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

["Michael R. Hines" <mrhines@linux.vnet.ibm.com>]

On 08/08/2013 02:12 AM, Orit Wasserman wrote:
> 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>
>
>
Thanks.