--- /dev/null
+/* polypath
+ * send/receive module for secnet
+ * for multi-route setups */
+
+#include "secnet.h"
+#include "util.h"
+#include "unaligned.h"
+#include "comm-common.h"
+
+#include <adns.h>
+#include <ctype.h>
+
+#ifdef CONFIG_IPV6
+
+static comm_sendmsg_fn polypath_sendmsg;
+
+struct interf {
+ char *name; /* from malloc */
+ struct udpsocks socks;
+ bool_t experienced_xmit_noaf[MAX_AF+1];
+ LIST_ENTRY(interf) entry;
+};
+
+struct polypath {
+ struct udpcommon uc;
+ int max_interfs;
+ const char *const *ifname_pats;
+ const char *const *monitor_command;
+ bool_t permit_loopback;
+ LIST_HEAD(,interf) interfs;
+ struct buffer_if lbuf;
+ int monitor_fd;
+ pid_t monitor_pid;
+};
+
+#define LG 0, st->uc.cc.cl.description, &st->uc.cc.loc
+
+static const char *const default_loopback_ifname_pats[] = {
+ "!lo", 0
+};
+static const char *const default_ifname_pats[] = {
+ "!tun*","!tap*","!sl*","!userv*", "*", 0
+};
+
+static const char *const default_monitor_command[] = {
+ 0
+};
+
+static const char *polypath_addr_to_string(void *commst,
+ const struct comm_addr *ca)
+{
+ static char sbuf[100];
+
+ snprintf(sbuf, sizeof(sbuf), "polypath:%s",
+ iaddr_to_string(&ca->ia));
+ return sbuf;
+}
+
+static bool_t ifname_search_pats(struct polypath *st, struct cloc loc,
+ const char *ifname, bool_t *want_io,
+ const char *const *pats) {
+ /* Returns True iff we found a list entry, in which case *want_io
+ * is set to the sense of that entry. Otherwise *want_io is set
+ * to the sense of the last entry, or unchanged if there were no pats. */
+ if (!pats)
+ return False;
+ const char *const *pati;
+ for (pati=pats; *pati; pati++) {
+ const char *pat=*pati;
+ if (*pat=='!') { *want_io=False; pat++; }
+ else if (*pat=='+') { *want_io=True; pat++; }
+ else if (*pat=='*' || isalnum((unsigned char)*pat)) { *want_io=True; }
+ else cfgfatal(loc,"polypath","invalid interface name pattern `%s'",pat);
+ int match=fnmatch(pat,ifname,0);
+ if (match==0) return True;
+ if (match!=FNM_NOMATCH)
+ cfgfatal(loc,"polypath","fnmatch failed! (pattern `%s')",pat);
+ }
+ return False;
+}
+
+static bool_t ifname_wanted(struct polypath *st, struct cloc loc,
+ const char *ifname) {
+ bool_t want=False; /* pretend an empty cfg ends with !<doesn'tmatch> */
+ if (ifname_search_pats(st,loc,ifname,&want, st->ifname_pats))
+ return want;
+ if (want) /* last pattern was positive, do not search default */
+ return False;
+ if (!st->permit_loopback &&
+ ifname_search_pats(st,loc,ifname,&want, default_loopback_ifname_pats))
+ return want;
+ if (ifname_search_pats(st,loc,ifname,&want, default_ifname_pats))
+ return want;
+ abort();
+}
+
+static int polypath_beforepoll(void *state, struct pollfd *fds, int *nfds_io,
+ int *timeout_io)
+{
+ struct polypath *st=state;
+ BEFOREPOLL_WANT_FDS(1);
+ fds[0].fd=st->monitor_fd;
+ fds[0].events=POLLIN;
+ return 0;
+}
+
+static void dump_ppml(struct polypath *st, const char *orgl)
+{
+#ifdef POLYPATH_DEBUG
+ struct interf *interf;
+ if (orgl)
+ lg_perror(LG,M_DEBUG,0, "polypath monitor line `%s'",orgl);
+ LIST_FOREACH(interf, &st->interfs, entry) {
+ lg_perror(LG,M_DEBUG,0, " polypath interface `%s', nsocks=%d",
+ interf->name, interf->socks.n_socks);
+ int i;
+ for (i=0; i<interf->socks.n_socks; i++) {
