diff options
Diffstat (limited to 'src/gsm/ipa.c')
| -rw-r--r-- | src/gsm/ipa.c | 112 |
1 files changed, 105 insertions, 7 deletions
diff --git a/src/gsm/ipa.c b/src/gsm/ipa.c index 0c7aaad6..d423c262 100644 --- a/src/gsm/ipa.c +++ b/src/gsm/ipa.c @@ -137,6 +137,83 @@ int ipa_ccm_idtag_parse_off(struct tlv_parsed *dec, unsigned char *buf, int len, return 0; } +/*! Parse the payload part of an IPA CCM ID GET, return \ref tlv_parsed format. + * The odd payload format of those messages is structured as follows: + * * 8bit length value (length of payload *and tag*) + * * 8bit tag value + * * optional, variable-length payload + * \param[out] dec Caller-provided/allocated output structure for parsed payload + * \param[in] buf Buffer containing the payload (excluding 1 byte msg_type) of the message + * \param[in] len Length of \a buf in octets + * \returns 0 on success; negative on error */ +int ipa_ccm_id_get_parse(struct tlv_parsed *dec, const uint8_t *buf, unsigned int len) +{ + uint8_t t_len; + uint8_t t_tag; + const uint8_t *cur = buf; + + memset(dec, 0, sizeof(*dec)); + + while (len >= 2) { + len -= 2; + t_len = *cur++; + t_tag = *cur++; + + if (t_len > len + 1) { + LOGP(DLMI, LOGL_ERROR, "The tag does not fit: %d > %d\n", t_len, len + 1); + return -EINVAL; + } + + DEBUGPC(DLMI, "%s='%s' ", ipa_ccm_idtag_name(t_tag), cur); + + dec->lv[t_tag].len = t_len-1; + dec->lv[t_tag].val = cur; + + cur += t_len-1; + len -= t_len-1; + } + return 0; +} + +/*! Parse the payload part of an IPA CCM ID RESP, return \ref tlv_parsed format. + * The odd payload format of those messages is structured as follows: + * * 16bit length value (length of payload *and tag*) + * * 8bit tag value + * * optional, variable-length payload + * \param[out] dec Caller-provided/allocated output structure for parsed payload + * \param[in] buf Buffer containing the payload (excluding 1 byte msg_type) of the message + * \param[in] len Length of \a buf in octets + * \returns 0 on success; negative on error */ +int ipa_ccm_id_resp_parse(struct tlv_parsed *dec, const uint8_t *buf, unsigned int len) +{ + uint8_t t_len; + uint8_t t_tag; + const uint8_t *cur = buf; + + memset(dec, 0, sizeof(*dec)); + + while (len >= 3) { + len -= 3; + t_len = *cur++ << 8; + t_len += *cur++; + t_tag = *cur++; + + if (t_len > len + 1) { + LOGP(DLMI, LOGL_ERROR, "The tag does not fit: %d > %d\n", t_len, len + 1); + return -EINVAL; + } + + DEBUGPC(DLMI, "%s='%s' ", ipa_ccm_idtag_name(t_tag), cur); + + dec->lv[t_tag].len = t_len-1; + dec->lv[t_tag].val = cur; + + cur += t_len-1; + len -= t_len-1; + } + return 0; +} + int ipa_parse_unitid(const char *str, struct ipaccess_unit *unit_data) { unsigned long ul; @@ -251,23 +328,23 @@ struct msgb *ipa_ccm_make_id_resp(const struct ipaccess_unit *dev, break; case IPAC_IDTAG_LOCATION1: if (dev->location1) - strncpy(str, dev->location1, IPA_STRING_MAX); + osmo_strlcpy(str, dev->location1, sizeof(str)); break; case IPAC_IDTAG_LOCATION2: if (dev->location2) - strncpy(str, dev->location2, IPA_STRING_MAX); + osmo_strlcpy(str, dev->location2, sizeof(str)); break; case IPAC_IDTAG_EQUIPVERS: if (dev->equipvers) - strncpy(str, dev->equipvers, IPA_STRING_MAX); + osmo_strlcpy(str, dev->equipvers, sizeof(str)); break; case IPAC_IDTAG_SWVERSION: if (dev->swversion) - strncpy(str, dev->swversion, IPA_STRING_MAX); + osmo_strlcpy(str, dev->swversion, sizeof(str)); break; case IPAC_IDTAG_UNITNAME: if (dev->unit_name) { - snprintf(str, sizeof(str), dev->unit_name, IPA_STRING_MAX); + snprintf(str, sizeof(str), "%s", dev->unit_name); } else { snprintf(str, sizeof(str), "%02x-%02x-%02x-%02x-%02x-%02x", @@ -278,7 +355,7 @@ struct msgb *ipa_ccm_make_id_resp(const struct ipaccess_unit *dev, break; case IPAC_IDTAG_SERNR: if (dev->serno) - strncpy(str, dev->serno, IPA_STRING_MAX); + osmo_strlcpy(str, dev->serno, sizeof(str)); break; default: LOGP(DLINP, LOGL_NOTICE, @@ -286,7 +363,6 @@ struct msgb *ipa_ccm_make_id_resp(const struct ipaccess_unit *dev, msgb_free(msg); return NULL; } - str[IPA_STRING_MAX-1] = '\0'; LOGP(DLINP, LOGL_INFO, " tag %d: %s\n", ies_req[i], str); tag = msgb_put(msg, 3 + strlen(str) + 1); @@ -452,6 +528,9 @@ void ipa_prepend_header(struct msgb *msg, int proto) #ifdef HAVE_SYS_SOCKET_H #include <sys/socket.h> +/*! Read one ipa message from socket fd without caching not fully received + * messages. See \ref ipa_msg_recv_buffered for further information. + */ int ipa_msg_recv(int fd, struct msgb **rmsg) { int rc = ipa_msg_recv_buffered(fd, rmsg, NULL); @@ -462,6 +541,25 @@ int ipa_msg_recv(int fd, struct msgb **rmsg) return rc; } +/*! Read one ipa message from socket fd or store part if still not fully received. + * \param[in] fd The fd for the socket to read from. + * \param[out] rmsg internally allocated msgb containing a fully received ipa message. + * \param[inout] tmp_msg internally allocated msgb caching data for not yet fully received message. + * + * As ipa can run on top of stream based protocols such as TCP, there's the + * possibility that such lower layers split ipa messages in several low level + * packets. If a low layer packet is received containing several ipa frames, + * this function will pull from the socket and return only the first one + * available in the stream. As the socket will remain with data, it will + * trigger again during next select() and then this function will fetch the + * next ipa message, and so on. + * + * \returns -EAGAIN and allocated tmp_msg if message was not yet fully + * received. Other negative values indicate an error and cached msgb will be + * freed. 0 if socket is found dead. Positive value indicating l2 msgb len and + * rmsg pointing to internally allocated msgb containing the ipa frame on + * scucess. + */ int ipa_msg_recv_buffered(int fd, struct msgb **rmsg, struct msgb **tmp_msg) { struct msgb *msg = tmp_msg ? *tmp_msg : NULL; |