Add _buf() functions to bypass static string buffers

We have a number of static buffers in use in libosmo*.  This means
the related functions are not usable in a thread-safe way.  While
we so far don't have many multi-threaded programs in the osmocom
universe, the static buffers also prevent us from calling the same
e.g. string-ify function twice within a single printf() call.

Let's make sure there's an alternative function in all those cases,
where the user can pass in a caller-allocated buffer + size, and make
the 'classic' function with the static buffer a wrapper around that
_buf() variant.

Change-Id: Ibf85f79e93244f53b2684ff6f1095c5b41203e05

25 files changed, 362 insertions, 118 deletions

diff --git a/include/osmocom/core/msgb.h b/include/osmocom/core/msgb.h
index 5029225e..0c51ce26 100644
--- a/include/osmocom/core/msgb.h
+++ b/include/osmocom/core/msgb.h
@@ -67,6 +67,7 @@ extern struct msgb *msgb_dequeue(struct llist_head *queue);
 extern void msgb_reset(struct msgb *m);
 uint16_t msgb_length(const struct msgb *msg);
 extern const char *msgb_hexdump(const struct msgb *msg);
+char *msgb_hexdump_buf(char *buf, size_t buf_len, const struct msgb *msg);
 extern int msgb_resize_area(struct msgb *msg, uint8_t *area,
 	int old_size, int new_size);
 extern struct msgb *msgb_copy(const struct msgb *msg, const char *name);
diff --git a/include/osmocom/core/utils.h b/include/osmocom/core/utils.h
index e3728cd0..6a2b7d5b 100644
--- a/include/osmocom/core/utils.h
+++ b/include/osmocom/core/utils.h
@@ -53,6 +53,7 @@ int osmo_bcd2str(char *dst, size_t dst_size, const uint8_t *bcd, int start_nibbl
 
 int osmo_hexparse(const char *str, uint8_t *b, int max_len);
 
+char *osmo_ubit_dump_buf(char *buf, size_t buf_len, const uint8_t *bits, unsigned int len);
 char *osmo_ubit_dump(const uint8_t *bits, unsigned int len);
 char *osmo_hexdump(const unsigned char *buf, int len);
 char *osmo_hexdump_nospc(const unsigned char *buf, int len);
@@ -139,7 +140,7 @@ bool osmo_separated_identifiers_valid(const char *str, const char *sep_chars);
 const char *osmo_escape_str(const char *str, int len);
 char *osmo_escape_str_buf(const char *str, int in_len, char *buf, size_t bufsize);
 const char *osmo_quote_str(const char *str, int in_len);
-const char *osmo_quote_str_buf(const char *str, int in_len, char *buf, size_t bufsize);
+char *osmo_quote_str_buf(const char *str, int in_len, char *buf, size_t bufsize);
 
 uint32_t osmo_isqrt32(uint32_t x);
 
diff --git a/include/osmocom/gprs/gprs_ns.h b/include/osmocom/gprs/gprs_ns.h
index c62ef98a..ed155ffe 100644
--- a/include/osmocom/gprs/gprs_ns.h
+++ b/include/osmocom/gprs/gprs_ns.h
@@ -211,6 +211,8 @@ int gprs_ns_vty_init(struct gprs_ns_inst *nsi);
 
 /* Resturn peer info as string (NOTE: the buffer is allocated statically) */
 const char *gprs_ns_ll_str(const struct gprs_nsvc *nsvc);
+/* Return peer info in user-supplied buffer */
+char *gprs_ns_ll_str_buf(char *buf, size_t buf_len, const struct gprs_nsvc *nsvc);
 
 /* Copy the link layer info from other into nsvc */
 void gprs_ns_ll_copy(struct gprs_nsvc *nsvc, struct gprs_nsvc *other);
diff --git a/include/osmocom/gsm/abis_nm.h b/include/osmocom/gsm/abis_nm.h
index 823b5a45..788727cd 100644
--- a/include/osmocom/gsm/abis_nm.h
+++ b/include/osmocom/gsm/abis_nm.h
@@ -42,6 +42,7 @@ extern const struct tlv_definition abis_nm_osmo_att_tlvdef;
 extern const struct tlv_definition abis_nm_att_tlvdef_ipa;
 
 const char *abis_nm_dump_foh(const struct abis_om_fom_hdr *foh);
+char *abis_nm_dump_foh_buf(char *buf, size_t buf_len, const struct abis_om_fom_hdr *foh);
 
 /*! write a human-readable OML header to the debug log
  *  \param[in] ss Logging sub-system
diff --git a/include/osmocom/gsm/apn.h b/include/osmocom/gsm/apn.h
index 288b229e..7899bb28 100644
--- a/include/osmocom/gsm/apn.h
+++ b/include/osmocom/gsm/apn.h
@@ -11,11 +11,14 @@
 #define APN_MAXLEN	100
 
 char *osmo_apn_qualify(unsigned int mcc, unsigned int mnc, const char *ni);
+char *osmo_apn_qualify_buf(char *buf, size_t buf_len, unsigned int mcc, unsigned int mnc, const char *ni);
 