+ struct udpsock *us=&interf->socks.socks[i];
+ lg_perror(LG,M_DEBUG,0, " polypath sock fd=%d addr=%s",
+ us->fd, iaddr_to_string(&us->addr));
+ }
+ }
+#endif
+}
+
+static void bad(struct polypath *st, char *l, char *undospace,
+ const char *m, int ev)
+{
+ if (undospace)
+ *undospace=' ';
+ lg_perror(LG,M_WARNING,ev,
+ "error processing polypath state change: %s"
+ " (while processing `%s')",
+ m,l);
+}
+
+static inline bool_t matches32(uint32_t word, uint32_t prefix, int prefixlen)
+{
+ assert(prefixlen>0);
+ assert(prefixlen<=32);
+ uint32_t mask = ~(((uint32_t)1 << (32-prefixlen)) - 1);
+ assert(!(prefix & ~mask));
+ return (word & mask) == prefix;
+}
+
+static void polypath_process_monitor_line(struct polypath *st, char *orgl)
+{
+ struct interf *interf=0;
+ struct udpcommon *uc=&st->uc;
+ char *undospace=0;
+ char *l=orgl;
+ struct udpsock *us=0;
+
+ dump_ppml(st,orgl);
+
+#define BAD(m) do{ bad(st,orgl,undospace,m,0); goto out; }while(0)
+#define BADE(m,ev) do{ bad(st,orgl,undospace,m,ev); goto out; }while(0)
+
+ bool_t add;
+ int c=*l++;
+ if (c=='+') add=True;
+ else if (c=='-') add=False;
+ else BAD("bad +/-");
+
+ int proto;
+ c=*l++;
+ if (c=='4') proto=AF_INET;
+ else if (c=='6') proto=AF_INET6;
+ else BAD("bad proto");
+
+ char *space=strchr(l,' ');
+ if (!space) BAD("no first space");
+ const char *ifname=space+1;
+
+ space=strchr(ifname,' ');
+ if (!space) BAD("no second space");
+ const char *ifaddr=space+1;
+ *space=0;
+ undospace=space;
+
+ union iaddr ia;
+ FILLZERO(ia);
+ socklen_t salen=sizeof(ia);
+ int r=adns_text2addr(ifaddr,uc->port, adns_qf_addrlit_ipv4_quadonly,
+ &ia.sa, &salen);
+ assert(r!=ENOSPC);
+ if (r) BADE("adns_text2addr",r);
+ if (ia.sa.sa_family!=proto) BAD("address family mismatch");
+
+#define DONT(m) do{ \
+ if (add) \
+ lg_perror(LG,M_INFO,0,"ignoring %s [%s]: %s",ifname,ifaddr,m); \
+ goto out; \
+ }while(0)
+
+ if (!ifname_wanted(st,st->uc.cc.loc,ifname))
+ DONT("unwanted interface name");
+
+ switch (ia.sa.sa_family) {
+ case AF_INET6: {
+ const struct in6_addr *i6=&ia.sin6.sin6_addr;
+#define DONTKIND(X,m) \
+ if (IN6_IS_ADDR_##X(i6)) DONT("IPv6 address is " m)
+ DONTKIND(UNSPECIFIED, "unspecified");
+ DONTKIND(MULTICAST , "multicast" );
+ DONTKIND(LINKLOCAL , "link local" );
+ DONTKIND(SITELOCAL , "site local" );
+ DONTKIND(V4MAPPED , "v4-mapped" );
+ if (!st->permit_loopback)
+ DONTKIND(LOOPBACK , "loopback" );
+#undef DONTKIND
+#define DONTMASK(w7x,w6x,prefixlen,m) \
+ if (matches32(get_uint32(i6->s6_addr), \
+ ((uint32_t)0x##w7x << 16) | (uint32_t)0x##w6x, \
+ prefixlen)) \
+ DONT("IPv6 address is " m)
+ DONTMASK( 100, 0, 8, "Discard-Only (RFC6666)");
+ DONTMASK(2001, 0, 23, "in IETF protocol block (RFC2928)");
+#undef DONTMASK
+ break;
+ }
+ case AF_INET: {
+ const uint32_t i4=htonl(ia.sin.sin_addr.s_addr);
+ if (i4==INADDR_ANY) DONT("IPv4 address is any/unspecified");
+ if (i4==INADDR_BROADCAST) DONT("IPv4 address is all hosts broadcast");
+#define DONTMASK(b3,b2,b1,b0,prefixlen,m) do{ \
+ const uint8_t prefixbytes[4] = { (b3),(b2),(b1),(b0) }; \
+ if (matches32(i4,get_uint32(prefixbytes),prefixlen)) \
+ DONT("IPv4 address is " m); \
+ }while(0)
+ DONTMASK(169,254,0,0, 16, "link local");
+ DONTMASK(224, 0,0,0, 4, "multicast");
+ DONTMASK(192, 0,0,0, 24, "in IETF protocol block (RFC6890)");
