isisd: Don't use structs to encode/decode PDU header

Signed-off-by: Christian Franke <chris@opensourcerouting.org>

diff --git a/isisd/isis_lsp.c b/isisd/isis_lsp.c
index 40c6141ab8128a5bdbea2085388a9c4fdab0fb3f..1bea8c8c94fafdd10f636ed78b865c91e81a5ad2 100644 (file)
--- a/isisd/isis_lsp.c
+++ b/isisd/isis_lsp.c
@@ -468,7 +468,6 @@ static void lsp_update_data(struct isis_lsp *lsp, struct stream *stream,
        lsp->pdu = stream_dup(stream);
 
        /* setting pointers to the correct place */
-       lsp->isis_header = (struct isis_fixed_hdr *)(STREAM_DATA(lsp->pdu));
        lsp->lsp_header = (struct isis_link_state_hdr *)(STREAM_DATA(lsp->pdu)
                                                         + ISIS_FIXED_HDR_LEN);
        lsp->area = area;
@@ -580,6 +579,8 @@ struct isis_lsp *lsp_new(struct isis_area *area, u_char *lsp_id,
                         u_int8_t lsp_bits, u_int16_t checksum, int level)
 {
        struct isis_lsp *lsp;
+       uint8_t pdu_type =
+               (level == IS_LEVEL_1) ? L1_LINK_STATE : L2_LINK_STATE;
 
        lsp = XCALLOC(MTYPE_ISIS_LSP, sizeof(struct isis_lsp));
        lsp->area = area;
@@ -587,16 +588,13 @@ struct isis_lsp *lsp_new(struct isis_area *area, u_char *lsp_id,
        lsp->pdu = stream_new(LLC_LEN + area->lsp_mtu);
        if (LSP_FRAGMENT(lsp_id) == 0)
                lsp->lspu.frags = list_new();
-       lsp->isis_header = (struct isis_fixed_hdr *)(STREAM_DATA(lsp->pdu));
-       lsp->lsp_header = (struct isis_link_state_hdr *)(STREAM_DATA(lsp->pdu)
-                                                        + ISIS_FIXED_HDR_LEN);
 
-       /* at first we fill the FIXED HEADER */
-       (level == IS_LEVEL_1) ? fill_fixed_hdr(lsp->isis_header, L1_LINK_STATE)
-                             : fill_fixed_hdr(lsp->isis_header, L2_LINK_STATE);
+       fill_fixed_hdr(pdu_type, lsp->pdu);
 
        /* now for the LSP HEADER */
        /* Minimal LSP PDU size */
+       lsp->lsp_header = (struct isis_link_state_hdr *)(STREAM_DATA(lsp->pdu)
+                                                        + ISIS_FIXED_HDR_LEN);
        lsp->lsp_header->pdu_len = htons(ISIS_FIXED_HDR_LEN + ISIS_LSP_HDR_LEN);
        memcpy(lsp->lsp_header->lsp_id, lsp_id, ISIS_SYS_ID_LEN + 2);
        lsp->lsp_header->checksum = checksum; /* Provided in network order */
@@ -2972,6 +2970,8 @@ void lsp_purge_non_exist(int level, struct isis_link_state_hdr *lsp_hdr,
                         struct isis_area *area)
 {
        struct isis_lsp *lsp;
+       uint8_t pdu_type =
+               (level == IS_LEVEL_1) ? L1_LINK_STATE : L2_LINK_STATE;
 
        /*
         * We need to create the LSP to be purged
@@ -2980,10 +2980,8 @@ void lsp_purge_non_exist(int level, struct isis_link_state_hdr *lsp_hdr,
        lsp->area = area;
        lsp->level = level;
        lsp->pdu = stream_new(LLC_LEN + area->lsp_mtu);
-       lsp->isis_header = (struct isis_fixed_hdr *)STREAM_DATA(lsp->pdu);
-       fill_fixed_hdr(lsp->isis_header,
-                      (lsp->level == IS_LEVEL_1) ? L1_LINK_STATE
-                                                 : L2_LINK_STATE);
+       fill_fixed_hdr(pdu_type, lsp->pdu);
+
        lsp->lsp_header = (struct isis_link_state_hdr *)(STREAM_DATA(lsp->pdu)
                                                         + ISIS_FIXED_HDR_LEN);
        memcpy(lsp->lsp_header, lsp_hdr, ISIS_LSP_HDR_LEN);

