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author | Sverker Eriksson <[email protected]> | 2019-03-20 15:42:34 +0100 |
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committer | Sverker Eriksson <[email protected]> | 2019-03-22 19:40:36 +0100 |
commit | bd8f6106d44a58c261920eef72842bb3bc5a4968 (patch) | |
tree | 7472e2c80a2ee885cfcf767b0cb541a3417c0fd6 /erts/epmd/src/epmd_srv.c | |
parent | e2cf4a8a4b03b9f430ba228276c3b2629159e832 (diff) | |
download | otp-bd8f6106d44a58c261920eef72842bb3bc5a4968.tar.gz otp-bd8f6106d44a58c261920eef72842bb3bc5a4968.tar.bz2 otp-bd8f6106d44a58c261920eef72842bb3bc5a4968.zip |
epmd: Support 32-bit creation values in local node
* Increase distribution version from 5 to 6
* Introduce new ALIVE2_X_RESP with 32-bit creation
as reply to ALIVE2_REQ when sender dist version >= 6
* Still reply old ALIVE2_RESP with tiny creation 1..3
if sender dist version < 6.
Diffstat (limited to 'erts/epmd/src/epmd_srv.c')
-rw-r--r-- | erts/epmd/src/epmd_srv.c | 87 |
1 files changed, 49 insertions, 38 deletions
diff --git a/erts/epmd/src/epmd_srv.c b/erts/epmd/src/epmd_srv.c index 1f2326d241..633ec71e5f 100644 --- a/erts/epmd/src/epmd_srv.c +++ b/erts/epmd/src/epmd_srv.c @@ -665,6 +665,21 @@ static int do_accept(EpmdVars *g,int listensock) return conn_open(g,msgsock); } +static void bump_creation(Node* node) +{ + if (++node->cr_counter == 0) + node->cr_counter = 1; +} +static unsigned int get_creation(Node* node) +{ + if (node->highvsn >= 6) { + return node->cr_counter; /* 1..(2^32-1)*/ + } + else { + return (node->cr_counter - 1) % 3 + 1; /* 1..3 */ + } +} + /* buf is actually one byte larger than bsize, giving place for null termination */ static void do_request(g, fd, s, buf, bsize) @@ -706,8 +721,10 @@ static void do_request(g, fd, s, buf, bsize) unsigned char protocol; unsigned short highvsn; unsigned short lowvsn; + unsigned int creation; int namelen; int extralen; + int replylen; char *name; char *extra; eport = get_int16(&buf[1]); @@ -737,15 +754,20 @@ static void do_request(g, fd, s, buf, bsize) extra = &buf[11+namelen+2]; extra[extralen]='\000'; - wbuf[0] = EPMD_ALIVE2_RESP; - if ((node = node_reg2(g, namelen, name, fd, eport, nodetype, protocol, - highvsn, lowvsn, extralen, extra)) == NULL) { - wbuf[1] = 1; /* error */ - put_int16(99, wbuf+2); - } else { - wbuf[1] = 0; /* ok */ - put_int16(node->creation, wbuf+2); - } + node = node_reg2(g, namelen, name, fd, eport, nodetype, protocol, + highvsn, lowvsn, extralen, extra); + creation = node ? get_creation(node) : 99; + wbuf[1] = node ? 0 : 1; /* ok | error */ + if (highvsn >= 6) { + wbuf[0] = EPMD_ALIVE2_X_RESP; + put_int32(creation, wbuf+2); + replylen = 6; + } + else { + wbuf[0] = EPMD_ALIVE2_RESP; + put_int16(creation, wbuf+2); + replylen = 4; + } if (!reply(g, fd, wbuf, replylen)) { @@ -1200,8 +1222,8 @@ static int node_unreg(EpmdVars *g,char *name) for (; node; prev = &node->next, node = node->next) if (is_same_str(node->symname, name)) { - dbg_tty_printf(g,1,"unregistering '%s:%d', port %d", - node->symname, node->creation, node->port); + dbg_tty_printf(g,1,"unregistering '%s:%u', port %d", + node->symname, get_creation(node), node->port); *prev = node->next; /* Link out from "reg" list */ @@ -1235,8 +1257,8 @@ static int node_unreg_sock(EpmdVars *g,int fd) for (; node; prev = &node->next, node = node->next) if (node->fd == fd) { - dbg_tty_printf(g,1,"unregistering '%s:%d', port %d", - node->symname, node->creation, node->port); + dbg_tty_printf(g,1,"unregistering '%s:%u', port %d", + node->symname, get_creation(node), node->port); *prev = node->next; /* Link out from "reg" list */ @@ -1264,19 +1286,8 @@ static int node_unreg_sock(EpmdVars *g,int fd) } /* - * Finding a node slot and a (name,creation) name is a bit tricky. - * We try in order - * - * 1. If the name was used before and we can reuse that slot but use - * a new "creation" digit in the range 1..3. - * - * 2. We try to find a new unused slot. - * - * 3. We try to use an used slot this isn't used any longer. - * FIXME: The criteria for *what* slot to steal should be improved. - * Perhaps use the oldest or something. + * Register a new node */ - static Node *node_reg2(EpmdVars *g, int namelen, char* name, @@ -1346,7 +1357,7 @@ static Node *node_reg2(EpmdVars *g, } /* Try to find the name in the used queue so that we - can change "creation" number 1..3 */ + can change "creation" number */ prev = NULL; @@ -1375,9 +1386,8 @@ static Node *node_reg2(EpmdVars *g, g->nodes.unreg_count--; - /* When reusing we change the "creation" number 1..3 */ - - node->creation = node->creation % 3 + 1; + /* When reusing we change the "creation" number */ + bump_creation(node); break; } @@ -1404,7 +1414,8 @@ static Node *node_reg2(EpmdVars *g, exit(1); } - node->creation = (current_time(g) % 3) + 1; /* "random" 1-3 */ + node->cr_counter = current_time(g); /* "random" */ + bump_creation(node); } } @@ -1423,11 +1434,11 @@ static Node *node_reg2(EpmdVars *g, select_fd_set(g, fd); if (highvsn == 0) { - dbg_tty_printf(g,1,"registering '%s:%d', port %d", - node->symname, node->creation, node->port); + dbg_tty_printf(g,1,"registering '%s:%u', port %d", + node->symname, get_creation(node), node->port); } else { - dbg_tty_printf(g,1,"registering '%s:%d', port %d", - node->symname, node->creation, node->port); + dbg_tty_printf(g,1,"registering '%s:%u', port %d", + node->symname, get_creation(node), node->port); dbg_tty_printf(g,1,"type %d proto %d highvsn %d lowvsn %d", nodetype, protocol, highvsn, lowvsn); } @@ -1561,8 +1572,8 @@ static void print_names(EpmdVars *g) for (node = g->nodes.reg; node; node = node->next) { - fprintf(stderr,"***** active name \"%s#%d\" at port %d, fd = %d\r\n", - node->symname, node->creation, node->port, node->fd); + fprintf(stderr,"***** active name \"%s#%u\" at port %d, fd = %d\r\n", + node->symname, get_creation(node), node->port, node->fd); count ++; } @@ -1572,8 +1583,8 @@ static void print_names(EpmdVars *g) for (node = g->nodes.unreg; node; node = node->next) { - fprintf(stderr,"***** old/unused name \"%s#%d\"\r\n", - node->symname, node->creation); + fprintf(stderr,"***** old/unused name \"%s#%u\"\r\n", + node->symname, get_creation(node)); count ++; } |