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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 14:37:38 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 14:37:38 +0000 |
commit | ae581a19fbe896a797450b9d9573fb66f2735227 (patch) | |
tree | 56c40be8518a29c9351364d13a9676aa83932dc0 /lib/util/getaddrinfo.c | |
parent | Initial commit. (diff) | |
download | sudo-ae581a19fbe896a797450b9d9573fb66f2735227.tar.xz sudo-ae581a19fbe896a797450b9d9573fb66f2735227.zip |
Adding upstream version 1.9.13p3.upstream/1.9.13p3upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | lib/util/getaddrinfo.c | 406 |
1 files changed, 406 insertions, 0 deletions
diff --git a/lib/util/getaddrinfo.c b/lib/util/getaddrinfo.c new file mode 100644 index 0000000..ad0ea5f --- /dev/null +++ b/lib/util/getaddrinfo.c @@ -0,0 +1,406 @@ +/* + * Replacement for a missing getaddrinfo. + * + * This is an implementation of getaddrinfo for systems that don't have one so + * that networking code can use a consistent interface without #ifdef. It is + * a fairly minimal implementation, with the following limitations: + * + * - IPv4 support only. IPv6 is not supported. + * - AI_ADDRCONFIG is ignored. + * - Not thread-safe due to gethostbyname and getservbyname. + * - SOCK_DGRAM and SOCK_STREAM only. + * - Multiple possible socket types only generate one addrinfo struct. + * - Protocol hints aren't used correctly. + * + * The last four issues could probably be easily remedied, but haven't been + * needed to date. Adding IPv6 support isn't worth it; systems with IPv6 + * support should already have getaddrinfo. + * + * The canonical version of this file is maintained in the rra-c-util package, + * which can be found at <http://www.eyrie.org/~eagle/software/rra-c-util/>. + * + * Written by Russ Allbery <rra@stanford.edu> + * + * The authors hereby relinquish any claim to any copyright that they may have + * in this work, whether granted under contract or by operation of law or + * international treaty, and hereby commit to the public, at large, that they + * shall not, at any time in the future, seek to enforce any copyright in this + * work against any person or entity, or prevent any person or entity from + * copying, publishing, distributing or creating derivative works of this + * work. + */ + +#include <config.h> + +#ifndef HAVE_GETADDRINFO + +#include <sys/types.h> +#include <sys/socket.h> + +#include <stdlib.h> +#include <string.h> +#include <limits.h> +#include <netdb.h> +#include <errno.h> + +#include <arpa/inet.h> +#include <netinet/in.h> +#ifdef NEED_RESOLV_H +# include <arpa/nameser.h> +# include <resolv.h> +#endif /* NEED_RESOLV_H */ + +#include "sudo_compat.h" +#include "compat/getaddrinfo.h" + +/* We need access to h_errno to map errors from gethostbyname. */ +#ifndef HAVE_DECL_H_ERRNO +extern int h_errno; +#endif + +/* + * The netdb constants, which aren't always defined (particularly if h_errno + * isn't declared). We also make sure that a few of the less-used ones are + * defined so that we can deal with them in case statements. + */ +#ifndef HOST_NOT_FOUND +# define HOST_NOT_FOUND 1 +# define TRY_AGAIN 2 +# define NO_RECOVERY 3 +# define NO_DATA 4 +#endif +#ifndef NETDB_INTERNAL +# define NETDB_INTERNAL -1 +#endif + +/* + * If we're running the test suite, rename the functions to avoid conflicts + * with the system version. Note that we don't rename the structures and + * constants, but that should be okay (except possibly for gai_strerror). + */ +#ifdef TESTING +# define gai_strerror test_gai_strerror +# define freeaddrinfo test_freeaddrinfo +# define getaddrinfo test_getaddrinfo +const char *test_gai_strerror(int); +void test_freeaddrinfo(struct addrinfo *); +int test_getaddrinfo(const char *, const char *, const struct addrinfo *, + struct addrinfo **); +#endif + +/* + * If the platform doesn't support AI_NUMERICSERV or AI_NUMERICHOST, + * pick some other values for them. + */ +#ifdef TESTING +# if AI_NUMERICSERV == 0 +# undef AI_NUMERICSERV +# define AI_NUMERICSERV 0x0080 +# endif +# if AI_NUMERICHOST == 0 +# undef AI_NUMERICHOST +# define