diff --git a/isisd/isis_lsp.h b/isisd/isis_lsp.h
index 7bec162719cedafd4025980083837c8c39398483..f149b689641539f972220811fbe0b818cbea0962 100644 (file)
--- a/isisd/isis_lsp.h
+++ b/isisd/isis_lsp.h
@@ -29,7 +29,6 @@
  * We will have to split the header into two parts, and for readability
  * sake it should better be avoided */
 struct isis_lsp {
-       struct isis_fixed_hdr *isis_header;     /* normally equals pdu */
        struct isis_link_state_hdr *lsp_header; /* pdu + isis_header_len */
        struct stream *pdu;                     /* full pdu lsp */
        union {

diff --git a/isisd/isis_pdu.c b/isisd/isis_pdu.c
index a3706179a6b305a06f66d16c5025ac90e4f02835..937bd3bbe8ce92de38302e75bdb2f3f7112fa9ee 100644 (file)
--- a/isisd/isis_pdu.c
+++ b/isisd/isis_pdu.c
@@ -1888,59 +1888,103 @@ static int process_psnp(int level, struct isis_circuit *circuit,
        return process_snp(ISIS_SNP_PSNP_FLAG, level, circuit, ssnpa);
 }
 
+static int pdu_size(uint8_t pdu_type, uint8_t *size)
+{
+       switch (pdu_type) {
+       case L1_LAN_HELLO:
+       case L2_LAN_HELLO:
+               *size = ISIS_LANHELLO_HDRLEN;
+               break;
+       case P2P_HELLO:
+               *size = ISIS_P2PHELLO_HDRLEN;
+               break;
+       case L1_LINK_STATE:
+       case L2_LINK_STATE:
+               *size = ISIS_LSP_HDR_LEN;
+               break;
+       case L1_COMPLETE_SEQ_NUM:
+       case L2_COMPLETE_SEQ_NUM:
+               *size = ISIS_CSNP_HDRLEN;
+               break;
+       case L1_PARTIAL_SEQ_NUM:
+       case L2_PARTIAL_SEQ_NUM:
+               *size = ISIS_PSNP_HDRLEN;
+               break;
+       default:
+               return 1;
+       }
+       *size += ISIS_FIXED_HDR_LEN;
+       return 0;
+}
+
 /*
  * PDU Dispatcher
  */
 
 static int isis_handle_pdu(struct isis_circuit *circuit, u_char *ssnpa)
 {
-       struct isis_fixed_hdr *hdr;
-
        int retval = ISIS_OK;
 
-       /*
-        * Let's first read data from stream to the header
-        */
-       hdr = (struct isis_fixed_hdr *)STREAM_DATA(circuit->rcv_stream);
+       /* Verify that at least the 8 bytes fixed header have been received */
+       if (stream_get_endp(circuit->rcv_stream) < ISIS_FIXED_HDR_LEN) {
+               zlog_err("PDU is too short to be IS-IS.");
+               return ISIS_ERROR;
+       }
 
-       if ((hdr->idrp != ISO10589_ISIS) && (hdr->idrp != ISO9542_ESIS)) {
-               zlog_err("Not an IS-IS or ES-IS packet IDRP=%02x", hdr->idrp);
+       uint8_t idrp = stream_getc(circuit->rcv_stream);
+       uint8_t length = stream_getc(circuit->rcv_stream);
+       uint8_t version1 = stream_getc(circuit->rcv_stream);
+       uint8_t id_len = stream_getc(circuit->rcv_stream);
+       uint8_t pdu_type = stream_getc(circuit->rcv_stream)
+                          & 0x1f; /* bits 6-8 are reserved */
+       uint8_t version2 = stream_getc(circuit->rcv_stream);
+       stream_forward_getp(circuit->rcv_stream, 1); /* reserved */
+       uint8_t max_area_addrs = stream_getc(circuit->rcv_stream);
+
+       if (idrp == ISO9542_ESIS) {
+               zlog_err("No support for ES-IS packet IDRP=%" PRIx8, idrp);
                return ISIS_ERROR;
        }
 
-       /* now we need to know if this is an ISO 9542 packet and
-        * take real good care of it, waaa!
-        */
-       if (hdr->idrp == ISO9542_ESIS) {
-               zlog_err("No support for ES-IS packet IDRP=%02x", hdr->idrp);
+       if (idrp != ISO10589_ISIS) {
+               zlog_err("Not an IS-IS packet IDRP=%" PRIx8, idrp);
                return ISIS_ERROR;
        }
-       stream_set_getp(circuit->rcv_stream, ISIS_FIXED_HDR_LEN);
 
-       /*
-        * and then process it
-        */
+       if (version1 != 1) {
+               zlog_warn("Unsupported ISIS version %" PRIu8, version1);
+               return ISIS_WARNING;
+       }
 
