svn commit: r355430 - head/sys/cam/scsi

[Steven Hartland]

If the illegal chars where removed or replaced would the result be useful,
if so might that be a better approach?

On Fri, 6 Dec 2019 at 00:06, Alan Somers <asomers at freebsd.org> wrote:

> Author: asomers
> Date: Fri Dec  6 00:06:05 2019
> New Revision: 355430
> URL: https://svnweb.freebsd.org/changeset/base/355430
>
> Log:
>   ses: sanitize illegal strings in SES element descriptors
>
>   The SES4r3 standard requires that element descriptors may only contain
> ASCII
>   characters in the range 0x20 to 0x7e.  Some SuperMicro expanders violate
>   that rule.  This patch adds a sanity check to ses(4).  Descriptors in
>   violation will be replaced by "<invalid>".
>
>   This patch fixes "sesutil --libxo xml" on such systems.  Previously it
> would
>   generate non-well-formed XML output.
>
>   PR:           241929
>   Reviewed by:  allanjude
>   MFC after:    2 weeks
>   Sponsored by: Axcient
>
> Modified:
>   head/sys/cam/scsi/scsi_enc_ses.c
>
> Modified: head/sys/cam/scsi/scsi_enc_ses.c
>
> ==============================================================================
> --- head/sys/cam/scsi/scsi_enc_ses.c    Thu Dec  5 19:39:51 2019
> (r355429)
> +++ head/sys/cam/scsi/scsi_enc_ses.c    Fri Dec  6 00:06:05 2019
> (r355430)
> @@ -110,7 +110,7 @@ typedef struct ses_addl_status {
>  typedef struct ses_element {
>         uint8_t eip;                    /* eip bit is set */
>         uint16_t descr_len;             /* length of the descriptor */
> -       char *descr;                    /* descriptor for this object */
> +       const char *descr;              /* descriptor for this object */
>         struct ses_addl_status addl;    /* additional status info */
>  } ses_element_t;
>
> @@ -1977,6 +1977,35 @@ ses_publish_cache(enc_softc_t *enc, struct
> enc_fsm_sta
>         return (0);
>  }
>
> +/*
> + * \brief Sanitize an element descriptor
> + *
> + * The SES4r3 standard, sections 3.1.2 and 6.1.10, specifies that element
> + * descriptors may only contain ASCII characters in the range 0x20 to
> 0x7e.
> + * But some vendors violate that rule.  Ensure that we only expose
> compliant
> + * descriptors to userland.
> + *
> + * \param desc         SES element descriptor as reported by the hardware
> + * \param len          Length of desc in bytes, not necessarily including
> + *                     trailing NUL.  It will be modified if desc is
> invalid.
> + */
> +static const char*
> +ses_sanitize_elm_desc(const char *desc, uint16_t *len)
> +{
> +       const char *invalid = "<invalid>";
> +       int i;
> +
> +       for (i = 0; i < *len; i++) {
> +               if (desc[i] < 0x20 || desc[i] > 0x7e) {
> +                       *len = strlen(invalid);
> +                       return (invalid);
> +               } else if (desc[i] == 0) {
> +                       break;
> +               }
> +       }
> +       return (desc);
> +}
> +
>  /**
>   * \brief Parse the descriptors for each object.
>   *
> @@ -2061,7 +2090,8 @@ ses_process_elm_descs(enc_softc_t *enc, struct
> enc_fsm
>                 if (length > 0) {
>                         elmpriv = element->elm_private;
>                         elmpriv->descr_len = length;
> -                       elmpriv->descr = &buf[offset];
> +                       elmpriv->descr =
> ses_sanitize_elm_desc(&buf[offset],
> +                           &elmpriv->descr_len);
>                 }
>
>                 /* skip over the descriptor itself */
>