ref: af23bb343a067d5346696b788f4cce5b744cd51d
dir: /sys/src/ape/lib/bsd/getservbyname.c/
/* posix */ #include <sys/types.h> #include <unistd.h> #include <stdlib.h> #include <stdio.h> #include <fcntl.h> #include <string.h> #include <errno.h> #include <ctype.h> /* bsd extensions */ #include <sys/uio.h> #include <sys/socket.h> #include <netinet/in.h> #include <netdb.h> #include "priv.h" enum { Nname= 6, }; /* * for inet addresses only */ struct servent* getservbyname(char *name, char *proto) { int i, fd, m, num; char *p, *bp; int nn, na; static struct servent s; static char buf[1024]; static char *nptr[Nname+1]; num = 1; for(p = name; *p; p++) if(!isdigit(*p)) num = 0; s.s_name = 0; /* connect to server */ fd = open("/net/cs", O_RDWR); if(fd < 0) return 0; /* construct the query, always expect an ip# back */ if(num) snprintf(buf, sizeof buf, "!port=%s %s=*", name, proto); else snprintf(buf, sizeof buf, "!%s=%s port=*", proto, name); /* query the server */ if(write(fd, buf, strlen(buf)) < 0){ close(fd); return 0; } lseek(fd, 0, 0); for(i = 0; i < sizeof(buf)-1; i += m){ m = read(fd, buf+i, sizeof(buf) - 1 - i); if(m <= 0) break; buf[i+m++] = ' '; } close(fd); buf[i] = 0; /* parse the reply */ nn = na = 0; for(bp = buf;;){ p = strchr(bp, '='); if(p == 0) break; *p++ = 0; if(strcmp(bp, proto) == 0){ if(nn < Nname) nptr[nn++] = p; } else if(strcmp(bp, "port") == 0){ s.s_port = htons(atoi(p)); } while(*p && *p != ' ') p++; if(*p) *p++ = 0; bp = p; } if(nn+na == 0) return 0; nptr[nn] = 0; s.s_aliases = nptr; if(s.s_name == 0) s.s_name = nptr[0]; return &s; }