-       if (hdr->length < ISIS_MINIMUM_FIXED_HDR_LEN) {
-               zlog_err("Fixed header length = %d", hdr->length);
+       if (id_len != 0 && id_len != ISIS_SYS_ID_LEN) {
+               zlog_err(
+                       "IDFieldLengthMismatch: ID Length field in a received PDU  %" PRIu8
+                       ", while the parameter for this IS is %u",
+                       id_len, ISIS_SYS_ID_LEN);
                return ISIS_ERROR;
        }
 
-       if (hdr->version1 != 1) {
-               zlog_warn("Unsupported ISIS version %u", hdr->version1);
+       uint8_t expected_length;
+       if (pdu_size(pdu_type, &expected_length)) {
+               zlog_warn("Unsupported ISIS PDU %" PRIu8, pdu_type);
                return ISIS_WARNING;
        }
-       /* either 6 or 0 */
-       if ((hdr->id_len != 0) && (hdr->id_len != ISIS_SYS_ID_LEN)) {
+
+       if (length != expected_length) {
+               zlog_err("Exepected fixed header length = %" PRIu8
+                        " but got %" PRIu8,
+                        expected_length, length);
+               return ISIS_ERROR;
+       }
+
+       if (stream_get_endp(circuit->rcv_stream) < length) {
                zlog_err(
-                       "IDFieldLengthMismatch: ID Length field in a received PDU  %u, "
-                       "while the parameter for this IS is %u",
-                       hdr->id_len, ISIS_SYS_ID_LEN);
+                       "PDU is too short to contain fixed header of given PDU type.");
                return ISIS_ERROR;
        }
 
-       if (hdr->version2 != 1) {
-               zlog_warn("Unsupported ISIS version %u", hdr->version2);
+       if (version2 != 1) {
+               zlog_warn("Unsupported ISIS PDU version %" PRIu8, version2);
                return ISIS_WARNING;
        }
 
@@ -1951,16 +1995,15 @@ static int isis_handle_pdu(struct isis_circuit *circuit, u_char *ssnpa)
        }
 
        /* either 3 or 0 */
-       if ((hdr->max_area_addrs != 0)
-           && (hdr->max_area_addrs != isis->max_area_addrs)) {
+       if (max_area_addrs != 0 && max_area_addrs != isis->max_area_addrs) {
                zlog_err(
-                       "maximumAreaAddressesMismatch: maximumAreaAdresses in a "
-                       "received PDU %u while the parameter for this IS is %u",
-                       hdr->max_area_addrs, isis->max_area_addrs);
+                       "maximumAreaAddressesMismatch: maximumAreaAdresses in a received PDU %" PRIu8
+                       " while the parameter for this IS is %u",
+                       max_area_addrs, isis->max_area_addrs);
                return ISIS_ERROR;
        }
 
-       switch (hdr->pdu_type) {
+       switch (pdu_type) {
        case L1_LAN_HELLO:
                retval = process_lan_hello(ISIS_LEVEL1, circuit, ssnpa);
                break;
@@ -2025,68 +2068,28 @@ int isis_receive(struct thread *thread)
        return retval;
 }
 
