Re: [Qemu-devel] [PATCH v3 For-1.6 1/7] rdma: bugfix: make IPv6 support work

[Orit Wasserman <owasserm@redhat.com>]

On 08/04/2013 05:54 AM, mrhines@linux.vnet.ibm.com wrote:
> From: "Michael R. Hines" <mrhines@us.ibm.com>
> 
> RDMA does not use sockets, so we cannot use many of the socket
> helper functions, but we *do* use inet_parse() which gives
> RDMA all the necessary details of the connection parameters.
> 
> However, when testing with libvirt, a simple IPv6 migration test failed
> because we were not using getaddrinfo() properly.
> 
> This makes IPv6 migration over RDMA work.
> 
> Signed-off-by: Michael R. Hines <mrhines@us.ibm.com>
> ---
>  migration-rdma.c |   33 +++++++++++++++++++++------------
>  1 file changed, 21 insertions(+), 12 deletions(-)
> 
> diff --git a/migration-rdma.c b/migration-rdma.c
> index d044830..9cf73e3 100644
> --- a/migration-rdma.c
> +++ b/migration-rdma.c
> @@ -392,6 +392,7 @@ typedef struct RDMAContext {
>      uint64_t unregistrations[RDMA_SIGNALED_SEND_MAX];
>  
>      GHashTable *blockmap;
> +    bool ipv6;
>  } RDMAContext;
>  
>  /*
> @@ -744,6 +745,7 @@ static int qemu_rdma_resolve_host(RDMAContext *rdma, Error **errp)
>      char port_str[16];
>      struct rdma_cm_event *cm_event;
>      char ip[40] = "unknown";
> +    int af = rdma->ipv6 ? PF_INET6 : PF_INET;
>  
>      if (rdma->host == NULL || !strcmp(rdma->host, "")) {
>          ERROR(errp, "RDMA hostname has not been set\n");
> @@ -773,7 +775,7 @@ static int qemu_rdma_resolve_host(RDMAContext *rdma, Error **errp)
>          goto err_resolve_get_addr;
>      }
>  
> -    inet_ntop(AF_INET, &((struct sockaddr_in *) res->ai_addr)->sin_addr,
> +    inet_ntop(af, &((struct sockaddr_in *) res->ai_addr)->sin_addr,
>                                  ip, sizeof ip);
>      DPRINTF("%s => %s\n", rdma->host, ip);
>  
> @@ -2236,9 +2238,12 @@ err_rdma_source_connect:
>  static int qemu_rdma_dest_init(RDMAContext *rdma, Error **errp)
>  {
>      int ret = -EINVAL, idx;
> +    int af = rdma->ipv6 ? PF_INET6 : PF_INET;
>      struct sockaddr_in sin;
>      struct rdma_cm_id *listen_id;
>      char ip[40] = "unknown";
> +    struct addrinfo *res;
> +    char port_str[16];
>  
>      for (idx = 0; idx <= RDMA_WRID_MAX; idx++) {
>          rdma->wr_data[idx].control_len = 0;
> @@ -2266,27 +2271,30 @@ static int qemu_rdma_dest_init(RDMAContext *rdma, Error **errp)
>      }
>  
>      memset(&sin, 0, sizeof(sin));
> -    sin.sin_family = AF_INET;
> +    sin.sin_family = af;
>      sin.sin_port = htons(rdma->port);
> +    snprintf(port_str, 16, "%d", rdma->port);
> +    port_str[15] = '\0';
>  
>      if (rdma->host && strcmp("", rdma->host)) {
> -        struct hostent *dest_addr;
> -        dest_addr = gethostbyname(rdma->host);
> -        if (!dest_addr) {
> -            ERROR(errp, "migration could not gethostbyname!\n");
> -            ret = -EINVAL;
> +        ret = getaddrinfo(rdma->host, port_str, NULL, &res);

Hi Michael,

getaddrinfo can return a list of addresses, you need to handle it.
Look at qemu-sockets.c for example.

Regards,
Orit
> +        if (ret < 0) {
> +            ERROR(errp, "could not getaddrinfo address %s\n", rdma->host);
>              goto err_dest_init_bind_addr;
>          }
> -        memcpy(&sin.sin_addr.s_addr, dest_addr->h_addr,
> -                dest_addr->h_length);
> -        inet_ntop(AF_INET, dest_addr->h_addr, ip, sizeof ip);
> +
> +
> +        inet_ntop(af, &((struct sockaddr_in *) res->ai_addr)->sin_addr,
> +                                    ip, sizeof ip);
>      } else {
> -        sin.sin_addr.s_addr = INADDR_ANY;
> +        ERROR(errp, "migration host and port not specified!\n");
> +        ret = -EINVAL;
> +        goto err_dest_init_bind_addr;
>      }
>  
>      DPRINTF("%s => %s\n", rdma->host, ip);
>  
> -    ret = rdma_bind_addr(listen_id, (struct sockaddr *)&sin);
> +    ret = rdma_bind_addr(listen_id, res->ai_addr);
>      if (ret) {
>          ERROR(errp, "Error: could not rdma_bind_addr!\n");
>          goto err_dest_init_bind_addr;
> @@ -2321,6 +2329,7 @@ static void *qemu_rdma_data_init(const char *host_port, Error **errp)
>          if (addr != NULL) {
>              rdma->port = atoi(addr->port);
>              rdma->host = g_strdup(addr->host);
> +            rdma->ipv6 = addr->ipv6;
>          } else {
>              ERROR(errp, "bad RDMA migration address '%s'", host_port);
>              g_free(rdma);
>