+ DONTMASK(240, 0,0,0, 4, "in reserved addressing block (RFC1112)");
+ if (!st->permit_loopback)
+ DONTMASK(127, 0,0,0, 8, "loopback");
+#undef DONTMASK
+ break;
+ }
+ default:
+ abort();
+ }
+
+ /* OK, process it */
+ int n_ifs=0;
+ LIST_FOREACH(interf,&st->interfs,entry) {
+ if (!strcmp(interf->name,ifname))
+ goto found_interf;
+ n_ifs++;
+ }
+ /* not found */
+ if (n_ifs==st->max_interfs) BAD("too many interfaces");
+ interf=malloc(sizeof(*interf));
+ if (!interf) BADE("malloc for new interface",errno);
+ interf->name=0;
+ interf->socks.n_socks=0;
+ FILLZERO(interf->experienced_xmit_noaf);
+ LIST_INSERT_HEAD(&st->interfs,interf,entry);
+ udp_socks_register(&st->uc,&interf->socks);
+ interf->name=strdup(ifname);
+ if (!interf->name) BADE("strdup interface name",errno);
+ found_interf:
+
+ if (add) {
+ if (interf->socks.n_socks == UDP_MAX_SOCKETS)
+ BAD("too many addresses on this interface");
+ struct udpsock *us=&interf->socks.socks[interf->socks.n_socks];
+ us->fd=-1;
+ COPY_OBJ(us->addr,ia);
+ bool_t ok=udp_make_socket(&st->uc,us,M_WARNING);
+ if (!ok) BAD("unable to set up socket");
+ r=setsockopt(us->fd,SOL_SOCKET,SO_BINDTODEVICE,
+ ifname,strlen(ifname)+1);
+ if (r) BADE("setsockopt(,,SO_BINDTODEVICE,)",errno);
+ interf->socks.n_socks++;
+ us=0; /* do not destroy this socket during `out' */
+ lg_perror(LG,M_INFO,0,"using %s %s",ifname,ifaddr);
+ } else {
+ int i;
+ for (i=0; i<interf->socks.n_socks; i++)
+ if (!memcmp(&interf->socks.socks[i].addr,&ia,sizeof(ia)))
+ goto address_remove_found;
+ BAD("address to remove not found");
+ address_remove_found:
+ lg_perror(LG,M_INFO,0,"removed %s %s",ifname,ifaddr);
+ udp_destroy_socket(&st->uc,&interf->socks.socks[i]);
+ interf->socks.socks[i]=
+ interf->socks.socks[--interf->socks.n_socks];
+ }
+
+ out:
+ if (us)
+ udp_destroy_socket(uc,us);
+ if (interf && !interf->socks.n_socks) {
+ udp_socks_deregister(&st->uc,&interf->socks);
+ LIST_REMOVE(interf,entry);
+ free(interf->name);
+ free(interf);
+ }
+
+ dump_ppml(st,0);
+
+#undef BAD
+#undef BADE
+#undef DONT
+}
+
+static void polypath_afterpoll(void *state, struct pollfd *fds, int nfds)
+{
+ struct polypath *st=state;
+ enum async_linebuf_result alr;
+ const char *emsg;
+ int status;
+
+ if (nfds<1) return;
+
+ while ((alr=async_linebuf_read(fds,&st->lbuf,&emsg)) == async_linebuf_ok)
+ polypath_process_monitor_line(st,st->lbuf.base);
+
+ if (alr==async_linebuf_nothing)
+ return;
+
+ assert(st->monitor_pid);
+
+ pid_t gotpid=waitpid(st->monitor_pid,&status,WNOHANG);
+ if (gotpid==st->monitor_pid) {
+ st->monitor_pid=0;
+ lg_exitstatus(LG,M_FATAL,status,"interface monitor");
+ } else if (gotpid<0)
+ lg_perror(LG,M_ERR,errno,"unable to reap interface monitor");
+ else
+ assert(gotpid==0);
+
+ if (alr==async_linebuf_eof)
+ lg_perror(LG,M_FATAL,0,"unexpected EOF from interface monitor");
+ else
+ lg_perror(LG,M_FATAL,0,"bad output from interface monitor: %s",emsg);
+
+ assert(!"not reached");
+}
+
+/* Actual udp packet sending work */
+static bool_t polypath_sendmsg(void *commst, struct buffer_if *buf,
+ const struct comm_addr *dest)
+{
+ struct polypath *st=commst;
+ struct interf *interf;
+ bool_t allreasonable=True;
+ int af=dest->ia.sa.sa_family;
+
+ LIST_FOREACH(interf,&st->interfs,entry) {
+ int i;
