--- /dev/null +++ b/include/netinet/ether.h @@ -0,0 +1,10 @@ +#ifndef _NETINET_ETHER_H +#define _NETINET_ETHER_H + +char *ether_ntoa(const struct ether_addr *); +struct ether_addr *ether_aton(const char *); +int ether_ntohost(char *, const struct ether_addr *); +int ether_hostton(const char *, struct ether_addr *); +int ether_line(const char *, struct ether_addr *, char *); + +#endif /* !_NETINET_ETHER_H */ --- /dev/null +++ b/src/network/ethers.c @@ -0,0 +1,180 @@ +/* Origin NetBSD: src/lib/libc/net/ethers.c */ + +/* + * ethers(3N) a la Sun. + * + * Written by Roland McGrath <roland@...b.com> 10/14/93. + * Public domain. + * + * port for musl by Abdoulaye Walsimou GAYE <awg@...toolkit.org> 2012/10/15 + */ + +#define _BSD_SOURCE +#include <net/ethernet.h> +#include <netinet/ether.h> + +#include <sys/param.h> +#include <assert.h> +#include <errno.h> +#include <paths.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#ifndef _PATH_ETHERS +#define _PATH_ETHERS "/etc/ethers" +#endif + +/* + * ether_ntoa(): + * This function converts this structure into an ASCII string of the form + * ``xx:xx:xx:xx:xx:xx'', consisting of 6 hexadecimal numbers separated + * by colons. It returns a pointer to a static buffer that is reused for + * each call. + */ +char *ether_ntoa(const struct ether_addr *e) +{ + static char a[18]; + + assert(e != NULL); + + (void) snprintf(a, sizeof a, "%02x:%02x:%02x:%02x:%02x:%02x", + e->ether_addr_octet[0], e->ether_addr_octet[1], + e->ether_addr_octet[2], e->ether_addr_octet[3], + e->ether_addr_octet[4], e->ether_addr_octet[5]); + return a; +} + +/* + * ether_aton(): + * This function converts an ASCII string of the same form and to a structure + * containing the 6 octets of the address. It returns a pointer to a + * static structure that is reused for each call. + */ +struct ether_addr *ether_aton(const char *s) +{ + static struct ether_addr n; + unsigned int i[6]; + + assert(s != NULL); + + if (sscanf(s, " %x:%x:%x:%x:%x:%x ", &i[0], &i[1], + &i[2], &i[3], &i[4], &i[5]) == 6) { + n.ether_addr_octet[0] = (unsigned char)i[0]; + n.ether_addr_octet[1] = (unsigned char)i[1]; + n.ether_addr_octet[2] = (unsigned char)i[2]; + n.ether_addr_octet[3] = (unsigned char)i[3]; + n.ether_addr_octet[4] = (unsigned char)i[4]; + n.ether_addr_octet[5] = (unsigned char)i[5]; + return &n; + } + return NULL; +} + +/* + * ether_ntohost(): + * This function interrogates the data base mapping host names to Ethernet + * addresses, /etc/ethers. + * It looks up the given Ethernet address and writes the associated host name + * into the character buffer passed. + * It returns zero if it finds the requested host name and -1 if not. + */ +int ether_ntohost(char *hostname, const struct ether_addr *e) +{ + FILE *f; + char *p; + size_t len; + struct ether_addr try; + + assert(hostname != NULL); + assert(e != NULL); + + f = fopen(_PATH_ETHERS, "r"); + if (f == NULL) + return -1; + while ((p = fgetln(f, &len)) != NULL) { + if (p[len - 1] != '\n') + continue; /* skip lines w/o \n */ + p[--len] = '\0'; + if (ether_line(p, &try, hostname) == 0 && + memcmp(&try, e, sizeof try) == 0) { + (void)fclose(f); + return 0; + } + } + (void)fclose(f); + errno = ENOENT; + return -1; +} + +/* + * ether_hostton(): + * This function interrogates the data base mapping host names to Ethernet + * addresses, /etc/ethers. + * It looks up the given host name and writes the associated Ethernet address + * into the structure passed. + * It returns zero if it finds the requested address and -1 if not. + */ +int ether_hostton(const char *hostname, struct ether_addr *e) +{ + FILE *f; + char *p; + size_t len; + char try[MAXHOSTNAMELEN + 1]; + + assert(hostname != NULL); + assert(e != NULL); + + f = fopen(_PATH_ETHERS, "r"); + if (f==NULL) + return -1; + + while ((p = fgetln(f, &len)) != NULL) { + if (p[len - 1] != '\n') + continue; /* skip lines w/o \n */ + p[--len] = '\0'; + if (ether_line(p, e, try) == 0 && strcmp(hostname, try) == 0) { + (void)fclose(f); + return 0; + } + } + (void)fclose(f); + errno = ENOENT; + return -1; +} + +/* + * ether_line(): + * This function parses a line from the /etc/ethers file and fills in the passed + * ``struct ether_addr'' and character buffer with the Ethernet address and host + * name on the line. + * It returns zero if the line was successfully parsed and -1 if not. + */ +int ether_line(const char *l, struct ether_addr *e, char *hostname) +{ + unsigned int i[6]; + +#define S2(arg) #arg +#define S1(arg) S2(arg) + static const char fmt[] = " %x:%x:%x:%x:%x:%x" + " %" S1(MAXHOSTNAMELEN) "s\n"; +#undef S2 +#undef S1 + + assert(l != NULL); + assert(e != NULL); + assert(hostname != NULL); + + if (sscanf(l, fmt, + &i[0], &i[1], &i[2], &i[3], &i[4], &i[5], hostname) == 7) { + e->ether_addr_octet[0] = (unsigned char)i[0]; + e->ether_addr_octet[1] = (unsigned char)i[1]; + e->ether_addr_octet[2] = (unsigned char)i[2]; + e->ether_addr_octet[3] = (unsigned char)i[3]; + e->ether_addr_octet[4] = (unsigned char)i[4]; + e->ether_addr_octet[5] = (unsigned char)i[5]; + return 0; + } + errno = EINVAL; + return -1; +}