 /* Compose a string of the form '<ni>.mnc001.mcc002.gprs\0', returned in a
  * static buffer. */
 char *osmo_apn_qualify_from_imsi(const char *imsi,
 				 const char *ni, int have_3dig_mnc);
+char *osmo_apn_qualify_from_imsi_buf(char *buf, size_t buf_len, const char *imsi,
+				     const char *ni, int have_3dig_mnc);
 
 int osmo_apn_from_str(uint8_t *apn_enc, size_t max_apn_enc_len, const char *str);
 char *osmo_apn_to_str(char *out_str, const uint8_t *apn_enc, size_t apn_enc_len);
diff --git a/include/osmocom/gsm/gsm0808_utils.h b/include/osmocom/gsm/gsm0808_utils.h
index dedb0298..e2469670 100644
--- a/include/osmocom/gsm/gsm0808_utils.h
+++ b/include/osmocom/gsm/gsm0808_utils.h
@@ -69,7 +69,9 @@ struct osmo_lcls {
 };
 
 char *osmo_lcls_dump(const struct osmo_lcls *lcls);
+char *osmo_lcls_dump_buf(char *buf, size_t buf_len, const struct osmo_lcls *lcls);
 char *osmo_gcr_dump(const struct osmo_lcls *lcls);
+char *osmo_gcr_dump_buf(char *buf, size_t buf_len, const struct osmo_lcls *lcls);
 
 extern const struct value_string gsm0808_cell_id_discr_names[];
 static inline const char *gsm0808_cell_id_discr_name(enum CELL_IDENT id_discr)
@@ -251,5 +253,6 @@ static inline uint8_t gsm0808_chosen_channel(enum gsm_chan_t type, enum gsm48_ch
 }
 
 const char *gsm0808_channel_type_name(const struct gsm0808_channel_type *ct);
+char *gsm0808_channel_type_name_buf(char *buf, size_t buf_len, const struct gsm0808_channel_type *ct);
 
 /*! @} */
diff --git a/include/osmocom/gsm/gsm23003.h b/include/osmocom/gsm/gsm23003.h
index cf622ce0..88c4f3c2 100644
--- a/include/osmocom/gsm/gsm23003.h
+++ b/include/osmocom/gsm/gsm23003.h
@@ -105,13 +105,19 @@ bool osmo_msisdn_str_valid(const char *msisdn);
 bool osmo_imei_str_valid(const char *imei, bool with_15th_digit);
 
 const char *osmo_mcc_name(uint16_t mcc);
+char *osmo_mcc_name_buf(char *buf, size_t buf_len, uint16_t mcc);
 const char *osmo_mnc_name(uint16_t mnc, bool mnc_3_digits);
+char *osmo_mnc_name_buf(char *buf, size_t buf_len, uint16_t mnc, bool mnc_3_digits);
 const char *osmo_plmn_name(const struct osmo_plmn_id *plmn);
 const char *osmo_plmn_name2(const struct osmo_plmn_id *plmn);
+char *osmo_plmn_name_buf(char *buf, size_t buf_len, const struct osmo_plmn_id *plmn);
 const char *osmo_lai_name(const struct osmo_location_area_id *lai);
+char *osmo_lai_name_buf(char *buf, size_t buf_len, const struct osmo_location_area_id *lai);
 const char *osmo_cgi_name(const struct osmo_cell_global_id *cgi);
 const char *osmo_cgi_name2(const struct osmo_cell_global_id *cgi);
+char *osmo_cgi_name_buf(char *buf, size_t buf_len, const struct osmo_cell_global_id *cgi);
 const char *osmo_gummei_name(const struct osmo_gummei *gummei);
+char *osmo_gummei_name_buf(char *buf, size_t buf_len, const struct osmo_gummei *gummei);
 
 void osmo_plmn_to_bcd(uint8_t *bcd_dst, const struct osmo_plmn_id *plmn);
 void osmo_plmn_from_bcd(const uint8_t *bcd_src, struct osmo_plmn_id *plmn);
diff --git a/include/osmocom/gsm/gsm48.h b/include/osmocom/gsm/gsm48.h
index 7e0e5c48..81b2bf0d 100644
--- a/include/osmocom/gsm/gsm48.h
+++ b/include/osmocom/gsm/gsm48.h
@@ -35,6 +35,7 @@ const char *gsm48_cc_msg_name(uint8_t msgtype);
 const char *gsm48_rr_msg_name(uint8_t msgtype);
 const char *rr_cause_name(uint8_t cause);
 const char *osmo_rai_name(const struct gprs_ra_id *rai);
+char *osmo_rai_name_buf(char *buf, size_t buf_len, const struct gprs_ra_id *rai);
 
 int gsm48_decode_lai(struct gsm48_loc_area_id *lai, uint16_t *mcc,
 		     uint16_t *mnc, uint16_t *lac)
@@ -55,6 +56,7 @@ int gsm48_mi_to_string(char *string, const int str_len,
 			const uint8_t *mi, const int mi_len);
 const char *gsm48_mi_type_name(uint8_t mi);
 const char *osmo_mi_name(const uint8_t *mi, uint8_t mi_len);
+char *osmo_mi_name_buf(char *buf, size_t buf_len, const uint8_t *mi, uint8_t mi_len);
 
