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/* |
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* Copyright (c) 2014 Sunil Nimmagadda <sunil@nimmagadda.net> |
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* |
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* Permission to use, copy, modify, and distribute this software for any |
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* purpose with or without fee is hereby granted, provided that the above |
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* copyright notice and this permission notice appear in all copies. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
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*/ |
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#include <sys/types.h> |
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#include <sys/socket.h> |
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#include <sys/time.h> |
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#include <sys/tree.h> |
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#include <err.h> |
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#include <errno.h> |
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#include <event.h> |
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#include <netdb.h> |
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#include <pwd.h> |
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#include <signal.h> |
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#include <stdlib.h> |
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#include <string.h> |
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#include <syslog.h> |
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#include <unistd.h> |
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#include "imsgev.h" |
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#include "pop3d.h" |
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#include "ssl.h" |
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#define BACKLOG 5 |
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static void auth_response(struct session *, int); |
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static void pop3_accept(int, short, void *); |
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static void pop3_listen(const char *); |
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static void pop3_pause(int, short, void *); |
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static void pop3d_imsgev(struct imsgev *, int, struct imsg *); |
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static void needfd(struct imsgev *); |
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static void sig_handler(int, short, void *); |
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struct imsgev iev_pop3d; |
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void *ssl_ctx; |
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pid_t |
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pop3_main(int pair[2], struct passwd *pw) |
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{ |
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extern struct session_tree sessions; |
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struct event ev_sigint, ev_sigterm; |
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pid_t pid; |
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pid = fork(); |
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if (pid < 0) |
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fatal("pop3e: fork"); |
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if (pid > 0) |
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return (pid); |
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close(pair[0]); |
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setproctitle("pop3 engine"); |
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SPLAY_INIT(&sessions); |
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event_init(); |
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signal_set(&ev_sigint, SIGINT, sig_handler, NULL); |
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signal_set(&ev_sigterm, SIGTERM, sig_handler, NULL); |
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signal_add(&ev_sigint, NULL); |
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signal_add(&ev_sigterm, NULL); |
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imsgev_init(&iev_pop3d, pair[1], NULL, pop3d_imsgev, needfd); |
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pop3_listen("pop3"); |
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ssl_init(); |
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if ((ssl_ctx = ssl_setup()) == NULL) |
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fatal("ssl_setup failed"); |
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pop3_listen("pop3s"); |
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if (chroot(pw->pw_dir) == -1 || chdir("/") == -1) |
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fatal("chroot"); |
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if (setgroups(1, &pw->pw_gid) || |
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setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) || |
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setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid)) |
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fatal("cannot drop privileges"); |
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if (event_dispatch() < 0) |
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fatal("event_dispatch"); |
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logit(LOG_INFO, "pop3 engine exiting"); |
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_exit(0); |
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} |
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static void |
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pop3_listen(const char *port) |
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{ |
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struct listener *l = NULL; |
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struct addrinfo hints, *res, *res0; |
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int error, opt, serrno, s; |
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const char *cause = NULL; |
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memset(&hints, 0, sizeof(hints)); |
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hints.ai_family = PF_UNSPEC; |
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hints.ai_socktype = SOCK_STREAM; |
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hints.ai_flags = AI_PASSIVE; |
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error = getaddrinfo(NULL, port, &hints, &res0); |
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if (error) |
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errx(1, "%s", gai_strerror(error)); |
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for (res = res0; res != NULL; res = res->ai_next) { |
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s = socket(res->ai_family, res->ai_socktype, res->ai_protocol); |
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if (s == -1) { |
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cause = "socket"; |
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continue; |
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} |
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opt = 1; |
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if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, |
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&opt, sizeof(opt)) == -1) |
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fatal("listener setsockopt(SO_REUSEADDR)"); |
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if (bind(s, res->ai_addr, res->ai_addrlen) == -1) { |
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serrno = errno; |
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cause = "bind"; |
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close(s); |
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errno = serrno; |
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continue; |
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} |
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set_nonblocking(s); |
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if (listen(s, BACKLOG) == -1) |
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fatal("listen"); |
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l = xcalloc(1, sizeof(*l), "pop3_listen"); |
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l->sock = s; |
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if (strcmp(port, "pop3s") == 0) |
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l->flags |= POP3S; |
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event_set(&l->ev, s, EV_READ|EV_PERSIST, pop3_accept, l); |
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event_add(&l->ev, NULL); |
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evtimer_set(&l->pause, pop3_pause, l); |
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} |
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if (l == NULL) |
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errx(1, "%s", cause); |
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freeaddrinfo(res0); |
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} |
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static void |
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pop3_accept(int fd, short events, void *arg) |
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{ |
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struct sockaddr_storage ss; |
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struct listener *l = arg; |
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struct timeval timeout = {1, 0}; |
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socklen_t len; |
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int s; |
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len = sizeof(ss); |
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s = accept(fd, (struct sockaddr *)&ss, &len); |
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if (s == -1) { |
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switch (errno) { |
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case EINTR: |
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case EWOULDBLOCK: |
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case ECONNABORTED: |
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return; |
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case EMFILE: |
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case ENFILE: |
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event_del(&l->ev); |
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evtimer_add(&l->pause, &timeout); |
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return; |
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default: |
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fatalx("accept"); |
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} |
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} |
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set_nonblocking(s); |
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l->ss = ss; |
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session_init(l, s); |
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} |
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static void |
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pop3_pause(int fd, short events, void *arg) |
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{ |
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struct listener *l = arg; |
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event_add(&l->ev, NULL); |
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} |
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static void |
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pop3d_imsgev(struct imsgev *iev, int code, struct imsg *imsg) |
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{ |
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extern struct session_tree sessions; |
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struct session key, *r; |
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switch (code) { |
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case IMSGEV_IMSG: |
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key.id = imsg->hdr.peerid; |
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r = SPLAY_FIND(session_tree, &sessions, &key); |
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if (r == NULL) { |
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logit(LOG_INFO, "%u: session not found", key.id); |
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fatalx("pop3e: session lost"); |
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} |
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switch (imsg->hdr.type) { |
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case IMSG_AUTH: |
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auth_response(r, imsg->fd); |
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break; |
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default: |
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logit(LOG_DEBUG, "%s: unexpected imsg %d", |
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__func__, imsg->hdr.type); |
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break; |
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} |
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break; |
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case IMSGEV_EREAD: |
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case IMSGEV_EWRITE: |
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case IMSGEV_EIMSG: |
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fatal("pop3e: imsgev read/write error"); |
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break; |
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case IMSGEV_DONE: |
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event_loopexit(NULL); |
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break; |
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} |
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} |
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static void |
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auth_response(struct session *s, int fd) |
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{ |
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if (fd == -1) { |
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session_reply(s, "%s", "-ERR auth failed"); |
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io_set_write(&s->io); |
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session_close(s, 1); |
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return; |
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} |
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session_imsgev_init(s, fd); |
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} |
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static void |
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needfd(struct imsgev *iev) |
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{ |
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/* XXX can anything be done to handle fd exhaustion? */ |
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fatalx("pop3e needs an fd"); |
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} |
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static void |
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sig_handler(int sig, short event, void *arg) |
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{ |
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switch (sig) { |
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case SIGINT: |
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case SIGTERM: |
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event_loopexit(NULL); |
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} |
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} |
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