[M] Change in osmo-bts[master]: paging: also accept IMSI strings shorter than 3

dexter has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmo-bts/+/33766 ) Change subject: paging: also accept IMSI strings shorter than 3 ...................................................................... paging: also accept IMSI strings shorter than 3 When an IMMEDIATE ASSIGNMENT MAC block (from PCUIF) is added to the paging queue, then also an IMSI is required. The paging queue uses the last three digits of the IMSI to calculate the paging group. In case no IMSI or an IMSI shorter than 3 digits is given, the MAC block is rejected. This was handeled differently before. Even an IMSI of length 0 would still be interpreted as "000" and not rejected. See also: I9f3799916e8102bf1ce0f21891f2d24f43091f01 Let's restore the behaviour we had before and accept short IMSI strings again. Change-Id: Iab1c3f1c39dd59bb53aa74b2c9e9e135e3985e0b Related: OS#6099 --- M src/common/paging.c 1 file changed, 47 insertions(+), 10 deletions(-) git pull ssh://gerrit.osmocom.org:29418/osmo-bts refs/changes/66/33766/1 diff --git a/src/common/paging.c b/src/common/paging.c index b1aad7c..ee1b201 100644 --- a/src/common/paging.c +++ b/src/common/paging.c @@ -270,6 +270,30 @@ return 0; } +/* Convert the last three digits of a given IMSI string to their decimal representation. In case the given IMSI string + * is shorter than three digits, the missing digits will be assumed to be 0. */ +static uint16_t convert_imsi_to_decimal(const char *imsi) +{ + uint16_t _imsi = 0; + size_t imsi_len = strlen(imsi); + + if (imsi_len >= 3) { + imsi = imsi + imsi_len - 3; + _imsi = 100 * ((*(imsi++)) - '0'); + _imsi += 10 * ((*(imsi++)) - '0'); + _imsi += (*(imsi++)) - '0'; + } else if (imsi_len == 2) { + imsi = imsi + imsi_len - 2; + _imsi += 10 * ((*(imsi++)) - '0'); + _imsi += (*(imsi++)) - '0'; + } else if (imsi_len == 1) { + imsi = imsi + imsi_len - 1; + _imsi += (*(imsi++)) - '0'; + } + + return _imsi; +} + /* Add a ready formatted MAC block message to the paging queue, this can be an IMMEDIATE ASSIGNMENT, or a * PAGING COMMAND (from the PCU) */ int paging_add_macblock(struct paging_state *ps, uint32_t tlli, const char *imsi, bool confirm, const uint8_t *macblock) @@ -278,7 +302,6 @@ struct paging_record *pr; uint16_t paging_group; uint16_t _imsi; - size_t imsi_len = strlen(imsi); check_congestion(ps); @@ -289,15 +312,7 @@ return -ENOSPC; } - /* Tha paging group is calculated from the last three digits of the IMSI */ - if (imsi_len < 3) { - LOGP(DPAG, LOGL_ERROR, "IMSI with invalid length %zu (expecting at least the last 3 digits)\n", imsi_len); - return -EINVAL; - } - imsi = imsi + imsi_len - 3; - _imsi = 100 * ((*(imsi++)) - '0'); - _imsi += 10 * ((*(imsi++)) - '0'); - _imsi += (*(imsi++)) - '0'; + _imsi = convert_imsi_to_decimal(imsi); paging_group = gsm0502_calc_paging_group(&ps->chan_desc, _imsi); group_q = &ps->paging_queue[paging_group]; -- To view, visit https://gerrit.osmocom.org/c/osmo-bts/+/33766 To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings Gerrit-Project: osmo-bts Gerrit-Branch: master Gerrit-Change-Id: Iab1c3f1c39dd59bb53aa74b2c9e9e135e3985e0b Gerrit-Change-Number: 33766 Gerrit-PatchSet: 1 Gerrit-Owner: dexter &lt;pmaier(a)sysmocom.de&gt; Gerrit-MessageType: newchange