 /* Parse Routeing Area Identifier */
 void gsm48_parse_ra(struct gprs_ra_id *raid, const uint8_t *buf);
diff --git a/include/osmocom/gsm/gsm_utils.h b/include/osmocom/gsm/gsm_utils.h
index f8f72a7f..f48cc68f 100644
--- a/include/osmocom/gsm/gsm_utils.h
+++ b/include/osmocom/gsm/gsm_utils.h
@@ -180,6 +180,7 @@ uint32_t gsm_gsmtime2fn(struct gsm_time *time);
 
 /* Returns static buffer with string representation of a GSM Time */
 char *osmo_dump_gsmtime(const struct gsm_time *tm);
+char *osmo_dump_gsmtime_buf(char *buf, size_t buf_len, const struct gsm_time *tm);
 
 /* GSM TS 03.03 Chapter 2.6 */
 enum gprs_tlli_type {
diff --git a/include/osmocom/gsm/protocol/gsm_04_08.h b/include/osmocom/gsm/protocol/gsm_04_08.h
index c052e4c8..c97df168 100644
--- a/include/osmocom/gsm/protocol/gsm_04_08.h
+++ b/include/osmocom/gsm/protocol/gsm_04_08.h
@@ -70,6 +70,7 @@ bool osmo_gsm48_classmark1_is_r99(const struct gsm48_classmark1 *cm1);
 bool osmo_gsm48_classmark2_is_r99(const struct gsm48_classmark2 *cm2, uint8_t cm2_len);
 int osmo_gsm48_classmark_supports_a5(const struct osmo_gsm48_classmark *cm, uint8_t a5);
 const char *osmo_gsm48_classmark_a5_name(const struct osmo_gsm48_classmark *cm);
+char *osmo_gsm48_classmark_a5_name_buf(char *buf, size_t buf_len, const struct osmo_gsm48_classmark *cm);
 void osmo_gsm48_classmark_update(struct osmo_gsm48_classmark *dst, const struct osmo_gsm48_classmark *src);
 
 /* Chapter 10.5.2.1b.3 */
@@ -1643,6 +1644,7 @@ extern const struct value_string gsm48_rr_msgtype_names[];
 extern const struct value_string gsm48_mm_msgtype_names[];
 extern const struct value_string gsm48_cc_msgtype_names[];
 const char *gsm48_pdisc_msgtype_name(uint8_t pdisc, uint8_t msg_type);
+char *gsm48_pdisc_msgtype_name_buf(char *buf, size_t buf_len, uint8_t pdisc, uint8_t msg_type);
 
 /* FIXME: Table 10.4 / 10.4a (GPRS) */
 
diff --git a/include/osmocom/gsm/rsl.h b/include/osmocom/gsm/rsl.h
index be0fa797..4a1da3a6 100644
--- a/include/osmocom/gsm/rsl.h
+++ b/include/osmocom/gsm/rsl.h
@@ -30,6 +30,7 @@ uint8_t rsl_enc_chan_nr(uint8_t type, uint8_t subch, uint8_t timeslot);
 /* decode channel number as per Section 9.3.1 */
 int rsl_dec_chan_nr(uint8_t chan_nr, uint8_t *type, uint8_t *subch, uint8_t *timeslot);
 /* Turns channel number into a string */
+char *rsl_chan_nr_str_buf(char *buf, size_t buf_len, uint8_t chan_nr);
 const char *rsl_chan_nr_str(uint8_t chan_nr);
 
 
diff --git a/include/osmocom/sim/sim.h b/include/osmocom/sim/sim.h
index 680cad15..0490dcd4 100644
--- a/include/osmocom/sim/sim.h
+++ b/include/osmocom/sim/sim.h
@@ -296,6 +296,7 @@ enum osim_card_sw_class osim_sw_class(const struct osim_card_profile *cp,
 					uint16_t sw_in);
 
 struct osim_card_hdl;
+char *osim_print_sw_buf(char *buf, size_t buf_len, const struct osim_card_hdl *ch, uint16_t sw_in);
 char *osim_print_sw(const struct osim_card_hdl *ch, uint16_t sw_in);
 
 extern const struct tlv_definition ts102221_fcp_tlv_def;
diff --git a/src/gb/gprs_ns.c b/src/gb/gprs_ns.c
index c7ff78ed..fc120cec 100644
--- a/src/gb/gprs_ns.c
+++ b/src/gb/gprs_ns.c
@@ -1525,17 +1525,15 @@ int gprs_ns_rcvmsg(struct gprs_ns_inst *nsi, struct msgb *msg,
 	return rc;
 }
 