-/* filling of the fixed isis header */
-void fill_fixed_hdr(struct isis_fixed_hdr *hdr, u_char pdu_type)
-{
-       memset(hdr, 0, sizeof(struct isis_fixed_hdr));
-
-       hdr->idrp = ISO10589_ISIS;
-
-       switch (pdu_type) {
-       case L1_LAN_HELLO:
-       case L2_LAN_HELLO:
-               hdr->length = ISIS_LANHELLO_HDRLEN;
-               break;
-       case P2P_HELLO:
-               hdr->length = ISIS_P2PHELLO_HDRLEN;
-               break;
-       case L1_LINK_STATE:
-       case L2_LINK_STATE:
-               hdr->length = ISIS_LSP_HDR_LEN;
-               break;
-       case L1_COMPLETE_SEQ_NUM:
-       case L2_COMPLETE_SEQ_NUM:
-               hdr->length = ISIS_CSNP_HDRLEN;
-               break;
-       case L1_PARTIAL_SEQ_NUM:
-       case L2_PARTIAL_SEQ_NUM:
-               hdr->length = ISIS_PSNP_HDRLEN;
-               break;
-       default:
-               zlog_warn("fill_fixed_hdr(): unknown pdu type %d", pdu_type);
-               return;
-       }
-       hdr->length += ISIS_FIXED_HDR_LEN;
-       hdr->pdu_type = pdu_type;
-       hdr->version1 = 1;
-       hdr->id_len = 0; /* ISIS_SYS_ID_LEN -  0==6 */
-       hdr->version2 = 1;
-       hdr->max_area_addrs = 0; /* isis->max_area_addrs -  0==3 */
-}
-
 /*
  * SEND SIDE
  */
-static void fill_fixed_hdr_andstream(struct isis_fixed_hdr *hdr,
-                                    u_char pdu_type, struct stream *stream)
+void fill_fixed_hdr(uint8_t pdu_type, struct stream *stream)
 {
-       fill_fixed_hdr(hdr, pdu_type);
-
-       stream_putc(stream, hdr->idrp);
-       stream_putc(stream, hdr->length);
-       stream_putc(stream, hdr->version1);
-       stream_putc(stream, hdr->id_len);
-       stream_putc(stream, hdr->pdu_type);
-       stream_putc(stream, hdr->version2);
-       stream_putc(stream, hdr->reserved);
-       stream_putc(stream, hdr->max_area_addrs);
-
-       return;
+       uint8_t length;
+
+       if (pdu_size(pdu_type, &length))
+               assert(!"Unknown PDU Type");
+
+       stream_putc(stream, ISO10589_ISIS); /* IDRP */
+       stream_putc(stream, length);    /* Length of fixed header */
+       stream_putc(stream, 1); /* Version/Protocol ID Extension 1 */
+       stream_putc(stream, 0); /* ID Length, 0 => 6 */
+       stream_putc(stream, pdu_type);
+       stream_putc(stream, 1); /* Subversion */
+       stream_putc(stream, 0); /* Reserved */
+       stream_putc(stream, 0); /* Max Area Addresses 0 => 3 */
 }
 
 int send_hello(struct isis_circuit *circuit, int level)
 {
-       struct isis_fixed_hdr fixed_hdr;
        struct isis_lan_hello_hdr hello_hdr;
        struct isis_p2p_hello_hdr p2p_hello_hdr;
        unsigned char hmac_md5_hash[ISIS_AUTH_MD5_SIZE];
@@ -2104,16 +2107,14 @@ int send_hello(struct isis_circuit *circuit, int level)
 
        isis_circuit_stream(circuit, &circuit->snd_stream);
 
+       uint8_t pdu_type;
+
        if (circuit->circ_type == CIRCUIT_T_BROADCAST)
-               if (level == IS_LEVEL_1)
-                       fill_fixed_hdr_andstream(&fixed_hdr, L1_LAN_HELLO,
-                                                circuit->snd_stream);
-               else
-                       fill_fixed_hdr_andstream(&fixed_hdr, L2_LAN_HELLO,
-                                                circuit->snd_stream);
+               pdu_type = (level == IS_LEVEL_1) ? L1_LAN_HELLO : L2_LAN_HELLO;
        else
-               fill_fixed_hdr_andstream(&fixed_hdr, P2P_HELLO,
-                                        circuit->snd_stream);
+               pdu_type = P2P_HELLO;
+
+       fill_fixed_hdr(pdu_type, circuit->snd_stream);
 
        /*
         * Fill LAN Level 1 or 2 Hello PDU header
@@ -2369,22 +2370,18 @@ int send_p2p_hello(struct thread *thread)
 static int build_csnp(int level, u_char *start, u_char *stop, struct list *lsps,
                      struct isis_circuit *circuit)
 {
-       struct isis_fixed_hdr fixed_hdr;
        struct isis_passwd *passwd;
        unsigned long lenp;
        u_int16_t length;
        unsigned char hmac_md5_hash[ISIS_AUTH_MD5_SIZE];
        unsigned long auth_tlv_offset = 0;
        int retval = ISIS_OK;
+       uint8_t pdu_type = (level == IS_LEVEL_1) ? L1_COMPLETE_SEQ_NUM
+                                                : L2_COMPLETE_SEQ_NUM;
 
        isis_circuit_stream(circuit, &circuit->snd_stream);
 
-       if (level == IS_LEVEL_1)
-               fill_fixed_hdr_andstream(&fixed_hdr, L1_COMPLETE_SEQ_NUM,
-                                        circuit->snd_stream);
-       else
-               fill_fixed_hdr_andstream(&fixed_hdr, L2_COMPLETE_SEQ_NUM,
-                                        circuit->snd_stream);
+       fill_fixed_hdr(pdu_type, circuit->snd_stream);
 
