[ovs-dev,v6] dpctl: Make opt_dpif_open() more general.

By making opt_dpif_open() more general, it can be used effectively
by all potential callers and avoids trying to open potentially bogus
datapaths provided by the user. Also, the error handling is improved by
having more specific errors.

Signed-off-by: Darrell Ball <dlu998@gmail.com>
---
 lib/dpctl.c             | 61 +++++++++++++++++++++++++++++++++++++++++++++----
 tests/system-traffic.at | 10 ++++----
 2 files changed, 61 insertions(+), 10 deletions(-)

hold off on this version

I can save a couple lines of code, so I'll send a V7

Darrell


On Wed, Aug 8, 2018 at 1:05 PM, Darrell Ball <dlu998@gmail.com> wrote:

> By making opt_dpif_open() more general, it can be used effectively
> by all potential callers and avoids trying to open potentially bogus
> datapaths provided by the user. Also, the error handling is improved by
> having more specific errors.
>
> Signed-off-by: Darrell Ball <dlu998@gmail.com>
> ---
>  lib/dpctl.c             | 61 ++++++++++++++++++++++++++++++
> +++++++++++++++----
>  tests/system-traffic.at | 10 ++++----
>  2 files changed, 61 insertions(+), 10 deletions(-)
>
> diff --git a/lib/dpctl.c b/lib/dpctl.c
> index c600eeb..6f50d89 100644
> --- a/lib/dpctl.c
> +++ b/lib/dpctl.c
> @@ -187,18 +187,69 @@ parsed_dpif_open(const char *arg_, bool create,
> struct dpif **dpifp)
>      return result;
>  }
>
> +static bool
> +dp_exists(const char *queried_dp)
> +{
> +    struct sset dpif_names = SSET_INITIALIZER(&dpif_names),
> +                dpif_types = SSET_INITIALIZER(&dpif_types);
> +    bool found = false;
> +    char *queried_name, *queried_type;
> +
> +    dp_parse_name(queried_dp, &queried_name, &queried_type);
> +    dp_enumerate_types(&dpif_types);
> +
> +    if (!sset_contains(&dpif_types, queried_type)) {
> +        goto out;
> +    }
> +
> +    int error = dp_enumerate_names(queried_type, &dpif_names);
> +    if (!error) {
> +        const char *name;
> +        SSET_FOR_EACH (name, &dpif_names) {
> +            if (!strcmp(name, queried_name)) {
> +                found = true;
> +                goto out;
> +            }
> +        }
> +    }
> +
> +out:
> +    sset_destroy(&dpif_names);
> +    sset_destroy(&dpif_types);
> +    return found;
> +}
> +
> +static bool
> +dp_arg_exists(int argc, const char *argv[])
> +{
> +    if (argc > 1 && dp_exists(argv[1])) {
> +        return true;
> +    }
> +    return false;
> +}
> +
>  /* Open a dpif with an optional name argument.
>   *
> - * The datapath name is not a mandatory parameter for this command.  If
> - * it is not specified -- so 'argc' < 'max_args' -- we retrieve it from
> - * the current setup, assuming only one exists.  On success stores the
> - * opened dpif in '*dpifp'. */
> + * The datapath name is not a mandatory parameter for this command.  If
> it is
> + * not specified, we retrieve it from the current setup, assuming only one
> + * exists.  On success stores the opened dpif in '*dpifp'. */
>  static int
>  opt_dpif_open(int argc, const char *argv[], struct dpctl_params *dpctl_p,
>                uint8_t max_args, struct dpif **dpifp)
>  {
> +    char *dpname;
> +    if (dp_arg_exists(argc, argv)) {
> +        dpname = xstrdup(argv[1]);
> +    } else if (argc != max_args) {
> +        dpname = get_one_dp(dpctl_p);
> +    } else {
> +        /* If the arguments are the maximum possible number and there is
> no
> +         * valid datapath argument, then we fall into the case of dpname
> is
> +         * NULL, since this is an error. */
> +        dpname = NULL;
> +    }
> +
>      int error = 0;
> -    char *dpname = argc >= max_args ? xstrdup(argv[1]) :
> get_one_dp(dpctl_p);
>      if (!dpname) {
>          error = EINVAL;
>          dpctl_error(dpctl_p, error, "datapath not found");
> diff --git a/tests/system-traffic.at b/tests/system-traffic.at
> index cbd9542..a7c8a24 100644
> --- a/tests/system-traffic.at
> +++ b/tests/system-traffic.at
> @@ -1040,7 +1040,7 @@ AT_CHECK([ovs-appctl dpctl/flush-conntrack zone=5
> $ICMP_TUPLE])
>  AT_CHECK([ovs-appctl dpctl/dump-conntrack | grep
> "orig=.src=10\.1\.1\.2,"], [1], [dnl
>  ])
>
> -OVS_TRAFFIC_VSWITCHD_STOP(["/could not create datapath/d"])
> +OVS_TRAFFIC_VSWITCHD_STOP
>  AT_CLEANUP
>
>  AT_SETUP([conntrack - IPv4 ping])
> @@ -1124,17 +1124,17 @@ ovs-appctl: ovs-vswitchd: server returned an error
>  ])
>
>  AT_CHECK([ovs-appctl dpctl/ct-set-maxconns one-bad-dp 10], [2], [], [dnl
> -ovs-vswitchd: opening datapath (Address family not supported by protocol)
> +ovs-vswitchd: datapath not found (Invalid argument)
>  ovs-appctl: ovs-vswitchd: server returned an error
>  ])
>
>  AT_CHECK([ovs-appctl dpctl/ct-get-maxconns one-bad-dp], [2], [], [dnl
> -ovs-vswitchd: opening datapath (Address family not supported by protocol)
> +ovs-vswitchd: datapath not found (Invalid argument)
>  ovs-appctl: ovs-vswitchd: server returned an error
>  ])
>
>  AT_CHECK([ovs-appctl dpctl/ct-get-nconns one-bad-dp], [2], [], [dnl
> -ovs-vswitchd: opening datapath (Address family not supported by protocol)
> +ovs-vswitchd: datapath not found (Invalid argument)
>  ovs-appctl: ovs-vswitchd: server returned an error
>  ])
>
> @@ -1164,7 +1164,7 @@ AT_CHECK([ovs-appctl dpctl/ct-get-maxconns], [], [dnl
>  10
>  ])
>
> -OVS_TRAFFIC_VSWITCHD_STOP(["/could not create datapath one-bad-dp of
> unknown type system/d"])
> +OVS_TRAFFIC_VSWITCHD_STOP
>  AT_CLEANUP
>
>  AT_SETUP([conntrack - IPv6 ping])
> --
> 1.9.1
>
>