diff options
Diffstat (limited to 'lib/mlibc/options/posix/generic/services.cpp')
| -rw-r--r-- | lib/mlibc/options/posix/generic/services.cpp | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/lib/mlibc/options/posix/generic/services.cpp b/lib/mlibc/options/posix/generic/services.cpp new file mode 100644 index 0000000..8ae0656 --- /dev/null +++ b/lib/mlibc/options/posix/generic/services.cpp @@ -0,0 +1,222 @@ +#include <mlibc/services.hpp> +#include <netdb.h> +#include <stdio.h> +#include <errno.h> +#include <string.h> +#include <stdlib.h> +#include <ctype.h> +#include <sys/socket.h> +#include <netinet/in.h> +#include <mlibc/debug.hpp> + +namespace mlibc { + +static int parse_rest(service_buf &buf, char *end, int proto) { + if (!strncmp(end, "/udp", 4)) { + if (proto == IPPROTO_TCP && proto != -1) + return 0; + buf.protocol = IPPROTO_UDP; + buf.socktype = SOCK_DGRAM; + } else if (!strncmp(end, "/tcp", 4)) { + if (proto == IPPROTO_UDP && proto != -1) + return 0; + buf.protocol = IPPROTO_TCP; + buf.socktype = SOCK_STREAM; + } else { + return 0; + } + + //TODO(geert): also parse aliases. + + return 1; +} + +static int lookup_serv_file_port(service_result &buf, int proto, int port) { + auto file = fopen(_PATH_SERVICES, "r"); + if (!file) { + switch (errno) { + case ENOENT: + case ENOTDIR: + case EACCES: + return -EAI_SERVICE; + default: + return -EAI_SYSTEM; + } + } + + char line_buf[129] = {0}; + char *line = line_buf + 1; + while(fgets(line, 128, file)) { + int name_length = 0; + char *pos; + // easy way to handle comments, just move the end of the line + // to the beginning of the comment + if ((pos = strchr(line, '#'))) { + *pos++ = '\n'; + *pos = '\0'; + } + + char *end = NULL; + for (pos = line; *pos; pos++) { + for (; isalpha(*pos); pos++); + int rport = strtoul(pos, &end, 10); + if (rport != port || rport > 65535) { + pos = end; + continue; + } + + // We have found the port, time to rewind to the start + // of the line. + for (; pos[-1]; pos--) + if(!isspace(pos[-1])) + name_length++; + break; + } + + if (!pos) + continue; + + if (!name_length) + continue; + + auto name = frg::string<MemoryAllocator>(pos, name_length, + getAllocator()); + + struct service_buf sbuf = {}; + sbuf.port = port; + sbuf.name = std::move(name); + if (!parse_rest(sbuf, end, proto)) + continue; + buf.push_back(std::move(sbuf)); + } + + fclose(file); + return buf.size(); +} + +static int lookup_serv_file_name(service_result &buf, const char *name, + int proto) { + auto file = fopen(_PATH_SERVICES, "r"); + if (!file) { + switch (errno) { + case ENOENT: + case ENOTDIR: + case EACCES: + return -EAI_SERVICE; + default: + return -EAI_SYSTEM; + } + } + + char line[128]; + int name_length = strlen(name); + while(fgets(line, 128, file)) { + char *pos; + // easy way to handle comments, just move the end of the line + // to the beginning of the comment + if ((pos = strchr(line, '#'))) { + *pos++ = '\n'; + *pos = '\0'; + } + + for (pos = line; (pos = strstr(pos, name)); pos++) { + // the name must start and end with a space + if (pos > line && !isspace(pos[-1])) + continue; + if (pos[name_length] && !isspace(pos[name_length])) + continue; + break; + } + if (!pos) + continue; + + // Skip the name at the beginning of the line. + for(pos = line; *pos && !isspace(*pos); pos++) + ; + + char *end = NULL; + int port = strtoul(pos, &end, 10); + if (port > 65535 || end == pos) + continue; + + struct service_buf sbuf; + sbuf.port = port; + sbuf.name = frg::string<MemoryAllocator>(name, getAllocator()); + if (!parse_rest(sbuf, end, proto)) + continue; + + buf.push_back(sbuf); + + } + + fclose(file); + return buf.size(); +} + + +// This function returns a negative error code, since a positive +// return code means success. +int lookup_serv_by_name(service_result &buf, const char *name, int proto, + int socktype, int flags) { + switch(socktype) { + case SOCK_STREAM: + if (!proto) + proto = IPPROTO_TCP; + else if (proto != IPPROTO_TCP) + return -EAI_SERVICE; + break; + case SOCK_DGRAM: + if (!proto) + proto = IPPROTO_UDP; + else if (proto != IPPROTO_UDP) + return -EAI_SERVICE; + break; + case 0: + break; + default: + if (name) + return -EAI_SERVICE; + buf[0].port = 0; + buf[0].socktype = socktype; + buf[0].protocol = proto; + return 1; + } + + char *end = nullptr; + unsigned int port = 0; + int count = 0; + + if (name) { + if (!*name) + return -EAI_SERVICE; + port = strtoul(name, &end, 10); + } + // The end pointer is a null pointer so the name was a port + // or the name was not specified. + if (!end || !*end) { + if (proto != IPPROTO_UDP) { + buf[count].port = port; + buf[count].protocol = IPPROTO_TCP; + buf[count].socktype = SOCK_STREAM; + count++; + } + if (proto != IPPROTO_TCP) { + buf[count].port = port; + buf[count].protocol = IPPROTO_UDP; + buf[count].socktype = SOCK_DGRAM; + count++; + } + return count; + } + + if (flags & AI_NUMERICSERV) + return -EAI_NONAME; + + return lookup_serv_file_name(buf, name, proto); +} + +int lookup_serv_by_port(service_result &buf, int proto, int port) { + return lookup_serv_file_port(buf, proto, port); +} + +} // namespace mlibc |