-const char *gprs_ns_ll_str(const struct gprs_nsvc *nsvc)
+char *gprs_ns_ll_str_buf(char *buf, size_t buf_len, const struct gprs_nsvc *nsvc)
 {
-	static char buf[80];
-
 	switch(nsvc->ll) {
 	case GPRS_NS_LL_UDP:
-		snprintf(buf, sizeof(buf), "%s:%u",
+		snprintf(buf, buf_len, "%s:%u",
 			 inet_ntoa(nsvc->ip.bts_addr.sin_addr), osmo_ntohs(nsvc->ip.bts_addr.sin_port));
 		break;
 	case GPRS_NS_LL_FR_GRE:
-		snprintf(buf, sizeof(buf), "%s:%u",
+		snprintf(buf, buf_len, "%s:%u",
 			 inet_ntoa(nsvc->frgre.bts_addr.sin_addr), osmo_ntohs(nsvc->frgre.bts_addr.sin_port));
 		break;
 	default:
@@ -1543,11 +1541,17 @@ const char *gprs_ns_ll_str(const struct gprs_nsvc *nsvc)
 		break;
 	}
 
-	buf[sizeof(buf) - 1] = '\0';
+	buf[buf_len - 1] = '\0';
 
 	return buf;
 }
 
+const char *gprs_ns_ll_str(const struct gprs_nsvc *nsvc)
+{
+	static char buf[80];
+	return gprs_ns_ll_str_buf(buf, sizeof(buf), nsvc);
+}
+
 void gprs_ns_ll_copy(struct gprs_nsvc *nsvc, struct gprs_nsvc *other)
 {
 	nsvc->ll = other->ll;
diff --git a/src/gb/libosmogb.map b/src/gb/libosmogb.map
index 2ad3ff71..21929da1 100644
--- a/src/gb/libosmogb.map
+++ b/src/gb/libosmogb.map
@@ -64,6 +64,7 @@ gprs_ns_tx_status;
 gprs_ns_tx_unblock;
 gprs_ns_vty_init;
 gprs_ns_ll_str;
+gprs_ns_ll_str_buf;
 gprs_ns_ll_copy;
 gprs_ns_ll_clear;
 gprs_ns_msgb_alloc;
diff --git a/src/gsm/abis_nm.c b/src/gsm/abis_nm.c
index 49d05ba5..e25fdd03 100644
--- a/src/gsm/abis_nm.c
+++ b/src/gsm/abis_nm.c
@@ -928,14 +928,19 @@ enum gsm_phys_chan_config abis_nm_pchan4chcomb(uint8_t chcomb)
 	return GSM_PCHAN_NONE;
 }
 
-const char *abis_nm_dump_foh(const struct abis_om_fom_hdr *foh)
+char *abis_nm_dump_foh_buf(char *buf, size_t buf_len, const struct abis_om_fom_hdr *foh)
 {
-	static char foh_buf[128];
-	snprintf(foh_buf, sizeof(foh_buf), "OC=%s(%02x) INST=(%02x,%02x,%02x)",
+	snprintf(buf, buf_len, "OC=%s(%02x) INST=(%02x,%02x,%02x)",
 		get_value_string(abis_nm_obj_class_names, foh->obj_class),
 		foh->obj_class, foh->obj_inst.bts_nr, foh->obj_inst.trx_nr,
 		foh->obj_inst.ts_nr);
-	return foh_buf;
+	return buf;
+}
+
+const char *abis_nm_dump_foh(const struct abis_om_fom_hdr *foh)
+{
+	static char foh_buf[128];
+	return abis_nm_dump_foh_buf(foh_buf, sizeof(foh_buf), foh);
 }
 
 /* this is just for compatibility reasons, it is now a macro */
diff --git a/src/gsm/apn.c b/src/gsm/apn.c
index 26746631..4ab370c5 100644
--- a/src/gsm/apn.c
+++ b/src/gsm/apn.c
@@ -32,17 +32,22 @@
 
 static char apn_strbuf[APN_MAXLEN+1];
 
-char *osmo_apn_qualify(unsigned int mcc, unsigned int mnc, const char *ni)
+char *osmo_apn_qualify_buf(char *buf, size_t buf_len, unsigned int mcc, unsigned int mnc, const char *ni)
 {
-	snprintf(apn_strbuf, sizeof(apn_strbuf)-1, APN_GPRS_FMT,
-		ni, mnc, mcc);
-	apn_strbuf[sizeof(apn_strbuf)-1] = '\0';
+	snprintf(buf, buf_len-1, APN_GPRS_FMT, ni, mnc, mcc);
+	buf[buf_len-1] = '\0';
 
-	return apn_strbuf;
+	return buf;
 }
 
-char *osmo_apn_qualify_from_imsi(const char *imsi,
-				 const char *ni, int have_3dig_mnc)
+char *osmo_apn_qualify(unsigned int mcc, unsigned int mnc, const char *ni)
+{
+	return osmo_apn_qualify_buf(apn_strbuf, sizeof(apn_strbuf), mcc, mnc, ni);
+}
+
+
+char *osmo_apn_qualify_from_imsi_buf(char *buf, size_t buf_len, const char *imsi,
+				     const char *ni, int have_3dig_mnc)
 {
 	char cbuf[3+1], nbuf[3+1];
 
