ref: 2985d53b7a06d8a1712493aa899d6ffcfacd9e3b
dir: /sys/src/libc/9sys/announce.c/
#include <u.h> #include <libc.h> #include <ctype.h> static int nettrans(char*, char*, int na, char*, int); enum { Maxpath= 256, }; /* * announce a network service. */ int announce(char *addr, char *dir) { int ctl, n, m; char buf[Maxpath]; char buf2[Maxpath]; char netdir[Maxpath]; char naddr[Maxpath]; char *cp; /* * translate the address */ if(nettrans(addr, naddr, sizeof(naddr), netdir, sizeof(netdir)) < 0) return -1; /* * get a control channel */ ctl = open(netdir, ORDWR); if(ctl<0){ werrstr("announce opening %s: %r", netdir); return -1; } cp = strrchr(netdir, '/'); if(cp == nil){ werrstr("announce arg format %s", netdir); close(ctl); return -1; } *cp = 0; /* * find out which line we have */ n = snprint(buf, sizeof(buf), "%s/", netdir); m = read(ctl, &buf[n], sizeof(buf)-n-1); if(m <= 0){ werrstr("announce reading %s: %r", netdir); close(ctl); return -1; } buf[n+m] = 0; /* * make the call */ n = snprint(buf2, sizeof(buf2), "announce %s", naddr); if(write(ctl, buf2, n)!=n){ werrstr("announce writing %s: %r", netdir); close(ctl); return -1; } /* * return directory etc. */ if(dir){ strncpy(dir, buf, NETPATHLEN); dir[NETPATHLEN-1] = 0; } return ctl; } /* * listen for an incoming call */ int listen(char *dir, char *newdir) { int ctl, n, m; char buf[Maxpath]; char *cp; /* * open listen, wait for a call */ snprint(buf, sizeof(buf), "%s/listen", dir); ctl = open(buf, ORDWR); if(ctl < 0){ werrstr("listen opening %s: %r", buf); return -1; } /* * find out which line we have */ strncpy(buf, dir, sizeof(buf) - 1); buf[sizeof(buf) - 1] = 0; cp = strrchr(buf, '/'); if(cp == nil){ close(ctl); werrstr("listen arg format %s", dir); return -1; } *++cp = 0; n = cp-buf; m = read(ctl, cp, sizeof(buf) - n - 1); if(m <= 0){ close(ctl); werrstr("listen reading %s/listen: %r", dir); return -1; } buf[n+m] = 0; /* * return directory etc. */ if(newdir){ strncpy(newdir, buf, NETPATHLEN); newdir[NETPATHLEN-1] = 0; } return ctl; } /* * accept a call, return an fd to the open data file */ int accept(int ctl, char *dir) { char buf[Maxpath]; char *num; long n; num = strrchr(dir, '/'); if(num == nil) num = dir; else num++; n = snprint(buf, sizeof(buf), "accept %s", num); write(ctl, buf, n); /* ignore return value, network might not need accepts */ snprint(buf, sizeof(buf), "%s/data", dir); return open(buf, ORDWR); } /* * reject a call, tell device the reason for the rejection */ int reject(int ctl, char *dir, char *cause) { char buf[Maxpath]; char *num; long n; num = strrchr(dir, '/'); if(num == 0) num = dir; else num++; snprint(buf, sizeof(buf), "reject %s %s", num, cause); n = strlen(buf); if(write(ctl, buf, n) != n) return -1; return 0; } /* * perform the identity translation (in case we can't reach cs) */ static int identtrans(char *netdir, char *addr, char *naddr, int na, char *file, int nf) { char proto[Maxpath]; char *p; USED(nf); /* parse the protocol */ strncpy(proto, addr, sizeof(proto)); proto[sizeof(proto)-1] = 0; p = strchr(proto, '!'); if(p) *p++ = 0; snprint(file, nf, "%s/%s/clone", netdir, proto); strncpy(naddr, p, na); naddr[na-1] = 0; return 1; } /* * call up the connection server and get a translation */ static int nettrans(char *addr, char *naddr, int na, char *file, int nf) { int i, fd; char buf[Maxpath]; char netdir[Maxpath]; char *p, *p2; long n; /* * parse, get network directory */ p = strchr(addr, '!'); if(p == 0){ werrstr("bad dial string: %s", addr); return -1; } if(*addr != '/' && *addr != '#'){ strncpy(netdir, "/net", sizeof(netdir)); netdir[sizeof(netdir) - 1] = 0; } else { for(p2 = p; p2 > addr && *p2 != '/'; p2--) ; i = p2 - addr; if(i == 0 || i >= sizeof(netdir)){ werrstr("bad dial string: %s", addr); return -1; } strncpy(netdir, addr, i); netdir[i] = 0; addr = p2 + 1; } /* * ask the connection server */ snprint(buf, sizeof(buf), "%s/cs", netdir); fd = open(buf, ORDWR); if(fd < 0) return identtrans(netdir, addr, naddr, na, file, nf); if(write(fd, addr, strlen(addr)) < 0){ close(fd); return -1; } seek(fd, 0, 0); n = read(fd, buf, sizeof(buf)-1); close(fd); if(n <= 0) return -1; buf[n] = 0; /* * parse the reply */ p = strchr(buf, ' '); if(p == 0) return -1; *p++ = 0; strncpy(naddr, p, na); naddr[na-1] = 0; if(buf[0] == '/'){ p = strchr(buf+1, '/'); if(p == nil) p = buf; else p++; } snprint(file, nf, "%s/%s", netdir, p); return 0; }