AI_NUMERICHOST 0x0100 +# endif +#endif + +/* + * Value representing all of the hint flags set. Linux uses flags up to + * 0x0400, so be sure not to break when testing on that platform. + */ +#ifdef TESTING +# ifdef HAVE_GETADDRINFO +# define AI_INTERNAL_ALL 0x04ff +# else +# define AI_INTERNAL_ALL 0x01ff +# endif +#else +# define AI_INTERNAL_ALL 0x007f +#endif + +/* Table of strings corresponding to the EAI_* error codes. */ +static const char * const gai_errors[] = { + "Host name lookup failure", /* 1 EAI_AGAIN */ + "Invalid flag value", /* 2 EAI_BADFLAGS */ + "Unknown server error", /* 3 EAI_FAIL */ + "Unsupported address family", /* 4 EAI_FAMILY */ + "Memory allocation failure", /* 5 EAI_MEMORY */ + "Host unknown or not given", /* 6 EAI_NONAME */ + "Service not supported for socket", /* 7 EAI_SERVICE */ + "Unsupported socket type", /* 8 EAI_SOCKTYPE */ + "System error", /* 9 EAI_SYSTEM */ + "Supplied buffer too small", /* 10 EAI_OVERFLOW */ +}; + +/* Macro to set the len attribute of sockaddr_in. */ +#ifdef HAVE_STRUCT_SOCKADDR_IN_SIN_LEN +# define sin_set_length(s) ((s)->sin_len = sizeof(struct sockaddr_in)) +#else +# define sin_set_length(s) /* empty */ +#endif + +/* + * Return a constant string for a given EAI_* error code or a string + * indicating an unknown error. + */ +const char * +sudo_gai_strerror(int ecode) +{ + if (ecode < 1 || (size_t) ecode > nitems(gai_errors)) + return "Unknown error"; + else + return gai_errors[ecode - 1]; +} + + +/* + * Free a linked list of addrinfo structs. + */ +void +sudo_freeaddrinfo(struct addrinfo *ai) +{ + struct addrinfo *next; + + while (ai != NULL) { + next = ai->ai_next; + if (ai->ai_addr != NULL) + free(ai->ai_addr); + if (ai->ai_canonname != NULL) + free(ai->ai_canonname); + free(ai); + ai = next; + } +} + + +/* + * Allocate a new addrinfo struct, setting some defaults given that this + * implementation is IPv4 only. Also allocates an attached sockaddr_in and + * zeroes it, per the requirement for getaddrinfo. Takes the socktype, + * canonical name (which is copied if not NULL), address, and port. Returns + * NULL on a memory allocation failure. + */ +static struct addrinfo * +gai_addrinfo_new(int socktype, const char *canonical, struct in_addr addr, + unsigned short port) +{ + struct addrinfo *ai; + + ai = malloc(sizeof(*ai)); + if (ai == NULL) + return NULL; + ai->ai_addr = malloc(sizeof(struct sockaddr_in)); + if (ai->ai_addr == NULL) { + free(ai); + return NULL; + } + ai->ai_next = NULL; + if (canonical == NULL) + ai->ai_canonname = NULL; + else { + ai->ai_canonname = strdup(canonical); + if (ai->ai_canonname == NULL) { + freeaddrinfo(ai); + return NULL; + } + } + memset(ai->ai_addr, 0, sizeof(struct sockaddr_in)); + ai->ai_flags = 0; + ai->ai_family = AF_INET; + ai->ai_socktype = socktype; + ai->ai_protocol = (socktype == SOCK_DGRAM) ? IPPROTO_UDP : IPPROTO_TCP; + ai->ai_addrlen = sizeof(struct sockaddr_in); + ((struct sockaddr_in *) ai->ai_addr)->sin_family = AF_INET; + ((struct sockaddr_in *) ai->ai_addr)->sin_addr = addr; + ((struct sockaddr_in *) ai->ai_addr)->sin_port = htons(port); + sin_set_length((struct sockaddr_in *) ai->ai_addr); + return ai; +} + + +/* + * Look up a service. Takes the service name (which may be numeric), the hint + * flags, a pointer to the socket type (used to determine whether TCP or UDP + * services are of interest and, if 0, is filled in with the result of + * getservbyname if the service was not numeric), and a pointer to the + * addrinfo struct to fill in. Returns 0 on success or an EAI_* error on + * failure. + */ +static int +gai_service(const char *servname, int flags, int *type, unsigned short *port) +{ + struct servent *servent; + const char *protocol; + const char *errstr; + unsigned short value; + + value = sudo_strtonum(servname, 0, USHRT_MAX, &errstr); + if (errstr == NULL) { + *port = value; + } else if (errno == ERANGE) { + return EAI_SERVICE; + } else { + if (flags & AI_NUMERICSERV) + return EAI_NONAME; + if (*type != 0) + protocol = (*type == SOCK_DGRAM) ? "udp" : "tcp"; + else + protocol = NULL; + + /* + * We really