ref: e0c19ae048ae671883fd4d27d5f617c02020bdf5
dir: /sys/src/libc/9sys/dial.c/
#include <u.h> #include <libc.h> typedef struct DS DS; static int call(char*, 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]; 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; errstr(err, sizeof err); if(strcmp(err, "interrupted") == 0 || strstr(err, "refused") != nil){ errstr(err, sizeof err); return rv; } ds.netdir = "/net.alt"; rv = csdial(&ds); if(rv >= 0) return rv; errstr(err, sizeof err); if(strstr(err, "translate") == nil && strstr(err, "does not exist") == nil) errstr(err, sizeof err); return rv; } static int csdial(DS *ds) { int n, fd, rv; char *rem, *loc, buf[Maxstring], clone[Maxpath], err[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->local, 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. */ rv = -1; *err = 0; seek(fd, 0, 0); while((n = read(fd, buf, sizeof(buf) - 1)) > 0){ buf[n] = 0; rem = strchr(buf, ' '); if(rem == nil) continue; *rem++ = 0; loc = strchr(rem, ' '); if(loc != nil) *loc++ = 0; rv = call(buf, rem, ds->local!=nil? ds->local: loc, ds); if(rv >= 0) break; errstr(err, sizeof err); if(strcmp(err, "interrupted") == 0) break; if(strstr(err, "does not exist") != nil) errstr(err, sizeof err); /* get previous error back */ } close(fd); /* restore errstr if any */ if(rv < 0 && *err) errstr(err, sizeof err); return rv; } static int call(char *clone, char *remote, char *local, DS *ds) { int fd, cfd, n; char cname[Maxpath], name[Maxpath], data[Maxpath], *p; /* because cs is in a different name space, replace the mount point */ if(*clone == '/' || *clone == '#'){ p = strchr(clone+1, '/'); if(p == nil) p = clone; else p++; } else p = clone; snprint(cname, sizeof cname, "%s/%s", ds->netdir, p); cfd = open(cname, 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(cname, '/'); *p = 0; if(ds->dir) snprint(ds->dir, NETPATHLEN, "%s/%s", cname, name); snprint(data, sizeof(data), "%s/%s/data", cname, name); /* connect */ if(local != nil) snprint(name, sizeof(name), "connect %s %s", remote, local); else snprint(name, sizeof(name), "connect %s", remote); if(write(cfd, name, strlen(name)) < 0){ close(cfd); return -1; } /* open data connection */ fd = open(data, ORDWR); if(fd < 0){ 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 { p2 = ds->buf; if(*p2 == '#'){ p2 = strchr(p2, '/'); if(p2 == nil || p2 > p) p2 = ds->buf; } if(*p2 != '/'){ 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; } }