From de6f14800675cd0401106876da81da7618de71c6 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Thu, 28 Feb 2013 12:20:06 +0100 Subject: [PATCH] nc_bloaty: support -ll and -lk. Closes 2245 Signed-off-by: Denys Vlasenko --- networking/nc_bloaty.c | 58 +++++++++++++++++++++++++++++------------- 1 file changed, 40 insertions(+), 18 deletions(-) diff --git a/networking/nc_bloaty.c b/networking/nc_bloaty.c index 62a025116..00ba6f114 100644 --- a/networking/nc_bloaty.c +++ b/networking/nc_bloaty.c @@ -63,6 +63,12 @@ //usage: " -e PROG Run PROG after connect (must be last)" //usage: IF_NC_SERVER( //usage: "\n -l Listen mode, for inbound connects" +//usage: "\n -lk With -e, provides persistent server" +/* -ll does the same as -lk, but its our extension, while -k is BSD'd, + * presumably more widely known. Therefore we advertise it, not -ll. + * I would like to drop -ll support, but our "small" nc supports it, + * and Rob uses it. + */ //usage: ) //usage: "\n -p PORT Local port" //usage: "\n -s ADDR Local address" @@ -166,18 +172,14 @@ enum { OPT_v = (1 << 4), OPT_w = (1 << 5), OPT_l = (1 << 6) * ENABLE_NC_SERVER, - OPT_i = (1 << (6+ENABLE_NC_SERVER)) * ENABLE_NC_EXTRA, - OPT_o = (1 << (7+ENABLE_NC_SERVER)) * ENABLE_NC_EXTRA, - OPT_z = (1 << (8+ENABLE_NC_SERVER)) * ENABLE_NC_EXTRA, + OPT_k = (1 << 7) * ENABLE_NC_SERVER, + OPT_i = (1 << (7+2*ENABLE_NC_SERVER)) * ENABLE_NC_EXTRA, + OPT_o = (1 << (8+2*ENABLE_NC_SERVER)) * ENABLE_NC_EXTRA, + OPT_z = (1 << (9+2*ENABLE_NC_SERVER)) * ENABLE_NC_EXTRA, }; #define o_nflag (option_mask32 & OPT_n) #define o_udpmode (option_mask32 & OPT_u) -#if ENABLE_NC_SERVER -#define o_listen (option_mask32 & OPT_l) -#else -#define o_listen 0 -#endif #if ENABLE_NC_EXTRA #define o_ofile (option_mask32 & OPT_o) #define o_zero (option_mask32 & OPT_z) @@ -298,7 +300,7 @@ static int connect_w_timeout(int fd) incoming and returns an open connection *from* someplace. If we were given host/port args, any connections from elsewhere are rejected. This in conjunction with local-address binding should limit things nicely... */ -static void dolisten(void) +static void dolisten(int is_persistent, char **proggie) { int rr; @@ -371,6 +373,7 @@ create new one, and bind() it. TODO */ xconnect(netfd, &remend.u.sa, ouraddr->len); } else { /* TCP */ + another: arm(o_wait); /* wrap this in a timer, too; 0 = forever */ if (setjmp(jbuf) == 0) { again: @@ -405,6 +408,19 @@ create new one, and bind() it. TODO */ unarm(); } else bb_error_msg_and_die("timeout"); + + if (is_persistent && proggie) { + /* -l -k -e PROG */ + signal(SIGCHLD, SIG_IGN); /* no zombies please */ + if (xvfork() != 0) { + /* parent: go back and accept more connections */ + close(rr); + goto another; + } + /* child */ + signal(SIGCHLD, SIG_DFL); + } + xmove_fd(rr, netfd); /* dump the old socket, here's our new one */ /* find out what address the connection was *to* on our end, in case we're doing a listen-on-any on a multihomed machine. This allows one to @@ -454,6 +470,9 @@ create new one, and bind() it. TODO */ if (!o_nflag) free(remhostname); } + + if (proggie) + doexec(proggie); } /* udptest: @@ -730,6 +749,7 @@ int nc_main(int argc UNUSED_PARAM, char **argv) char *themdotted = themdotted; /* for compiler */ char **proggie; int x; + unsigned cnt_l = 0; unsigned o_lport = 0; INIT_G(); @@ -760,7 +780,7 @@ int nc_main(int argc UNUSED_PARAM, char **argv) if (proggie[0][0] == '-') { char *optpos = *proggie + 1; /* Skip all valid opts w/o params */ - optpos = optpos + strspn(optpos, "nuv"IF_NC_SERVER("l")IF_NC_EXTRA("z")); + optpos = optpos + strspn(optpos, "nuv"IF_NC_SERVER("lk")IF_NC_EXTRA("z")); if (*optpos == 'e' && !optpos[1]) { *optpos = '\0'; proggie++; @@ -774,17 +794,21 @@ int nc_main(int argc UNUSED_PARAM, char **argv) e_found: // -g -G -t -r deleted, unimplemented -a deleted too - opt_complementary = "?2:vv:w+"; /* max 2 params; -v is a counter; -w N */ - getopt32(argv, "np:s:uvw:" IF_NC_SERVER("l") + opt_complementary = "?2:vv:ll:w+"; /* max 2 params; -v and -l are counters; -w N */ + getopt32(argv, "np:s:uvw:" IF_NC_SERVER("lk") IF_NC_EXTRA("i:o:z"), &str_p, &str_s, &o_wait - IF_NC_EXTRA(, &str_i, &str_o), &o_verbose); + IF_NC_EXTRA(, &str_i, &str_o), &o_verbose IF_NC_SERVER(, &cnt_l)); argv += optind; #if ENABLE_NC_EXTRA if (option_mask32 & OPT_i) /* line-interval time */ o_interval = xatou_range(str_i, 1, 0xffff); #endif +#if ENABLE_NC_SERVER //if (option_mask32 & OPT_l) /* listen mode */ + if (option_mask32 & OPT_k) /* persistent server mode */ + cnt_l = 2; +#endif //if (option_mask32 & OPT_n) /* numeric-only, no DNS lookups */ //if (option_mask32 & OPT_o) /* hexdump log */ if (option_mask32 & OPT_p) { /* local source port */ @@ -833,7 +857,7 @@ int nc_main(int argc UNUSED_PARAM, char **argv) if (o_udpmode) socket_want_pktinfo(netfd); if (!ENABLE_FEATURE_UNIX_LOCAL - || o_listen + || cnt_l != 0 /* listen */ || ouraddr->u.sa.sa_family != AF_UNIX ) { xbind(netfd, &ouraddr->u.sa, ouraddr->len); @@ -862,11 +886,9 @@ int nc_main(int argc UNUSED_PARAM, char **argv) xmove_fd(xopen(str_o, O_WRONLY|O_CREAT|O_TRUNC), ofd); #endif - if (o_listen) { - dolisten(); + if (cnt_l != 0) { + dolisten((cnt_l - 1), proggie); /* dolisten does its own connect reporting */ - if (proggie) /* -e given? */ - doexec(proggie); x = readwrite(); /* it even works with UDP! */ } else { /* Outbound connects. Now we're more picky about args... */ -- 2.25.1