Re: [Qemu-devel] [PATCH for-1.6 4/4] rdma: proper getaddrinfo() handling

[Orit Wasserman <owasserm@redhat.com>]

On 08/07/2013 07:05 PM, mrhines@linux.vnet.ibm.com wrote:
> From: "Michael R. Hines" <mrhines@us.ibm.com>
> 
> getaddrinfo() already knows what it's doing,
> wqand can potentially return multiple addresses.
> 
> Signed-off-by: Michael R. Hines <mrhines@us.ibm.com>
> ---
>  migration-rdma.c |   56 ++++++++++++++++++++++++++++--------------------------
>  1 file changed, 29 insertions(+), 27 deletions(-)
> 
> diff --git a/migration-rdma.c b/migration-rdma.c
> index 30e08cd..d71cca5 100644
> --- a/migration-rdma.c
> +++ b/migration-rdma.c
> @@ -392,7 +392,6 @@ typedef struct RDMAContext {
>      uint64_t unregistrations[RDMA_SIGNALED_SEND_MAX];
>  
>      GHashTable *blockmap;
> -    bool ipv6;
>  } RDMAContext;
>  
>  /*
> @@ -745,7 +744,7 @@ 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;
> +    struct addrinfo *e;
>  
>      if (rdma->host == NULL || !strcmp(rdma->host, "")) {
>          ERROR(errp, "RDMA hostname has not been set");
> @@ -775,18 +774,23 @@ static int qemu_rdma_resolve_host(RDMAContext *rdma, Error **errp)
>          goto err_resolve_get_addr;
>      }
>  
> -    inet_ntop(af, &((struct sockaddr_in *) res->ai_addr)->sin_addr,
> -                                ip, sizeof ip);
> -    DPRINTF("%s => %s\n", rdma->host, ip);
> +    for (e = res; e != NULL; e = e->ai_next) {
> +        inet_ntop(e->ai_family,
> +            &((struct sockaddr_in *) e->ai_addr)->sin_addr, ip, sizeof ip);
> +        DPRINTF("Trying %s => %s\n", rdma->host, ip);
>  
> -    /* resolve the first address */
> -    ret = rdma_resolve_addr(rdma->cm_id, NULL, res->ai_addr,
> -            RDMA_RESOLVE_TIMEOUT_MS);
> -    if (ret) {
> -        ERROR(errp, "could not resolve address %s", rdma->host);
> -        goto err_resolve_get_addr;
> +        /* resolve the first address */
> +        ret = rdma_resolve_addr(rdma->cm_id, NULL, e->ai_addr,
> +                RDMA_RESOLVE_TIMEOUT_MS);
> +        if (!ret) {
> +            goto route;
> +        }
>      }
>  
> +    ERROR(errp, "could not resolve address %s", rdma->host);
> +    goto err_resolve_get_addr;
> +
> +route:
>      qemu_rdma_dump_gid("source_resolve_addr", rdma->cm_id);
>  
>      ret = rdma_get_cm_event(rdma->channel, &cm_event);
> @@ -2260,8 +2264,6 @@ 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;
> @@ -2292,35 +2294,36 @@ static int qemu_rdma_dest_init(RDMAContext *rdma, Error **errp)
>          goto err_dest_init_create_listen_id;
>      }
>  
> -    memset(&sin, 0, sizeof(sin));
> -    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 addrinfo *e;
> +
>          ret = getaddrinfo(rdma->host, port_str, NULL, &res);
>          if (ret < 0) {
>              ERROR(errp, "could not getaddrinfo address %s", rdma->host);
>              goto err_dest_init_bind_addr;
>          }
>  
> +        for (e = res; e != NULL; e = e->ai_next) {
> +            inet_ntop(e->ai_family,
> +                &((struct sockaddr_in *) e->ai_addr)->sin_addr, ip, sizeof ip);
> +            DPRINTF("Trying %s => %s\n", rdma->host, ip);
> +            ret = rdma_bind_addr(listen_id, e->ai_addr);
> +            if (!ret) {
> +                goto listen;
> +            }
> +        }
>  
> -        inet_ntop(af, &((struct sockaddr_in *) res->ai_addr)->sin_addr,
> -                                    ip, sizeof ip);
> +        ERROR(errp, "Error: could not rdma_bind_addr!");
> +        goto err_dest_init_bind_addr;
>      } else {
>          ERROR(errp, "migration host and port not specified!");
>          ret = -EINVAL;
>          goto err_dest_init_bind_addr;
>      }
> -
> -    DPRINTF("%s => %s\n", rdma->host, ip);
> -
> -    ret = rdma_bind_addr(listen_id, res->ai_addr);
> -    if (ret) {
> -        ERROR(errp, "Error: could not rdma_bind_addr!");
> -        goto err_dest_init_bind_addr;
> -    }
> +listen:
>  
>      rdma->listen_id = listen_id;
>      qemu_rdma_dump_gid("dest_init", listen_id);
> @@ -2351,7 +2354,6 @@ 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);
> 

Looks good,
Reviewed-by: Orit Wasserman <owasserm@redhat.com>