socketd_proxy.C 8.9 KB

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  1. #ifndef _GNU_SOURCE
  2. #define _GNU_SOURCE
  3. #endif
  4. #include <sys/types.h>
  5. #include <sys/socket.h>
  6. #include <map>
  7. #include <set>
  8. #include <iostream>
  9. #include <string>
  10. #include <arpa/inet.h>
  11. #include <unistd.h>
  12. #include <dlfcn.h>
  13. #include <socketd.H>
  14. #include <cpoll/statemachines.H>
  15. #include <cpoll/sendfd.H>
  16. #include <fcntl.h>
  17. #include <poll.h>
  18. using namespace std;
  19. using namespace socketd;
  20. struct scopeLock
  21. {
  22. pthread_mutex_t& mutex;
  23. scopeLock(pthread_mutex_t& m):mutex(m)
  24. {pthread_mutex_lock(&mutex);}
  25. ~scopeLock()
  26. {pthread_mutex_unlock(&mutex);}
  27. };
  28. static void initMutex(pthread_mutex_t& mutex) {
  29. pthread_mutexattr_t attr;
  30. pthread_mutexattr_init(&attr);
  31. pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
  32. int e;
  33. if((e=pthread_mutex_init(&mutex,&attr))!=0) {
  34. const char* err=strerror(e);
  35. throw runtime_error("mutex initialization failed: "+string(err));
  36. }
  37. pthread_mutexattr_destroy(&attr);
  38. }
  39. static pthread_mutex_t mutex;
  40. struct vhostInfo
  41. {
  42. string name;
  43. string authToken;
  44. int fd;
  45. bool attach;
  46. };
  47. struct config
  48. {
  49. map<int, vhostInfo> mappings;
  50. vhostInfo defaultVhost;
  51. bool hasDefault;
  52. };
  53. static bool configLoaded=false;
  54. static config cfg;
  55. static set<int> fds;
  56. struct bufferInfo
  57. {
  58. uint8_t* buf;
  59. int offset;
  60. int len;
  61. };
  62. static map<int,bufferInfo> fdbuffers;
  63. static void loadConfig() {
  64. if(configLoaded)return;
  65. configLoaded=true;
  66. char* tmp=getenv("SOCKETD_FD");
  67. if((cfg.hasDefault=(tmp!=NULL))) {
  68. cfg.defaultVhost.attach=false;
  69. cfg.defaultVhost.fd=atoi(tmp);
  70. }
  71. initMutex(mutex);
  72. //cfg.mappings.insert({12580,{"vhost1",""}});
  73. }
  74. typedef int (*bind_def)(int sockfd, const struct sockaddr *addr,
  75. socklen_t addrlen);
  76. typedef int (*accept_def)(int sockfd, struct sockaddr *addr, socklen_t *addrlen);
  77. typedef int (*accept4_def)(int sockfd, struct sockaddr *addr,
  78. socklen_t *addrlen, int flags);
  79. typedef int (*listen_def)(int sockfd, int backlog);
  80. typedef ssize_t (*recv_def)(int sockfd, void *buf, size_t len, int flags);
  81. typedef ssize_t (*read_def)(int fd, void *buf, size_t count);
  82. typedef int (*shutdown_def)(int sockfd, int how);
  83. typedef int (*close_def)(int fd);
  84. typedef int (*dup2_def)(int oldfd, int newfd);
  85. typedef int (*dup3_def)(int oldfd, int newfd, int flags);
  86. static bind_def prev_bind=NULL;
  87. static accept_def prev_accept=NULL;
  88. static accept4_def prev_accept4=NULL;
  89. static listen_def prev_listen=NULL;
  90. static recv_def prev_recv=NULL;
  91. static read_def prev_read=NULL;
  92. static shutdown_def prev_shutdown=NULL;
  93. static close_def prev_close=NULL;
  94. static dup2_def prev_dup2=NULL;
  95. static dup3_def prev_dup3=NULL;
  96. static int getPort(const struct sockaddr *addr, socklen_t addrlen) {
  97. switch(addr->sa_family) {
  98. case AF_INET:
  99. return ntohs(((const sockaddr_in*)addr)->sin_port);
  100. default:
  101. return -1;
  102. }
  103. }
  104. static int fixBind(int sockfd, const vhostInfo& vh) {
  105. if(vh.attach) {
  106. } else {
  107. if(prev_dup2==NULL) {
  108. prev_dup2=(dup2_def)dlsym(RTLD_NEXT, "dup2");
  109. }
  110. prev_dup2(vh.fd,sockfd);
  111. fds.insert(sockfd);
  112. }
  113. return 0;
  114. }
