
>  	if (flag) {
>  		psi->mode |= ISOCK_LISTEN;
>  		//t_d(PT_GETSOCKOPT(pid, num, SOL_TCP, TPI_INFO, &tpi_info, &tpi_info_len));
>  	}
> 
> -	namelen = (int)sizeof(name);
> +	namelen = sizeof(name);
>  	if (PT_GETPEERNAME(pid, num, &name, &namelen) == 0) {
>  		t_d(psi->mode |= ISOCK_CONNECT);
>  		t_d(PT_GETSOCKOPT(pid, num, SOL_TCP, TPI_TCP_STATE, pi->si[pi->ns].tcpstate, &tpi_len));
> @@ -859,6 +890,31 @@ error:
>  	return -1;
>  }
> 
> +static void bind_sock(pid_t pid, isockinfo_t *isockinfo)
> +{
> +	int len;
> +	struct sockaddr *sa;
> +	struct sockaddr_in sin;
> +	struct sockaddr_in6 sin6;
> +
> +	if (isockinfo->family == AF_INET) {
> +		len = sizeof(sin);
> +		memcpy(&sin, &isockinfo->locaddr.saddr4, len);
> +		if (isockinfo->mode & ISOCK_CONNECT)
> +			sin6.sin6_port = htons(0);
> +		sa = (struct sockaddr *) &sin;
> +	} else if (isockinfo->family == AF_INET6) {
> +		len = sizeof(sin6);
> +		memcpy(&sin6, &isockinfo->locaddr.saddr6, len);
> +		if (isockinfo->mode & ISOCK_CONNECT)
> +			sin.sin_port = htons(0);
> +		sa = (struct sockaddr *) &sin6;
> +	} else
> +		ERROR("Unsupported socket family: %d\n",
> +		      isockinfo->family);
> +	t_d(PT_BIND(pid, isockinfo->fdnum, sa, len));
> +}
> +
>  int restore_sock(int fd, pid_t pid)
>  {
>  	char item[64];
> @@ -873,21 +929,18 @@ int restore_sock(int fd, pid_t pid)
>  		else ITEM_SET(isockinfo, isockinfo_t);
>  		else break;	// unknown item
> 
> -		t_d(sock = PT_SOCKET(pid, AF_INET, SOCK_STREAM, 0));
> +		t_d(sock = PT_SOCKET(pid, isockinfo->family, isockinfo->type, 0));
>  		if (sock < 0) {
>  			ERROR("PT_SOCKET(%d, %d, %d, %d) errno=%d: %s",
> -				pid, AF_INET, SOCK_STREAM, 0, sock, strerror(-sock)); 
> +			      pid, isockinfo->family, isockinfo->type, 0,
> +			      sock, strerror(-sock));
>  		}
>  		t_d(PT_DUP2(pid, sock, isockinfo->fdnum));
>  		if (sock != isockinfo->fdnum) t_d(PT_CLOSE(pid, sock));
>  		
> -		if (isockinfo->mode & ISOCK_BIND) {
> -			struct sockaddr_in sin;
> +		if (isockinfo->mode & ISOCK_BIND)
> +			bind_sock(pid, isockinfo);
> 
> -			memcpy((void *)&sin, (void *)&isockinfo->locaddr, sizeof(sin));
> -			if (isockinfo->mode & ISOCK_CONNECT) sin.sin_port = htons(0);
> -			t_d(PT_BIND(pid, isockinfo->fdnum, &sin, sizeof(sin)));
> -		}
>  		if (isockinfo->mode & ISOCK_LISTEN) {
>  			t_d(PT_LISTEN(pid, isockinfo->fdnum, 64));	//FIXME: get backlog from TPI_INFO
>  		}
> 
> -- 
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