@@ -56,7 +61,13 @@ char *osmo_apn_qualify_from_imsi(const char *imsi,
 		strncpy(nbuf, imsi+3, 2);
 		nbuf[2] = '\0';
 	}
-	return osmo_apn_qualify(atoi(cbuf), atoi(nbuf), ni);
+	return osmo_apn_qualify_buf(buf, buf_len, atoi(cbuf), atoi(nbuf), ni);
+}
+
+char *osmo_apn_qualify_from_imsi(const char *imsi,
+				 const char *ni, int have_3dig_mnc)
+{
+	return osmo_apn_qualify_from_imsi_buf(apn_strbuf, sizeof(apn_strbuf), imsi, ni, have_3dig_mnc);
 }
 
 /**
diff --git a/src/gsm/gsm0808_utils.c b/src/gsm/gsm0808_utils.c
index e0cdaaf6..52e46743 100644
--- a/src/gsm/gsm0808_utils.c
+++ b/src/gsm/gsm0808_utils.c
@@ -595,11 +595,13 @@ int gsm0808_dec_lcls(struct osmo_lcls *lcls, const struct tlv_parsed *tp)
 static char dbuf[256];
 
 /*! Dump LCLS parameters (GCR excluded) into string for printing.
+ *  \param[out] buf caller-allocated output string buffer
+ *  \param[in] buf_len size of buf in bytes
  *  \param[in] lcls pointer to the struct to print.
  *  \returns string representation of LCLS or NULL on error. */
-char *osmo_lcls_dump(const struct osmo_lcls *lcls)
+char *osmo_lcls_dump_buf(char *buf, size_t buf_len, const struct osmo_lcls *lcls)
 {
-	struct osmo_strbuf s = { .buf = dbuf, .len = 256 };
+	struct osmo_strbuf s = { .buf = buf, .len = buf_len };
 
 	if (!lcls)
 		return NULL;
@@ -612,12 +614,22 @@ char *osmo_lcls_dump(const struct osmo_lcls *lcls)
 	return dbuf;
 }
 
+/*! Dump LCLS parameters (GCR excluded) into static string buffer for printing.
+ *  \param[in] lcls pointer to the struct to print.
+ *  \returns string representation of LCLS in static buffer or NULL on error. */
+char *osmo_lcls_dump(const struct osmo_lcls *lcls)
+{
+	return osmo_lcls_dump_buf(dbuf, sizeof(dbuf), lcls);
+}
+
 /*! Dump GCR struct into string for printing.
+ *  \param[out] buf caller-allocated output string buffer
+ *  \param[in] buf_len size of buf in bytes
  *  \param[in] lcls pointer to the struct to print.
  *  \returns string representation of GCR or NULL on error. */
-char *osmo_gcr_dump(const struct osmo_lcls *lcls)
+char *osmo_gcr_dump_buf(char *buf, size_t buf_len, const struct osmo_lcls *lcls)
 {
-	struct osmo_strbuf s = { .buf = dbuf, .len = 256 };
+	struct osmo_strbuf s = { .buf = buf, .len = buf_len };
 
 	if (!lcls)
 		return NULL;
@@ -631,6 +643,15 @@ char *osmo_gcr_dump(const struct osmo_lcls *lcls)
 	return dbuf;
 }
 
+/*! Dump GCR struct into static string buffer for printing.
+ *  \param[in] lcls pointer to the struct to print.
+ *  \returns string representation of GCR in static buffer or NULL on error. */
+char *osmo_gcr_dump(const struct osmo_lcls *lcls)
+{
+	return osmo_gcr_dump_buf(dbuf, sizeof(dbuf), lcls);
+}
+
+
 /*! Encode TS 08.08 Encryption Information IE
  *  \param[out] msg Message Buffer to which IE is to be appended
  *  \param[in] ei Encryption Information to be encoded
@@ -1838,13 +1859,18 @@ const char *gsm0808_cell_id_list_name(const struct gsm0808_cell_id_list2 *cil)
 #undef APPEND_STR
 #undef APPEND_CELL_ID_U
 
-const char *gsm0808_channel_type_name(const struct gsm0808_channel_type *ct)
+char *gsm0808_channel_type_name_buf(char *buf, size_t buf_len, const struct gsm0808_channel_type *ct)
 {
-	static char buf[128];
-	snprintf(buf, sizeof(buf), "ch_indctr=0x%x ch_rate_type=0x%x perm_spch=%s",
+	snprintf(buf, buf_len, "ch_indctr=0x%x ch_rate_type=0x%x perm_spch=%s",
 		 ct->ch_indctr, ct->ch_rate_type,
 		 osmo_hexdump(ct->perm_spch, ct->perm_spch_len));
 	return buf;
 }
 
+const char *gsm0808_channel_type_name(const struct gsm0808_channel_type *ct)
+{
+	static char buf[128];
+	return gsm0808_channel_type_name_buf(buf, sizeof(buf), ct);
+}
+
 /*! @} */
diff --git a/src/gsm/gsm23003.c b/src/gsm/gsm23003.c
index 720c09b6..bbfe236a 100644
--- a/src/gsm/gsm23003.c
+++ b/src/gsm/gsm23003.c
@@ -90,13 +90,37 @@ bool osmo_imei_str_valid(const char *imei, bool with_15th_digit)
 }
 