        /*
         * Fill Level 1 or 2 Complete Sequence Numbers header
@@ -2682,7 +2679,6 @@ int send_l2_csnp(struct thread *thread)
 static int build_psnp(int level, struct isis_circuit *circuit,
                      struct list *lsps)
 {
-       struct isis_fixed_hdr fixed_hdr;
        unsigned long lenp;
        u_int16_t length;
        struct isis_lsp *lsp;
@@ -2691,15 +2687,12 @@ static int build_psnp(int level, struct isis_circuit *circuit,
        unsigned char hmac_md5_hash[ISIS_AUTH_MD5_SIZE];
        unsigned long auth_tlv_offset = 0;
        int retval = ISIS_OK;
+       uint8_t pdu_type =
+               (level == IS_LEVEL_1) ? L1_PARTIAL_SEQ_NUM : L2_PARTIAL_SEQ_NUM;
 
        isis_circuit_stream(circuit, &circuit->snd_stream);
 
-       if (level == IS_LEVEL_1)
-               fill_fixed_hdr_andstream(&fixed_hdr, L1_PARTIAL_SEQ_NUM,
-                                        circuit->snd_stream);
-       else
-               fill_fixed_hdr_andstream(&fixed_hdr, L2_PARTIAL_SEQ_NUM,
-                                        circuit->snd_stream);
+       fill_fixed_hdr(pdu_type, circuit->snd_stream);
 
        /*
         * Fill Level 1 or 2 Partial Sequence Numbers header
@@ -3033,18 +3026,12 @@ int ack_lsp(struct isis_link_state_hdr *hdr, struct isis_circuit *circuit,
        unsigned long lenp;
        int retval;
        u_int16_t length;
-       struct isis_fixed_hdr fixed_hdr;
+       uint8_t pdu_type =
+               (level == IS_LEVEL_1) ? L1_PARTIAL_SEQ_NUM : L2_PARTIAL_SEQ_NUM;
 
        isis_circuit_stream(circuit, &circuit->snd_stream);
 
-       //  fill_llc_hdr (stream);
-       if (level == IS_LEVEL_1)
-               fill_fixed_hdr_andstream(&fixed_hdr, L1_PARTIAL_SEQ_NUM,
-                                        circuit->snd_stream);
-       else
-               fill_fixed_hdr_andstream(&fixed_hdr, L2_PARTIAL_SEQ_NUM,
-                                        circuit->snd_stream);
-
+       fill_fixed_hdr(pdu_type, circuit->snd_stream);
 
        lenp = stream_get_endp(circuit->snd_stream);
        stream_putw(circuit->snd_stream, 0); /* PDU length  */

diff --git a/isisd/isis_pdu.h b/isisd/isis_pdu.h
index fa8006cda034af6e6176cb99df6717d58eff43f5..985fc56adfe25640cd0b18ac602cf454e35a9ff5 100644 (file)
--- a/isisd/isis_pdu.h
+++ b/isisd/isis_pdu.h
@@ -65,36 +65,6 @@ struct esis_fixed_hdr {
 #define ISH_PDU              4
 #define RD_PDU               5
 
-/*
- *                       IS to IS Fixed Header
- *  +-------+-------+-------+-------+-------+-------+-------+-------+
- *  |         Intradomain Routeing Protocol Discriminator           |
- *  +-------+-------+-------+-------+-------+-------+-------+-------+
- *  |                       Length Indicator                        |
- *  +-------+-------+-------+-------+-------+-------+-------+-------+
- *  |                  Version/Protocol ID extension                |
- *  +-------+-------+-------+-------+-------+-------+-------+-------+
- *  |   R   |   R   |   R   |              PDU Type                 |
- *  +-------+-------+-------+-------+-------+-------+-------+-------+
- *  |                            Version                            |
- *  +-------+-------+-------+-------+-------+-------+-------+-------+
- *  |                            Reserved                           |
- *  +-------+-------+-------+-------+-------+-------+-------+-------+
- *  |                       Maximum Area Addresses                  |
- *  +-------+-------+-------+-------+-------+-------+-------+-------+
- */
-
-struct isis_fixed_hdr {
-       u_char idrp;
-       u_char length;
-       u_char version1;
-       u_char id_len;
-       u_char pdu_type;
-       u_char version2;
-       u_char reserved;
-       u_char max_area_addrs;
-} __attribute__((packed));
-
 #define ISIS_FIXED_HDR_LEN 8
 
 /*
@@ -261,7 +231,7 @@ int send_l2_psnp(struct thread *thread);
 int send_lsp(struct thread *thread);
 int ack_lsp(struct isis_link_state_hdr *hdr, struct isis_circuit *circuit,
            int level);
-void fill_fixed_hdr(struct isis_fixed_hdr *hdr, u_char pdu_type);
+void fill_fixed_hdr(uint8_t pdu_type, struct stream *stream);
 int send_hello(struct isis_circuit *circuit, int level);
 
 #endif /* _ZEBRA_ISIS_PDU_H */