ref: 66892eb133865ec02faa8e64cdfa2f867f9e1e87
dir: /sys/src/ape/lib/bsd/getprotobyname.c/
/* posix */ #include <sys/types.h> #include <unistd.h> #include <stdlib.h> #include <stdio.h> #include <fcntl.h> #include <string.h> #include <errno.h> /* bsd extensions */ #include <sys/uio.h> #include <sys/socket.h> #include <netinet/in.h> #include <netdb.h> #include "priv.h" extern int h_errno; enum { Nname= 6, }; static struct protoent r; struct protoent *getprotobyname(const char *name) { int fd, i, m; char *p, *bp; int nn, na; unsigned long x; static char buf[1024], proto[1024]; static char *nptr[Nname+1]; /* connect to server */ fd = open("/net/cs", O_RDWR); if(fd < 0){ h_errno = NO_RECOVERY; return 0; } /* construct the query, always expect a protocol# back */ snprintf(buf, sizeof buf, "!protocol=%s ipv4proto=*", name); /* query the server */ if(write(fd, buf, strlen(buf)) < 0){ h_errno = TRY_AGAIN; 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, "protocol") == 0){ if(!nn) r.p_name = p; if(nn < Nname) nptr[nn++] = p; } else if(strcmp(bp, "ipv4proto") == 0){ r.p_proto = atoi(p); na++; } while(*p && *p != ' ') p++; if(*p) *p++ = 0; bp = p; } nptr[nn] = 0; r.p_aliases = nptr; if (nn+na == 0) return 0; return &r; }