 /*! Return MCC string as standardized 3-digit with leading zeros.
+ * \param[out] buf caller-allocated output buffer
+ * \param[in] buf_len size of buf in bytes
+ * \param[in] mcc  MCC value.
+ * \returns string in user-supplied output buffer
+ */
+char *osmo_mcc_name_buf(char *buf, size_t buf_len, uint16_t mcc)
+{
+	snprintf(buf, buf_len, "%03u", mcc);
+	return buf;
+}
+
+/*! Return MCC string as standardized 3-digit with leading zeros.
  * \param[in] mcc  MCC value.
  * \returns string in static buffer.
  */
 const char *osmo_mcc_name(uint16_t mcc)
 {
 	static char buf[8];
-	snprintf(buf, sizeof(buf), "%03u", mcc);
+	return osmo_mcc_name_buf(buf, sizeof(buf), mcc);
+}
+
+/*! Return MNC string as standardized 2- or 3-digit with leading zeros.
+ * \param[out] buf caller-allocated output buffer
+ * \param[in] buf_len size of buf in bytes
+ * \param[in] mnc  MNC value.
+ * \param[in] mnc_3_digits  True if an MNC should fill three digits, only has an effect if MNC < 100.
+ * \returns string in static buffer.
+ */
+char *osmo_mnc_name_buf(char *buf, size_t buf_len, uint16_t mnc, bool mnc_3_digits)
+{
+	snprintf(buf, buf_len, "%0*u", mnc_3_digits ? 3 : 2, mnc);
 	return buf;
 }
 
@@ -108,14 +132,21 @@ const char *osmo_mcc_name(uint16_t mcc)
 const char *osmo_mnc_name(uint16_t mnc, bool mnc_3_digits)
 {
 	static char buf[8];
-	snprintf(buf, sizeof(buf), "%0*u", mnc_3_digits ? 3 : 2, mnc);
-	return buf;
+	return osmo_mnc_name_buf(buf, sizeof(buf), mnc, mnc_3_digits);
 }
 
-static inline void plmn_name(char *buf, size_t buflen, const struct osmo_plmn_id *plmn)
+/*! Return MCC-MNC string as standardized 3-digit-dash-2/3-digit with leading zeros.
+ * \param[out] buf caller-allocated output buffer
+ * \param[in] buf_len size of buf in bytes
+ * \param[in] plmn  MCC-MNC value.
+ * \returns string in static buffer.
+ */
+char *osmo_plmn_name_buf(char *buf, size_t buf_len, const struct osmo_plmn_id *plmn)
 {
-	snprintf(buf, buflen, "%s-%s", osmo_mcc_name(plmn->mcc),
-		 osmo_mnc_name(plmn->mnc, plmn->mnc_3_digits));
+	char mcc[8], mnc[8];
+	snprintf(buf, buf_len, "%s-%s", osmo_mcc_name_buf(mcc, sizeof(mcc), plmn->mcc),
+		 osmo_mnc_name_buf(mnc, sizeof(mnc), plmn->mnc, plmn->mnc_3_digits));
+	return buf;
 }
 
 /*! Return MCC-MNC string as standardized 3-digit-dash-2/3-digit with leading zeros.
@@ -125,10 +156,10 @@ static inline void plmn_name(char *buf, size_t buflen, const struct osmo_plmn_id
 const char *osmo_plmn_name(const struct osmo_plmn_id *plmn)
 {
 	static char buf[16];
-	plmn_name(buf, sizeof(buf), plmn);
-	return buf;
+	return osmo_plmn_name_buf(buf, sizeof(buf), plmn);
 }
 
+
 /*! Same as osmo_plmn_name(), but returning in a different static buffer.
  * \param[in] plmn  MCC-MNC value.
  * \returns string in static buffer.
@@ -136,7 +167,19 @@ const char *osmo_plmn_name(const struct osmo_plmn_id *plmn)
 const char *osmo_plmn_name2(const struct osmo_plmn_id *plmn)
 {
 	static char buf[16];
-	plmn_name(buf, sizeof(buf), plmn);
+	return osmo_plmn_name_buf(buf, sizeof(buf), plmn);
+}
+
+/*! Return MCC-MNC-LAC as string, in caller-provided output buffer.
+ * \param[out] buf caller-allocated output buffer
+ * \param[in] buf_len size of buf in bytes
+ * \param[in] lai  LAI to encode, the rac member is ignored.
+ * \returns buf
+ */
+char *osmo_lai_name_buf(char *buf, size_t buf_len, const struct osmo_location_area_id *lai)
+{
+	char plmn[16];
+	snprintf(buf, buf_len, "%s-%u", osmo_plmn_name_buf(plmn, sizeof(plmn), &lai->plmn), lai->lac);
 	return buf;
 }
 
@@ -147,13 +190,18 @@ const char *osmo_plmn_name2(const struct osmo_plmn_id *plmn)
 const char *osmo_lai_name(const struct osmo_location_area_id *lai)
 {
 	static char buf[32];
-	snprintf(buf, sizeof(buf), "%s-%u", osmo_plmn_name(&lai->plmn), lai->lac);
-	return buf;
+	return osmo_lai_name_buf(buf, sizeof(buf), lai);
 }
 
