diff options
Diffstat (limited to 'src/network/getservbyport_r.c')
-rw-r--r-- | src/network/getservbyport_r.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/src/network/getservbyport_r.c b/src/network/getservbyport_r.c new file mode 100644 index 00000000..004a6168 --- /dev/null +++ b/src/network/getservbyport_r.c @@ -0,0 +1,43 @@ +#define _GNU_SOURCE +#include <sys/socket.h> +#include <netinet/in.h> +#include <netdb.h> +#include <inttypes.h> +#include <errno.h> +#include <string.h> + +int getservbyport_r(int port, const char *prots, + struct servent *se, char *buf, size_t buflen, struct servent **res) +{ + int i; + struct sockaddr_in sin = { + .sin_family = AF_INET, + .sin_port = port, + }; + + /* Align buffer */ + i = (uintptr_t)buf & sizeof(char *)-1; + if (!i) i = sizeof(char *); + if (buflen < 3*sizeof(char *)-i) { + errno = ERANGE; + return -1; + } + buf += sizeof(char *)-i; + buflen -= sizeof(char *)-i; + + if (strcmp(prots, "tcp") && strcmp(prots, "udp")) return -1; + + se->s_port = port; + se->s_proto = (char *)prots; + se->s_aliases = (void *)buf; + buf += 2*sizeof(char *); + buflen -= 2*sizeof(char *); + se->s_aliases[1] = 0; + se->s_aliases[0] = se->s_name = buf; + + if (getnameinfo((void *)&sin, sizeof sin, 0, 0, buf, buflen, + strcmp(prots, "udp") ? 0 : NI_DGRAM) < 0) return -1; + + *res = se; + return 0; +} |