ref: 42924ab37b6c00e9e6d437bddfe12633e43de634
dir: /libc/dial.c/
#include <u.h> #include <libc.h> typedef struct DS DS; static int call(char*, char*, DS*); static int csdial(DS*); static void _dial_string_parse(char*, DS*); enum { Maxstring = 128, Maxpath = 256, }; struct DS { /* dist string */ char buf[Maxstring]; char *netdir; char *proto; char *rem; /* other args */ char *local; char *dir; int *cfdp; }; /* * the dialstring is of the form '[/net/]proto!dest' */ int dial(char *dest, char *local, char *dir, int *cfdp) { DS ds; int rv; char err[ERRMAX], alterr[ERRMAX]; ds.local = local; ds.dir = dir; ds.cfdp = cfdp; _dial_string_parse(dest, &ds); if(ds.netdir) return csdial(&ds); ds.netdir = "/net"; rv = csdial(&ds); if(rv >= 0) return rv; err[0] = '\0'; errstr(err, sizeof err); if(strstr(err, "refused") != 0){ werrstr("%s", err); return rv; } ds.netdir = "/net.alt"; rv = csdial(&ds); if(rv >= 0) return rv; alterr[0] = 0; errstr(alterr, sizeof alterr); if(strstr(alterr, "translate") || strstr(alterr, "does not exist")) werrstr("%s", err); else werrstr("%s", alterr); return rv; } static int csdial(DS *ds) { int n, fd, rv; char *p, buf[Maxstring], clone[Maxpath], err[ERRMAX], besterr[ERRMAX]; /* * open connection server */ snprint(buf, sizeof(buf), "%s/cs", ds->netdir); fd = open(buf, ORDWR); if(fd < 0){ /* no connection server, don't translate */ snprint(clone, sizeof(clone), "%s/%s/clone", ds->netdir, ds->proto); return call(clone, ds->rem, ds); } /* * ask connection server to translate */ snprint(buf, sizeof(buf), "%s!%s", ds->proto, ds->rem); if(write(fd, buf, strlen(buf)) < 0){ close(fd); return -1; } /* * loop through each address from the connection server till * we get one that works. */ *besterr = 0; rv = -1; seek(fd, 0, 0); strcpy(err, "cs gave empty translation list"); while((n = read(fd, buf, sizeof(buf) - 1)) > 0){ buf[n] = 0; p = strchr(buf, ' '); if(p == 0) continue; *p++ = 0; rv = call(buf, p, ds); if(rv >= 0) break; err[0] = '\0'; errstr(err, sizeof err); if(strstr(err, "does not exist") == 0) strcpy(besterr, err); } close(fd); if(rv < 0 && *besterr) werrstr("%s", besterr); else werrstr("%s", err); return rv; } static int call(char *clone, char *dest, DS *ds) { int fd, cfd, n; char name[Maxpath], data[Maxpath], *p; cfd = open(clone, ORDWR); if(cfd < 0) return -1; /* get directory name */ n = read(cfd, name, sizeof(name)-1); if(n < 0){ close(cfd); return -1; } name[n] = 0; for(p = name; *p == ' '; p++) ; snprint(name, sizeof(name), "%ld", strtoul(p, 0, 0)); p = strrchr(clone, '/'); *p = 0; if(ds->dir) snprint(ds->dir, NETPATHLEN, "%s/%s", clone, name); snprint(data, sizeof(data), "%s/%s/data", clone, name); /* connect */ if(ds->local) snprint(name, sizeof(name), "connect %s %s", dest, ds->local); else snprint(name, sizeof(name), "connect %s", dest); if(write(cfd, name, strlen(name)) < 0){ close(cfd); return -1; } /* open data connection */ fd = open(data, ORDWR); if(fd < 0){ print("open %s: %r\n", data); close(cfd); return -1; } if(ds->cfdp) *ds->cfdp = cfd; else close(cfd); return fd; } /* * parse a dial string */ static void _dial_string_parse(char *str, DS *ds) { char *p, *p2; strncpy(ds->buf, str, Maxstring); ds->buf[Maxstring-1] = 0; p = strchr(ds->buf, '!'); if(p == 0) { ds->netdir = 0; ds->proto = "net"; ds->rem = ds->buf; } else { if(*ds->buf != '/' && *ds->buf != '#'){ ds->netdir = 0; ds->proto = ds->buf; } else { for(p2 = p; *p2 != '/'; p2--) ; *p2++ = 0; ds->netdir = ds->buf; ds->proto = p2; } *p = 0; ds->rem = p + 1; } }