-static const char *_cgi_name(const struct osmo_cell_global_id *cgi, char *buf, size_t buflen)
+/*! Return MCC-MNC-LAC-CI as string, in caller-provided output buffer.
+ * \param[out] buf caller-allocated output buffer
+ * \param[in] buf_len size of buf in bytes
+ * \param[in] cgi  CGI to encode.
+ * \returns buf
+ */
+char *osmo_cgi_name_buf(char *buf, size_t buf_len, const struct osmo_cell_global_id *cgi)
 {
-	snprintf(buf, buflen, "%s-%u", osmo_lai_name(&cgi->lai), cgi->cell_identity);
+	snprintf(buf, buf_len, "%s-%u", osmo_lai_name(&cgi->lai), cgi->cell_identity);
 	return buf;
 }
 
@@ -164,7 +212,7 @@ static const char *_cgi_name(const struct osmo_cell_global_id *cgi, char *buf, s
 const char *osmo_cgi_name(const struct osmo_cell_global_id *cgi)
 {
 	static char buf[32];
-	return _cgi_name(cgi, buf, sizeof(buf));
+	return osmo_cgi_name_buf(buf, sizeof(buf), cgi);
 }
 
 /*! Same as osmo_cgi_name(), but uses a different static buffer.
@@ -175,7 +223,7 @@ const char *osmo_cgi_name(const struct osmo_cell_global_id *cgi)
 const char *osmo_cgi_name2(const struct osmo_cell_global_id *cgi)
 {
 	static char buf[32];
-	return _cgi_name(cgi, buf, sizeof(buf));
+	return osmo_cgi_name_buf(buf, sizeof(buf), cgi);
 }
 
 static void to_bcd(uint8_t *bcd, uint16_t val)
@@ -187,14 +235,31 @@ static void to_bcd(uint8_t *bcd, uint16_t val)
 	bcd[0] = val % 10;
 }
 
-const char *osmo_gummei_name(const struct osmo_gummei *gummei)
+/*! Return string representation of GUMMEI in caller-provided output buffer.
+ * \param[out] buf pointer to caller-provided output buffer
+ * \param[in] buf_len size of buf in bytes
+ * \param[in] gummei GUMMEI to be stringified
+ * \returns buf
+ */
+char *osmo_gummei_name_buf(char *buf, size_t buf_len, const struct osmo_gummei *gummei)
 {
-	static char buf[32];
-	snprintf(buf, sizeof(buf), "%s-%04x-%02x", osmo_plmn_name(&gummei->plmn),
+	char plmn[16];
+	snprintf(buf, buf_len, "%s-%04x-%02x", osmo_plmn_name_buf(plmn, sizeof(plmn), &gummei->plmn),
 		 gummei->mme.group_id, gummei->mme.code);
 	return buf;
 }
 
+/*! Return string representation of GUMMEI in static output buffer.
+ * \param[in] gummei GUMMEI to be stringified
+ * \returns pointer to static output buffer
+ */
+const char *osmo_gummei_name(const struct osmo_gummei *gummei)
+{
+	static char buf[32];
+	return osmo_gummei_name_buf(buf, sizeof(buf), gummei);
+}
+
+
 /* Convert MCC + MNC to BCD representation
  * \param[out] bcd_dst caller-allocated memory for output
  * \param[in] mcc Mobile Country Code
diff --git a/src/gsm/gsm48.c b/src/gsm/gsm48.c
index 5dc30ad0..a45d67bc 100644
--- a/src/gsm/gsm48.c
+++ b/src/gsm/gsm48.c
@@ -182,6 +182,20 @@ const char *rr_cause_name(uint8_t cause)
 	return get_value_string(rr_cause_names, cause);
 }
 
+/*! Return MCC-MNC-LAC-RAC as string, in a caller-provided output buffer.
+ * \param[out] buf caller-provided output buffer
+ * \param[in] buf_len size of buf in bytes
+ * \param[in] rai  RAI to encode.
+ * \returns buf
+ */
+char *osmo_rai_name_buf(char *buf, size_t buf_len, const struct gprs_ra_id *rai)
+{
+	snprintf(buf, buf_len, "%s-%s-%u-%u",
+		 osmo_mcc_name(rai->mcc), osmo_mnc_name(rai->mnc, rai->mnc_3_digits), rai->lac,
+		 rai->rac);
+	return buf;
+}
+
 /*! Return MCC-MNC-LAC-RAC as string, in a static buffer.
  * \param[in] rai  RAI to encode.
  * \returns Static string buffer.
@@ -189,10 +203,7 @@ const char *rr_cause_name(uint8_t cause)
 const char *osmo_rai_name(const struct gprs_ra_id *rai)
 {
 	static char buf[32];
-	snprintf(buf, sizeof(buf), "%s-%s-%u-%u",
-		 osmo_mcc_name(rai->mcc), osmo_mnc_name(rai->mnc, rai->mnc_3_digits), rai->lac,
-		 rai->rac);
-	return buf;
+	return osmo_rai_name_buf(buf, sizeof(buf), rai);
 }
 
 /* FIXME: convert to value_string */
@@ -433,14 +444,15 @@ const char *gsm48_mi_type_name(uint8_t mi)
 	return get_value_string(mi_type_names, mi);
 }
 