+ bool_t attempted=False, reasonable=False;
+ for (i=0; i<interf->socks.n_socks; i++) {
+ struct udpsock *us=&interf->socks.socks[i];
+ if (af != us->addr.sa.sa_family)
+ continue;
+ attempted=True;
+ int r=sendto(us->fd,buf->start,buf->size,
+ 0,&dest->ia.sa,iaddr_socklen(&dest->ia));
+ udp_sock_experienced(0,&st->uc, interf->name,us,
+ 1,af, r,errno);
+ if (r>=0) {
+ reasonable=True;
+ break;
+ }
+ if (!(errno==EAFNOSUPPORT || errno==ENETUNREACH))
+ reasonable=True;
+ lg_perror(LG,M_DEBUG,errno,"%s [%s] xmit %"PRIu32" bytes to %s",
+ interf->name,iaddr_to_string(&us->addr),
+ buf->size,iaddr_to_string(&dest->ia));
+ }
+ if (!attempted)
+ if (!interf->experienced_xmit_noaf[af]++)
+ lg_perror(LG,M_WARNING,0,
+ "%s has no suitable address to transmit %s",
+ interf->name, af_name(af));
+ allreasonable *= reasonable;
+ }
+ return allreasonable;
+}
+
+static void polypath_phase_startmonitor(void *sst, uint32_t newphase)
+{
+ struct polypath *st=sst;
+ int pfds[2];
+
+ assert(!st->monitor_pid);
+ assert(st->monitor_fd<0);
+
+ pipe_cloexec(pfds);
+
+ pid_t pid=fork();
+ if (!pid) {
+ afterfork();
+ dup2(pfds[1],1);
+ execvp(st->monitor_command[0],(char**)st->monitor_command);
+ fprintf(stderr,"secnet: cannot execute %s: %s\n",
+ st->monitor_command[0], strerror(errno));
+ exit(-1);
+ }
+ if (pid<0)
+ fatal_perror("%s: failed to fork for interface monitor",
+ st->uc.cc.cl.description);
+
+ close(pfds[1]);
+ st->monitor_pid=pid;
+ st->monitor_fd=pfds[0];
+ setnonblock(st->monitor_fd);
+
+ register_for_poll(st,polypath_beforepoll,polypath_afterpoll,"polypath");
+}
+
+static void polypath_phase_shutdown(void *sst, uint32_t newphase)
+{
+ struct polypath *st=sst;
+ if (st->monitor_pid) {
+ assert(st->monitor_pid>0);
+ kill(st->monitor_pid,SIGTERM);
+ }
+}
+
+static list_t *polypath_apply(closure_t *self, struct cloc loc,
+ dict_t *context, list_t *args)
+{
+ struct polypath *st;
+
+ COMM_APPLY(st,&st->uc.cc,polypath_,"polypath",loc);
+ COMM_APPLY_STANDARD(st,&st->uc.cc,"polypath",args);
+ UDP_APPLY_STANDARD(st,&st->uc,"polypath");
+
+ struct udpcommon *uc=&st->uc;
+ struct commcommon *cc=&uc->cc;
+
+ st->max_interfs=dict_read_number(d,"max-interfaces",False,"polypath",loc,3);
+
+ st->ifname_pats=dict_read_string_array(d,"interfaces",False,"polypath",
+ cc->loc,0);
+ st->permit_loopback=0; /* ifname_wanted reads this */
+ ifname_wanted(st,st->uc.cc.loc," "); /* try to check each pattern */
+
+ st->monitor_command=dict_read_string_array(d,"monitor-command",False,
+ "polypath",cc->loc, default_monitor_command);
+ if (!st->monitor_command[0])
+ cfgfatal(loc,"polypath","no polypath interface monitor-command"
+ " (polypath unsupported on this platform?)\n");
+
+ st->permit_loopback=dict_read_bool(d,"permit-loopback",False,
+ "polypath",cc->loc,False);
+
+ LIST_INIT(&st->interfs);
+ buffer_new(&st->lbuf,ADNS_ADDR2TEXT_BUFLEN+100);
+ BUF_ALLOC(&st->lbuf,"polypath lbuf");
+
+ st->monitor_fd=-1;
+ st->monitor_pid=0;
+
+ add_hook(PHASE_RUN, polypath_phase_startmonitor,st);
+ add_hook(PHASE_SHUTDOWN, polypath_phase_shutdown, st);
+
+ return new_closure(&cc->cl);
+}
+
+#endif /* CONFIG_IPV6 */
+
+void polypath_module(dict_t *dict)
+{
+#ifdef CONFIG_IPV6
+ add_closure(dict,"polypath",polypath_apply);
+#endif /* CONFIG_IPV6 */
+}
~ianmdlvl / secnet.git / commitdiff