From 7ed55a412f9c9aeb941cea7e74d3003b95593639 Mon Sep 17 00:00:00 2001 From: Amritha Nambiar Date: Mon, 24 Aug 2015 16:40:14 -0700 Subject: [PATCH] isisd: Attached-bit in LSP header MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Set/reset attached-bit in LSP header: This patch provides support for set/reset attached_bit in the LSP header. In IS-IS networks, routing inter-area traffic from L1 areas is accomplished by sending the traffic to the nearest L1/L2 router. A L1/L2 router identifies itself by setting an attach-bit (ATT-bit) in its (LSP). The ATT-bit in LSP can be changed using the set-attached-bit or no-set-attached-bit commands (similar to ‘set-overload-bit’ and 'no set-overload-bit’) using telnet terminal in router configuration mode. Steps: enable configure terminal router isis set-attached-bit V2: Removed looping through area list as this well set the bit for all areas in the list. This implementation now looks exactly like the current overload bit implementation. Signed-off-by: Amritha Nambiar --- isisd/isis_lsp.c | 33 ++++++++++++++++++++++----------- isisd/isisd.c | 36 ++++++++++++++++++++++++++++++++++++ isisd/isisd.h | 2 ++ 3 files changed, 60 insertions(+), 11 deletions(-) diff --git a/isisd/isis_lsp.c b/isisd/isis_lsp.c index 2482b126c8..452a8a678f 100644 --- a/isisd/isis_lsp.c +++ b/isisd/isis_lsp.c @@ -442,7 +442,7 @@ lsp_seqnum_update (struct isis_lsp *lsp0) } static u_int8_t -lsp_bits_generate (int level, int overload_bit) +lsp_bits_generate (int level, int overload_bit, int attached_bit) { u_int8_t lsp_bits = 0; if (level == IS_LEVEL_1) @@ -451,6 +451,8 @@ lsp_bits_generate (int level, int overload_bit) lsp_bits = IS_LEVEL_1_AND_2; if (overload_bit) lsp_bits |= overload_bit; + if (attached_bit) + lsp_bits |= attached_bit; return lsp_bits; } @@ -1130,7 +1132,8 @@ lsp_next_frag (u_char frag_num, struct isis_lsp *lsp0, struct isis_area *area, return lsp; } lsp = lsp_new (frag_id, ntohs(lsp0->lsp_header->rem_lifetime), 0, - lsp_bits_generate (level, area->overload_bit), 0, level); + lsp_bits_generate (level, area->overload_bit, + area->attached_bit), 0, level); lsp->area = area; lsp->own_lsp = 1; lsp_insert (lsp, area->lspdb[level - 1]); @@ -1591,7 +1594,8 @@ lsp_generate (struct isis_area *area, int level) } rem_lifetime = lsp_rem_lifetime (area, level); newlsp = lsp_new (lspid, rem_lifetime, seq_num, - area->is_type | area->overload_bit, 0, level); + area->is_type | area->overload_bit | area->attached_bit, + 0, level); newlsp->area = area; newlsp->own_lsp = 1; @@ -1658,7 +1662,8 @@ lsp_regenerate (struct isis_area *area, int level) lsp_clear_data (lsp); lsp_build (lsp, area); - lsp->lsp_header->lsp_bits = lsp_bits_generate (level, area->overload_bit); + lsp->lsp_header->lsp_bits = lsp_bits_generate (level, area->overload_bit, + area->attached_bit); rem_lifetime = lsp_rem_lifetime (area, level); lsp->lsp_header->rem_lifetime = htons (rem_lifetime); lsp_seqnum_update (lsp); @@ -1668,7 +1673,8 @@ lsp_regenerate (struct isis_area *area, int level) for (ALL_LIST_ELEMENTS_RO (lsp->lspu.frags, node, frag)) { frag->lsp_header->lsp_bits = lsp_bits_generate (level, - area->overload_bit); + area->overload_bit, + area->attached_bit); /* Set the lifetime values of all the fragments to the same value, * so that no fragment expires before the lsp is refreshed. */ @@ -1829,7 +1835,8 @@ lsp_build_pseudo (struct isis_lsp *lsp, struct isis_circuit *circuit, lsp->level = level; /* RFC3787 section 4 SHOULD not set overload bit in pseudo LSPs */ - lsp->lsp_header->lsp_bits = lsp_bits_generate (level, 0); + lsp->lsp_header->lsp_bits = lsp_bits_generate (level, 0, + circuit->area->attached_bit); /* * add self to IS neighbours @@ -1959,7 +1966,9 @@ lsp_generate_pseudo (struct isis_circuit *circuit, int level) rem_lifetime = lsp_rem_lifetime (circuit->area, level); /* RFC3787 section 4 SHOULD not set overload bit in pseudo LSPs */ - lsp = lsp_new (lsp_id, rem_lifetime, 1, circuit->area->is_type, 0, level); + lsp = lsp_new (lsp_id, rem_lifetime, 1, + circuit->area->is_type | circuit->area->attached_bit, + 0, level); lsp->area = circuit->area; lsp_build_pseudo (lsp, circuit, level); @@ -2025,7 +2034,8 @@ lsp_regenerate_pseudo (struct isis_circuit *circuit, int level) lsp_build_pseudo (lsp, circuit, level); /* RFC3787 section 4 SHOULD not set overload bit in pseudo LSPs */ - lsp->lsp_header->lsp_bits = lsp_bits_generate (level, 0); + lsp->lsp_header->lsp_bits = lsp_bits_generate (level, 0, + circuit->area->attached_bit); rem_lifetime = lsp_rem_lifetime (circuit->area, level); lsp->lsp_header->rem_lifetime = htons (rem_lifetime); lsp_inc_seqnum (lsp, 0); @@ -2429,7 +2439,8 @@ top_lsp_refresh (struct thread *thread) IS_LEVEL_1); lsp->lsp_header->lsp_bits = lsp_bits_generate (lsp->level, - lsp->area->overload_bit); + lsp->area->overload_bit, + lsp->area->attached_bit); rem_lifetime = lsp_rem_lifetime (lsp->area, IS_LEVEL_1); lsp->lsp_header->rem_lifetime = htons (rem_lifetime); @@ -2468,8 +2479,8 @@ generate_topology_lsps (struct isis_area *area) lspid[ISIS_SYS_ID_LEN - 2] = ((i >> 8) & 0xFF); rem_lifetime = lsp_rem_lifetime (area, IS_LEVEL_1); - lsp = lsp_new (lspid, rem_lifetime, 1, IS_LEVEL_1 | area->overload_bit, - 0, 1); + lsp = lsp_new (lspid, rem_lifetime, 1, IS_LEVEL_1 | area->overload_bit + | area->attached_bit, 0, 1); if (!lsp) return; lsp->area = area; diff --git a/isisd/isisd.c b/isisd/isisd.c index 5c90764855..d786f402a0 100644 --- a/isisd/isisd.c +++ b/isisd/isisd.c @@ -2171,6 +2171,39 @@ DEFUN (no_set_overload_bit, return CMD_SUCCESS; } +DEFUN (set_attached_bit, + set_attached_bit_cmd, + "set-attached-bit", + "Set attached bit to identify as L1/L2 router for inter-area traffic\n" + "Set attached bit\n") +{ + struct isis_area *area; + + area = vty->index; + assert (area); + + area->attached_bit = LSPBIT_ATT; + lsp_regenerate_schedule (area, IS_LEVEL_1 | IS_LEVEL_2, 1); + + return CMD_SUCCESS; +} + +DEFUN (no_set_attached_bit, + no_set_attached_bit_cmd, + "no set-attached-bit", + "Reset attached bit\n") +{ + struct isis_area *area; + + area = vty->index; + assert (area); + + area->attached_bit = 0; + lsp_regenerate_schedule (area, IS_LEVEL_1 | IS_LEVEL_2, 1); + + return CMD_SUCCESS; +} + DEFUN (dynamic_hostname, dynamic_hostname_cmd, "hostname dynamic", @@ -3246,6 +3279,9 @@ isis_init () install_element (ISIS_NODE, &set_overload_bit_cmd); install_element (ISIS_NODE, &no_set_overload_bit_cmd); + install_element (ISIS_NODE, &set_attached_bit_cmd); + install_element (ISIS_NODE, &no_set_attached_bit_cmd); + install_element (ISIS_NODE, &dynamic_hostname_cmd); install_element (ISIS_NODE, &no_dynamic_hostname_cmd); diff --git a/isisd/isisd.h b/isisd/isisd.h index 5038d317bb..efebed9ce8 100644 --- a/isisd/isisd.h +++ b/isisd/isisd.h @@ -118,6 +118,8 @@ struct isis_area char is_type; /* level-1 level-1-2 or level-2-only */ /* are we overloaded? */ char overload_bit; + /* L1/L2 router identifier for inter-area traffic */ + char attached_bit; u_int16_t lsp_refresh[ISIS_LEVELS]; /* minimum time allowed before lsp retransmission */ u_int16_t lsp_gen_interval[ISIS_LEVELS]; -- 2.39.5