-/*! Return a human readable representation of a Mobile Identity in static buffer.
+/*! Return a human readable representation of a Mobile Identity in caller-provided buffer.
+ * \param[out] buf caller-provided output buffer
+ * \param[in] buf_len size of buf in bytes
  * \param[in] mi  Mobile Identity buffer containing 3GPP TS 04.08 style MI type and data.
  * \param[in] mi_len  Length of mi.
- * \return A string like "IMSI-1234567", "TMSI-0x1234ABCD" or "unknown", "TMSI-invalid"...
+ * \return buf
  */
-const char *osmo_mi_name(const uint8_t *mi, uint8_t mi_len)
+char *osmo_mi_name_buf(char *buf, size_t buf_len, const uint8_t *mi, uint8_t mi_len)
 {
-	static char mi_name[10 + GSM48_MI_SIZE + 1];
 	uint8_t mi_type;
 	uint32_t tmsi;
 	char mi_string[GSM48_MI_SIZE];
@@ -452,8 +464,8 @@ const char *osmo_mi_name(const uint8_t *mi, uint8_t mi_len)
 		/* Table 10.5.4.3, reverse generate_mid_from_tmsi */
 		if (mi_len == GSM48_TMSI_LEN && mi[0] == (0xf0 | GSM_MI_TYPE_TMSI)) {
 			tmsi = osmo_load32be(&mi[1]);
-			snprintf(mi_name, sizeof(mi_name), "TMSI-0x%08" PRIX32, tmsi);
-			return mi_name;
+			snprintf(buf, buf_len, "TMSI-0x%08" PRIX32, tmsi);
+			return buf;
 		}
 		return "TMSI-invalid";
 
@@ -461,14 +473,25 @@ const char *osmo_mi_name(const uint8_t *mi, uint8_t mi_len)
 	case GSM_MI_TYPE_IMEI:
 	case GSM_MI_TYPE_IMEISV:
 		osmo_bcd2str(mi_string, sizeof(mi_string), mi, 1, (mi_len * 2) - (mi[0] & GSM_MI_ODD ? 0 : 1), true);
-		snprintf(mi_name, sizeof(mi_name), "%s-%s", gsm48_mi_type_name(mi_type), mi_string);
-		return mi_name;
+		snprintf(buf, buf_len, "%s-%s", gsm48_mi_type_name(mi_type), mi_string);
+		return buf;
 
 	default:
 		return "unknown";
 	}
 }
 
+/*! Return a human readable representation of a Mobile Identity in static buffer.
+ * \param[in] mi  Mobile Identity buffer containing 3GPP TS 04.08 style MI type and data.
+ * \param[in] mi_len  Length of mi.
+ * \return A string like "IMSI-1234567", "TMSI-0x1234ABCD" or "unknown", "TMSI-invalid"...
+ */
+const char *osmo_mi_name(const uint8_t *mi, uint8_t mi_len)
+{
+	static char mi_name[10 + GSM48_MI_SIZE + 1];
+	return osmo_mi_name_buf(mi_name, sizeof(mi_name), mi, mi_len);
+}
+
 /*! Checks is particular message is cipherable in A/Gb mode according to
  *         3GPP TS 24.008 § 4.7.1.2
  *  \param[in] hdr Message header
@@ -1050,16 +1073,17 @@ const struct value_string gsm48_nc_ss_msgtype_names[] = {
 	{ 0, NULL }
 };
 
-/*! Compose a string naming the message type for given protocol.
+/*! Compose a string naming the message type for given protocol, in a caller-provided buffer.
  * If the message type string is known, return the message type name, otherwise
  * return "<protocol discriminator name>:<message type in hex>".
+ * \param[out] buf caller-allcated output string buffer
+ * \param[in] buf_len size of buf in bytes
  * \param[in] pdisc protocol discriminator like GSM48_PDISC_MM
  * \param[in] msg_type message type like GSM48_MT_MM_LOC_UPD_REQUEST
- * \returns statically allocated string or string constant.
+ * \returns buf
  */
-const char *gsm48_pdisc_msgtype_name(uint8_t pdisc, uint8_t msg_type)
+char *gsm48_pdisc_msgtype_name_buf(char *buf, size_t buf_len, uint8_t pdisc, uint8_t msg_type)
 {
-	static char namebuf[64];
 	const struct value_string *msgt_names;
 
 	switch (pdisc) {
@@ -1081,11 +1105,23 @@ const char *gsm48_pdisc_msgtype_name(uint8_t pdisc, uint8_t msg_type)
 	}
 
 	if (msgt_names)
-		return get_value_string(msgt_names, msg_type);
+		snprintf(buf, buf_len, "%s", get_value_string(msgt_names, msg_type));
+	else
+		snprintf(buf, buf_len, "%s:0x%02x", gsm48_pdisc_name(pdisc), msg_type);
+	return buf;
+}
 
-	snprintf(namebuf, sizeof(namebuf), "%s:0x%02x",
-		 gsm48_pdisc_name(pdisc), msg_type);
-	return namebuf;
+/*! Compose a string naming the message type for given protocol, in a static buffer.
+