technically should be generating an addrinfo struct for + * each possible protocol unless type is set, but this works well + * enough for what I need this for. + */ + servent = getservbyname(servname, protocol); + if (servent == NULL) + return EAI_NONAME; + if (strcmp(servent->s_proto, "udp") == 0) + *type = SOCK_DGRAM; + else if (strcmp(servent->s_proto, "tcp") == 0) + *type = SOCK_STREAM; + else + return EAI_SERVICE; + *port = htons(servent->s_port); + } + return 0; +} + + +/* + * Look up a host and fill in a linked list of addrinfo structs with the + * results, one per IP address of the returned host. Takes the name or IP + * address of the host as a string, the lookup flags, the type of socket (to + * fill into the addrinfo structs), the port (likewise), and a pointer to + * where the head of the linked list should be put. Returns 0 on success or + * the appropriate EAI_* error. + */ +static int +gai_lookup(const char *nodename, int flags, int socktype, unsigned short port, + struct addrinfo **res) +{ + struct addrinfo *ai, *first, *prev; + struct in_addr addr; + struct hostent *host; + const char *canonical; + int i; + + if (inet_pton(AF_INET, nodename, &addr)) { + canonical = (flags & AI_CANONNAME) ? nodename : NULL; + ai = gai_addrinfo_new(socktype, canonical, addr, port); + if (ai == NULL) + return EAI_MEMORY; + *res = ai; + return 0; + } else { + if (flags & AI_NUMERICHOST) + return EAI_NONAME; + host = gethostbyname(nodename); + if (host == NULL) + switch (h_errno) { + case HOST_NOT_FOUND: + return EAI_NONAME; + case TRY_AGAIN: + case NO_DATA: + return EAI_AGAIN; + case NO_RECOVERY: + return EAI_FAIL; + case NETDB_INTERNAL: + default: + return EAI_SYSTEM; + } + if (host->h_addr_list[0] == NULL) + return EAI_FAIL; + canonical = (flags & AI_CANONNAME) + ? ((host->h_name != NULL) ? host->h_name : nodename) + : NULL; + first = NULL; + prev = NULL; + for (i = 0; host->h_addr_list[i] != NULL; i++) { + if (host->h_length != sizeof(addr)) { + freeaddrinfo(first); + return EAI_FAIL; + } + memcpy(&addr, host->h_addr_list[i], sizeof(addr)); + ai = gai_addrinfo_new(socktype, canonical, addr, port); + if (ai == NULL) { + freeaddrinfo(first); + return EAI_MEMORY; + } + if (first == NULL) { + first = ai; + prev = ai; + } else { + prev->ai_next = ai; + prev = ai; + } + } + *res = first; + return 0; + } +} + + +/* + * The actual getaddrinfo implementation. + */ +int +sudo_getaddrinfo(const char *nodename, const char *servname, + const struct addrinfo *hints, struct addrinfo **res) +{ + struct addrinfo *ai; + struct in_addr addr; + int flags, socktype, status; + unsigned short port; + + /* Take the hints into account and check them for validity. */ + if (hints != NULL) { + flags = hints->ai_flags; + socktype = hints->ai_socktype; + if ((flags & AI_INTERNAL_ALL) != flags) + return EAI_BADFLAGS; + if (hints->ai_family != AF_UNSPEC && hints->ai_family != AF_INET) + return EAI_FAMILY; + if (socktype != 0 && socktype != SOCK_STREAM && socktype != SOCK_DGRAM) + return EAI_SOCKTYPE; + + /* EAI_SOCKTYPE isn't quite right, but there isn't anything better. */ + if (hints->ai_protocol != 0) { + int protocol = hints->ai_protocol; + if (protocol != IPPROTO_TCP && protocol != IPPROTO_UDP) + return EAI_SOCKTYPE; + } + } else { + flags = 0; + socktype = 0; + } + + /* + * See what we're doing. If nodename is null, either AI_PASSIVE is set or + * we're getting information for connecting to a service on the loopback + * address. Otherwise, we're getting information for connecting to a + * remote system. + */ + if (servname == NULL) + port = 0; + else { + status = gai_service(servname, flags, &socktype, &port); + if (status != 0) + return status; + } + if (nodename != NULL) + return gai_lookup(nodename, flags, socktype, port, res); + else { + if (servname == NULL) + return EAI_NONAME; + if ((flags & AI_PASSIVE) == AI_PASSIVE) + addr.s_addr = INADDR_ANY; + else + addr.s_addr = htonl(0x7f000001UL); + ai = gai_addrinfo_new(socktype, NULL, addr, port); + if (ai == NULL) + return EAI_MEMORY; + *res = ai; + return 0; + } +} +#endif /* HAVE_GETADDRINFO */ |