  115. extern "C" int bind(int sockfd, const struct sockaddr *addr, socklen_t addrlen) {
  116. if(prev_bind==NULL) {
  117. prev_bind=(bind_def)dlsym(RTLD_NEXT, "bind");
  118. }
  119. printf("bind()\n");
  120. int p=getPort(addr,addrlen);
  121. if(p<0) goto aaa;
  122. {
  123. scopeLock l(mutex);
  124. loadConfig();
  125. auto it=cfg.mappings.find(p);
  126. if(it==cfg.mappings.end()) {
  127. if(cfg.hasDefault) return fixBind(sockfd,cfg.defaultVhost);
  128. } else fixBind(sockfd,(*it).second);
  129. }
  130. aaa:
  131. return prev_bind(sockfd,addr,addrlen);
  132. }
  133. extern "C" int listen(int sockfd, int backlog) {
  134. if(prev_listen==NULL) {
  135. prev_listen=(listen_def)dlsym(RTLD_NEXT, "listen");
  136. }
  137. {
  138. scopeLock l(mutex);
  139. if(fds.count(sockfd)>0) return 0;
  140. }
  141. return prev_listen(sockfd, backlog);
  142. }
  143. static int fixAccept(int sockfd, struct sockaddr *addr, socklen_t *addrlen) {
  144. protocolHeader ph;
  145. prot_handleConnection ph1;
  146. int r;
  147. r=recv(sockfd,&ph,sizeof(ph),0);
  148. if(r<0) return -1;
  149. if(r==0) exit(0);
  150. if(r!=sizeof(ph)) {
  151. fprintf(stderr,"failed to read struct protocolHeader (%i bytes) from fd %i: got %i bytes\n"
  152. ,sizeof(protocolHeader),r,sockfd);
  153. exit(0);
  154. }
  155. if(ph.type!=protocolHeader::handleConnection) {
  156. fprintf(stderr,"protocolHeader.type is not handleConnection; it is %i\n",(int)ph.type);
  157. exit(0);
  158. }
  159. if((r=recv(sockfd,&ph1,sizeof(ph1),MSG_WAITALL))!=sizeof(ph1)) {
  160. fprintf(stderr,"failed to read struct prot_handleConnection (%i bytes) from fd %i: got %i bytes\n"
  161. ,sizeof(prot_handleConnection),r,sockfd);
  162. exit(0);
  163. }
  164. aaaaa:
  165. int fd=recvfd(sockfd,MSG_WAITALL);
  166. if(fd<0) {
  167. if(errno==EAGAIN || errno==EWOULDBLOCK) {
  168. pollfd pfd;
  169. pfd.fd = sockfd;
  170. pfd.events = POLLIN;
  171. if(poll(&pfd, 1, -1)<=0) return -1;
  172. if(!(pfd.revents&POLLIN)) return -1;
  173. goto aaaaa;
  174. }
  175. fprintf(stderr,"failed to recvfd() from fd %i; errno: %s\n",sockfd,strerror(errno));
  176. exit(0);
  177. }
  178. if(ph1.bufferLen<=0) return fd;
  179. getpeername(fd, addr, addrlen);
  180. bufferInfo bi;
  181. bi.buf=(uint8_t*)malloc(ph1.bufferLen);
  182. if(bi.buf==NULL) {
  183. close(fd);
  184. errno=ENOMEM;
  185. return -1;
  186. }
  187. bi.offset=0;
  188. bi.len=ph1.bufferLen;
  189. bbbbb:
  190. if((r=recv(sockfd,bi.buf,bi.len,MSG_WAITALL))!=bi.len) {
  191. if(r<0 && (errno==EAGAIN||errno==EWOULDBLOCK)) {
  192. pollfd pfd;
  193. pfd.fd = sockfd;
  194. pfd.events = POLLIN;
  195. if(poll(&pfd, 1, -1)<=0) return -1;
  196. if(!(pfd.revents&POLLIN)) return -1;
  197. goto bbbbb;
  198. }
  199. fprintf(stderr,"failed to read %i bytes from fd %i: got %i bytes; errno: %s\n",bi.len,sockfd,r,strerror(errno));
  200. exit(0);
  201. }
  202. fdbuffers.insert({fd,bi});
  203. ph.type=protocolHeader::ackConnection;
  204. prot_ackConnection ack;
  205. ack.id=ph1.id;
  206. ack.success=true;
  207. if(send(sockfd,&ph,sizeof(ph),MSG_DONTWAIT)==sizeof(ph)) {
  208. send(sockfd,&ack,sizeof(ack),MSG_DONTWAIT);
  209. }
  210. return fd;
  211. }
  212. static int tryFixAccept(int sockfd, struct sockaddr *addr, socklen_t *addrlen) {
  213. {
  214. scopeLock l(mutex);
  215. if(fds.count(sockfd)<=0) return -2;
  216. }
  217. return fixAccept(sockfd, addr, addrlen);
  218. }
  219. extern "C" int accept(int sockfd, struct sockaddr *addr, socklen_t *addrlen) {
  220. if(prev_accept==NULL) {
  221. prev_accept=(accept_def)dlsym(RTLD_NEXT, "accept");
  222. }
