diff options
Diffstat (limited to 'lib/erl_interface/src/connect/ei_connect.c')
| -rw-r--r-- | lib/erl_interface/src/connect/ei_connect.c | 74 |
1 files changed, 67 insertions, 7 deletions
diff --git a/lib/erl_interface/src/connect/ei_connect.c b/lib/erl_interface/src/connect/ei_connect.c index c193fd804a..5c01223e3d 100644 --- a/lib/erl_interface/src/connect/ei_connect.c +++ b/lib/erl_interface/src/connect/ei_connect.c @@ -1,7 +1,7 @@ /* * %CopyrightBegin% * - * Copyright Ericsson AB 2000-2016. All Rights Reserved. + * Copyright Ericsson AB 2000-2017. All Rights Reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. @@ -497,7 +497,8 @@ int ei_connect_init(ei_cnode* ec, const char* this_node_name, } #endif /* _REENTRANT */ - if (gethostname(thishostname, EI_MAXHOSTNAMELEN) == -1) { + /* gethostname requires len to be max(hostname) + 1 */ + if (gethostname(thishostname, EI_MAXHOSTNAMELEN+1) == -1) { #ifdef __WIN32__ EI_TRACE_ERR1("ei_connect_init","Failed to get host name: %d", WSAGetLastError()); @@ -582,6 +583,54 @@ static int cnct(uint16 port, struct in_addr *ip_addr, int addr_len, unsigned ms) return s; } /* cnct */ + +/* + * Same as ei_gethostbyname_r, but also handles ERANGE error + * and may allocate larger buffer with malloc. + */ +static +struct hostent *dyn_gethostbyname_r(const char *name, + struct hostent *hostp, + char **buffer_p, + int buflen, + int *h_errnop) +{ + char* buf = *buffer_p; + struct hostent *hp; + + while (1) { + hp = ei_gethostbyname_r(name, hostp, buf, buflen, h_errnop); + if (hp) { + *buffer_p = buf; + break; + } + + if (*h_errnop != ERANGE) { + if (buf != *buffer_p) + free(buf); + break; + } + + buflen *= 2; + if (buf == *buffer_p) + buf = malloc(buflen); + else { + char* buf2 = realloc(buf, buflen); + if (buf2) + buf = buf2; + else { + free(buf); + buf = NULL; + } + } + if (!buf) { + *h_errnop = ENOMEM; + break; + } + } + return hp; +} + /* * Set up a connection to a given Node, and * interchange hand shake messages with it. @@ -596,8 +645,10 @@ int ei_connect_tmo(ei_cnode* ec, char *nodename, unsigned ms) /* these are needed for the call to gethostbyname_r */ struct hostent host; char buffer[1024]; + char *buf = buffer; int ei_h_errno; #endif /* !win32 */ + int res; /* extract the host and alive parts from nodename */ if (!(hostname = strchr(nodename,'@'))) { @@ -610,10 +661,11 @@ int ei_connect_tmo(ei_cnode* ec, char *nodename, unsigned ms) } #ifndef __WIN32__ - hp = ei_gethostbyname_r(hostname,&host,buffer,1024,&ei_h_errno); + hp = dyn_gethostbyname_r(hostname,&host,&buf,sizeof(buffer),&ei_h_errno); if (hp == NULL) { char thishostname[EI_MAXHOSTNAMELEN+1]; - if (gethostname(thishostname,EI_MAXHOSTNAMELEN) < 0) { + /* gethostname requies len to be max(hostname) + 1*/ + if (gethostname(thishostname,EI_MAXHOSTNAMELEN+1) < 0) { EI_TRACE_ERR0("ei_connect_tmo", "Failed to get name of this host"); erl_errno = EHOSTUNREACH; @@ -625,7 +677,7 @@ int ei_connect_tmo(ei_cnode* ec, char *nodename, unsigned ms) } if (strcmp(hostname,thishostname) == 0) /* Both nodes on same standalone host, use loopback */ - hp = ei_gethostbyname_r("localhost",&host,buffer,1024,&ei_h_errno); + hp = dyn_gethostbyname_r("localhost",&host,&buf,sizeof(buffer),&ei_h_errno); if (hp == NULL) { EI_TRACE_ERR2("ei_connect", "Can't find host for %s: %d\n",nodename,ei_h_errno); @@ -636,7 +688,8 @@ int ei_connect_tmo(ei_cnode* ec, char *nodename, unsigned ms) #else /* __WIN32__ */ if ((hp = ei_gethostbyname(hostname)) == NULL) { char thishostname[EI_MAXHOSTNAMELEN+1]; - if (gethostname(thishostname,EI_MAXHOSTNAMELEN) < 0) { + /* gethostname requires len to be max(hostname) + 1 */ + if (gethostname(thishostname,EI_MAXHOSTNAMELEN+1) < 0) { EI_TRACE_ERR1("ei_connect_tmo", "Failed to get name of this host: %d", WSAGetLastError()); @@ -660,7 +713,14 @@ int ei_connect_tmo(ei_cnode* ec, char *nodename, unsigned ms) } } #endif /* win32 */ - return ei_xconnect_tmo(ec, (Erl_IpAddr) *hp->h_addr_list, alivename, ms); + + res = ei_xconnect_tmo(ec, (Erl_IpAddr) *hp->h_addr_list, alivename, ms); + +#ifndef __WIN32__ + if (buf != buffer) + free(buf); +#endif + return res; } /* ei_connect */ int ei_connect(ei_cnode* ec, char *nodename) |