modem-helpers,sim: auto-detect if ICCID response is character swapped

This patch modifies mm_3gpp_parse_iccid() to auto-detect if an ICCID
response is character swapped or not by comparsing the major industry
identifier part of the ICCID response to the known value (89) for
telecommunication purposes. This addresses the issue where the same AT
command (e.g. AT^ICCID used by the huawei plugin) does not report ICCID
in a consistent format.

1 files changed, 18 insertions, 1 deletions

diff --git a/src/mm-modem-helpers.c b/src/mm-modem-helpers.c
index cf80f07b..9c86ebc2 100644
--- a/src/mm-modem-helpers.c
+++ b/src/mm-modem-helpers.c
@@ -1892,8 +1892,9 @@ mm_3gpp_get_ip_family_from_pdp_type (const gchar *pdp_type)
 /*************************************************************************/
 
 char *
-mm_3gpp_parse_iccid (const char *raw_iccid, gboolean swap, GError **error)
+mm_3gpp_parse_iccid (const char *raw_iccid, GError **error)
 {
+    gboolean swap;
     char *buf, *swapped = NULL;
     gsize len = 0;
     int f_pos = -1, i;
@@ -1934,6 +1935,22 @@ mm_3gpp_parse_iccid (const char *raw_iccid, gboolean swap, GError **error)
         goto error;
     }
 
+    /* The leading two digits of an ICCID is the major industry identifier and
+     * should be '89' for telecommunication purposes according to ISO/IEC 7812.
+     */
+    if (buf[0] == '8' && buf[1] == '9') {
+      swap = FALSE;
+    } else if (buf[0] == '9' && buf[1] == '8') {
+      swap = TRUE;
+    } else {
+      /* FIXME: Instead of erroring out, revisit this solution if we find any SIM
+       * that doesn't use '89' as the major industry identifier of the ICCID.
+       */
+      g_set_error (error, MM_CORE_ERROR, MM_CORE_ERROR_FAILED,
+                   "Invalid ICCID response (leading two digits are not 89)");
+      goto error;
+    }
+
     /* Ensure if there's an 'F' that it's second-to-last if swap = TRUE,
      * otherwise last if swap = FALSE */
     if (f_pos >= 0) {