  223. int fd=tryFixAccept(sockfd,addr,addrlen);
  224. if(fd==-2) return prev_accept(sockfd, addr, addrlen);
  225. else {
  226. if(fd>=0) {
  227. int f = fcntl(fd, F_GETFL, 0);
  228. f=f&~O_NONBLOCK;
  229. f=f&~O_CLOEXEC;
  230. fcntl(fd, F_SETFL, f);
  231. }
  232. return fd;
  233. }
  234. }
  235. extern "C" int accept4(int sockfd, struct sockaddr *addr, socklen_t *addrlen, int flags) {
  236. if(prev_accept4==NULL) {
  237. prev_accept4=(accept4_def)dlsym(RTLD_NEXT, "accept4");
  238. }
  239. int fd=tryFixAccept(sockfd,addr,addrlen);
  240. if(fd==-2) return prev_accept4(sockfd, addr, addrlen, flags);
  241. else {
  242. if(fd>=0) {
  243. int f = fcntl(fd, F_GETFL, 0);
  244. if(flags&SOCK_NONBLOCK)
  245. f=f|O_NONBLOCK;
  246. else f=f&~O_NONBLOCK;
  247. if(flags&SOCK_CLOEXEC)
  248. f=f|O_CLOEXEC;
  249. else f=f&~O_CLOEXEC;
  250. fcntl(fd, F_SETFL, f);
  251. }
  252. return fd;
  253. }
  254. }
  255. #define __min(x,y) ((x<y)?x:y)
  256. static inline bufferInfo* getBufferInfo(int sockfd) {
  257. scopeLock l(mutex);
  258. auto it=fdbuffers.find(sockfd);
  259. if(it!=fdbuffers.end()) {
  260. return &(*it).second;
  261. } else return NULL;
  262. }
  263. static int fixRead(bufferInfo* bi, int sockfd, void *buf, size_t len) {
  264. //assumes that the application does not call recv() or read() on the same socket
  265. //from 2 threads at once
  266. int minLen=__min(len,bi->len - bi->offset);
  267. memcpy(buf,bi->buf + bi->offset,minLen);
  268. if((bi->offset+=minLen) >= bi->len) {
  269. delete bi->buf;
  270. scopeLock l(mutex);
  271. fdbuffers.erase(sockfd);
  272. }
  273. return minLen;
  274. }
  275. extern "C" ssize_t recv(int sockfd, void *buf, size_t len, int flags) {
  276. if(len<=0) return 0;
  277. if(prev_recv==NULL) {
  278. prev_recv=(recv_def)dlsym(RTLD_NEXT, "recv");
  279. }
  280. bufferInfo* bi=getBufferInfo(sockfd);
  281. if(bi==NULL) return prev_recv(sockfd,buf,len,flags);
  282. return fixRead(bi,sockfd,buf,len);
  283. }
  284. extern "C" ssize_t read(int fd, void *buf, size_t len) {
  285. if(len<=0) return 0;
  286. if(prev_read==NULL) {
  287. prev_read=(read_def)dlsym(RTLD_NEXT, "read");
  288. }
  289. bufferInfo* bi=getBufferInfo(fd);
  290. if(bi==NULL) return prev_read(fd,buf,len);
  291. return fixRead(bi,fd,buf,len);
  292. }
  293. int shutdown(int sockfd, int how) {
  294. if(prev_shutdown==NULL) {
  295. prev_shutdown=(shutdown_def)dlsym(RTLD_NEXT, "shutdown");
  296. }
  297. bool isListen;
  298. {
  299. scopeLock l(mutex);
  300. if(fds.count(sockfd)>0) {
  301. fprintf(stderr,"attempting to shut down listening fd %i\n",sockfd);
  302. return 0;
  303. }
  304. }
  305. return prev_shutdown(sockfd,how);
  306. }
  307. int close(int fd) {
  308. if(prev_close==NULL) {
  309. prev_close=(close_def)dlsym(RTLD_NEXT, "close");
  310. }
  311. {
  312. scopeLock l(mutex);
  313. if(fds.count(fd)>0)
  314. fds.erase(fd);
  315. }
  316. return prev_close(fd);
  317. }
  318. int dup2(int oldfd, int newfd) {
  319. if(prev_dup2==NULL) {
  320. prev_dup2=(dup2_def)dlsym(RTLD_NEXT, "dup2");
  321. }
  322. {
  323. scopeLock l(mutex);
  324. if(fds.count(oldfd)>0)
  325. fds.insert(newfd);
  326. else if(fds.count(newfd)>0)
  327. fds.erase(newfd);
  328. }
  329. return prev_dup2(oldfd,newfd);
  330. }
  331. int dup3(int oldfd, int newfd, int flags) {
  332. if(prev_dup3==NULL) {
  333. prev_dup3=(dup3_def)dlsym(RTLD_NEXT, "dup3");
  334. }
  335. {
  336. scopeLock l(mutex);
  337. if(fds.count(oldfd)>0)
  338. fds.insert(newfd);
  339. else if(fds.count(newfd)>0)
  340. fds.erase(newfd);
  341. }
  342. return prev_dup3(oldfd,newfd,flags);
  343. }