ref: 26e00d014cebde8bc07725700b5ac9c0cade8171
dir: /sys/src/ape/lib/net/dial.c/
#include <stdlib.h> #include <sys/types.h> #include <string.h> #include <fcntl.h> #include <stdio.h> #include <unistd.h> #include <libnet.h> #define NAMELEN 28 static int call(char *clone, char *dest, int *cfdp, char *dir, char *local) { int fd, cfd; int n; char name[3*NAMELEN+5]; char data[3*NAMELEN+10]; char *p; cfd = open(clone, O_RDWR); 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; p = strrchr(clone, '/'); *p = 0; if(dir) sprintf(dir, "%.*s/%.*s", 2*NAMELEN+1, clone, NAMELEN, name); sprintf(data, "%.*s/%.*s/data", 2*NAMELEN+1, clone, NAMELEN, name); /* set local side (port number, for example) if we need to */ if(local) sprintf(name, "connect %.*s %.*s", 2*NAMELEN, dest, NAMELEN, local); else sprintf(name, "connect %.*s", 2*NAMELEN, dest); /* connect */ if(write(cfd, name, strlen(name)) < 0){ close(cfd); return -1; } /* open data connection */ fd = open(data, O_RDWR); if(fd < 0){ close(cfd); return -1; } if(cfdp) *cfdp = cfd; else close(cfd); return fd; } int dial(char *dest, char *local, char *dir, int *cfdp) { char net[128]; char netdir[128], csname[NETPATHLEN], *slp; char clone[NAMELEN+12]; char *p; int n; int fd; int rv; /* go for a standard form net!... */ p = strchr(dest, '!'); if(p == 0){ sprintf(net, "net!%.*s", sizeof(net)-5, dest); } else { strncpy(net, dest, sizeof(net)-1); net[sizeof(net)-1] = 0; } slp = strrchr(net, '/'); if (slp != 0) { *slp++ = '\0'; strcpy(netdir, net); memmove(net, slp, strlen(slp)+1); } else strcpy(netdir, "/net"); /* call the connection server */ sprintf(csname, "%s/cs", netdir); fd = open(csname, O_RDWR); if(fd < 0){ /* no connection server, don't translate */ p = strchr(net, '!'); *p++ = 0; sprintf(clone, "%s/%s/clone", netdir, net); return call(clone, p, cfdp, dir, local); } /* * send dest to connection to translate */ if(write(fd, net, strlen(net)) < 0){ close(fd); return -1; } /* * loop through each address from the connection server till * we get one that works. */ rv = -1; lseek(fd, 0, 0); while((n = read(fd, net, sizeof(net) - 1)) > 0){ net[n] = 0; p = strchr(net, ' '); if(p == 0) continue; *p++ = 0; rv = call(net, p, cfdp, dir, local); if(rv >= 0) break; } close(fd); return rv; }