diff options
| author | Harald Welte <laforge@gnumonks.org> | 2019-08-31 21:25:05 +0200 |
|---|---|---|
| committer | Harald Welte <laforge@gnumonks.org> | 2019-08-31 21:27:57 +0200 |
| commit | f2210030440d71a56940e02822532977609a1d05 (patch) | |
| tree | 21ddd946f75a23733970cb37914186708065d3ce | |
| parent | f89cbd0019393ed8aeefa8b633e330982c8ab126 (diff) | |
cbsp: Fix endless loop iteration when decoding cell list IEs
The CBSP code assumed that gsm0808_decode_cell_id_u() would return
the number of bytes it has consumed/parsed. But it actually always
returns '0', whcih makes us run in an endless loop :(
Change-Id: I5758af4ec11a827d4b888a3a16c4ec22de90a7d6
| -rw-r--r-- | include/osmocom/gsm/gsm0808_utils.h | 1 | ||||
| -rw-r--r-- | src/gsm/cbsp.c | 8 | ||||
| -rw-r--r-- | src/gsm/gsm0808_utils.c | 21 |
3 files changed, 26 insertions, 4 deletions
diff --git a/include/osmocom/gsm/gsm0808_utils.h b/include/osmocom/gsm/gsm0808_utils.h index 76db2b6d..ccdf5ed9 100644 --- a/include/osmocom/gsm/gsm0808_utils.h +++ b/include/osmocom/gsm/gsm0808_utils.h @@ -95,6 +95,7 @@ void gsm0808_cell_id_from_cgi(struct gsm0808_cell_id *cid, enum CELL_IDENT id_di int gsm0808_cell_id_to_cgi(struct osmo_cell_global_id *cgi, const struct gsm0808_cell_id *cid); void gsm0808_msgb_put_cell_id_u(struct msgb *msg, enum CELL_IDENT id_discr, const union gsm0808_cell_id_u *u); int gsm0808_decode_cell_id_u(union gsm0808_cell_id_u *out, enum CELL_IDENT discr, const uint8_t *buf, unsigned int len); +int gsm0808_cell_id_size(enum CELL_IDENT discr); uint8_t gsm0808_enc_cause(struct msgb *msg, uint16_t cause); uint8_t gsm0808_enc_aoip_trasp_addr(struct msgb *msg, diff --git a/src/gsm/cbsp.c b/src/gsm/cbsp.c index 84b92358..c13be617 100644 --- a/src/gsm/cbsp.c +++ b/src/gsm/cbsp.c @@ -515,7 +515,7 @@ static int cbsp_decode_cell_list(struct osmo_cbsp_cell_list *cl, void *ctx, osmo_cbsp_errstr = "cell list: error decoding cell_id_union"; return rc; } - cur += rc; + cur += gsm0808_cell_id_size(cl->id_discr); llist_add_tail(&ent->list, &cl->list); } return 0; @@ -538,7 +538,7 @@ static int cbsp_decode_fail_list(struct llist_head *fl, void *ctx, osmo_cbsp_errstr = "fail list: error decoding cell_id_union"; return rc; } - cur += rc; + cur += gsm0808_cell_id_size(ent->id_discr); ent->cause = *cur++; llist_add_tail(&ent->list, fl); } @@ -562,7 +562,7 @@ static int cbsp_decode_loading_list(struct osmo_cbsp_loading_list *ll, void *ctx osmo_cbsp_errstr = "load list: error decoding cell_id_union"; return rc; } - cur += rc; + cur += gsm0808_cell_id_size(ll->id_discr); if (cur + 2 > buf + len) { talloc_free(ent); osmo_cbsp_errstr = "load list: truncated IE"; @@ -592,7 +592,7 @@ static int cbsp_decode_num_compl_list(struct osmo_cbsp_num_compl_list *cl, void osmo_cbsp_errstr = "completed list: error decoding cell_id_union"; return rc; } - cur += rc; + cur += gsm0808_cell_id_size(cl->id_discr); if (cur + 3 > buf + len) { talloc_free(ent); osmo_cbsp_errstr = "completed list: truncated IE"; diff --git a/src/gsm/gsm0808_utils.c b/src/gsm/gsm0808_utils.c index 364a04fe..7416d8f5 100644 --- a/src/gsm/gsm0808_utils.c +++ b/src/gsm/gsm0808_utils.c @@ -767,6 +767,27 @@ int gsm0808_dec_encrypt_info(struct gsm0808_encrypt_info *ei, return (int)(elem - old_elem); } +/* Return the size of the value part of a cell identifier of given type */ +int gsm0808_cell_id_size(enum CELL_IDENT discr) +{ + switch (discr) { + case CELL_IDENT_WHOLE_GLOBAL: + return 7; + case CELL_IDENT_LAC_AND_CI: + return 4; + case CELL_IDENT_CI: + return 2; + case CELL_IDENT_LAI_AND_LAC: + return 5; + case CELL_IDENT_LAC: + return 2; + case CELL_IDENT_BSS: + case CELL_IDENT_NO_CELL: + return 0; + default: + return -EINVAL; + } +} /*! Decode a single GSM 08.08 Cell ID list element payload * \param[out] out caller-provided output union * \param[in] discr Cell ID discriminator describing type to be decoded |